Hospital Medicine

Chronic kidney disease (CKD) is estimated to affect 14% of Americans, but it is likely underdiagnosed because it is often asymptomatic.^1,2 Its prevalence is even higher in patients who undergo surgery—up to 30% in cardiac surgery.³ Its impact on surgical outcomes is substantial.⁴ Importantly, patients with CKD are at higher risk of postoperative acute kidney injury (AKI), which is also associated with adverse outcomes. Thus, it is important to recognize, assess, and manage abnormal renal function in surgical patients.

WHAT IS THE IMPACT ON POSTOPERATIVE OUTCOMES?

Cardiac surgery outcomes

Moreover, in patients undergoing coronary artery bypass grafting (CABG), the worse the renal dysfunction, the higher the long-term mortality rate. Patients with moderate (stage 3) CKD had a 3.5 times higher odds of in-hospital mortality compared with patients with normal renal function, rising to 8.8 with severe (stage 4) and to 9.6 with dialysis-dependent (stage 5) CKD.¹¹

The mechanisms linking CKD with negative cardiac outcomes are unclear, but many possibilities exist. CKD is an independent risk factor for coronary artery disease and shares underlying risk factors such as hypertension and diabetes. Cardiac surgery patients with CKD are also more likely to have diabetes, left ventricular dysfunction, and peripheral vascular disease.

Noncardiac surgery outcomes

CKD is also associated with adverse outcomes in noncardiac surgery patients, especially at higher levels of renal dysfunction.^12–14 For example, in patients who underwent major noncardiac surgery, compared with patients in stage 1 (estimated GFR > 90 mL/min/1.73 m²), the odds ratios for all-cause mortality were as follows:

• 0.8 for patients with stage 2 CKD
• 2.2 in stage 3a
• 2.8 in stage 3b
• 11.3 in stage 4
• 5.8 in stage 5.¹⁴

The association between estimated GFR and all-cause mortality was not statistically significant (P = .071), but statistically significant associations were observed between estimated GFR and major adverse cardiovascular events (P < .001) and hospital length of stay (P < .001).

The association of CKD with major adverse outcomes and death in both cardiac and noncardiac surgical patients demonstrates the importance of understanding this risk, identifying patients with CKD preoperatively, and taking steps to lower the risk.

WHAT IS THE IMPACT OF ACUTE KIDNEY INJURY?

AKI is a common and serious complication of surgery, especially cardiac surgery. It has been associated with higher rates of morbidity, mortality, and cardiovascular events, longer hospital length of stay, and higher cost.

Several groups have proposed criteria for defining AKI and its severity; the KDIGO criteria are the most widely accepted.¹⁵ These define AKI as an increase in serum creatinine concentration of 0.3 mg/dL or more within 48 hours or at least 1.5 times the baseline value within 7 days, or urine volume less than 0.5 mL/kg/hour for more than 6 hours. There are 3 stages of severity:

• Stage 1—an increase in serum creatinine of 1.5 to 1.9 times baseline, an absolute increase of at least 0.3 mg/dL, or urine output less than 0.5 mL/kg/hour for 6 to 12 hours
• Stage 2—an increase in serum creatinine of 2.0 to 2.9 times baseline or urine output less than 0.5 mmL/kg/hour for 12 or more hours
• Stage 3—an increase in serum creatinine of 3 times baseline, an absolute increase of at least 4 mg/dL, initiation of renal replacement therapy, urine output less than 0.3 mL/kg/hour for 24 or more hours, or anuria for 12 or more hours.¹⁵

Multiple factors associated with surgery may contribute to AKI, including hemodynamic instability, volume shifts, blood loss, use of heart-lung bypass, new medications, activation of the inflammatory cascade, oxidative stress, and anemia.

AKI in cardiac surgery

The incidence of AKI is high in cardiac surgery. In a meta-analysis of 46 studies (N = 242,000), its incidence in cardiopulmonary bypass surgery was about 18%, with 2.1% of patients needing renal replacement therapy.¹⁶ However, the incidence varied considerably from study to study, ranging from 1% to 53%, and was influenced by the definition of AKI, the type of cardiac surgery, and the patient population.¹⁶

Cardiac surgery-associated AKI adversely affects outcomes. Several studies have shown that cardiac surgery patients who develop AKI have higher rates of death and stroke.^16–21 More severe AKI confers higher mortality rates, with the highest mortality rate in patients who need renal replacement therapy, approximately 37%.¹⁷ Patients with cardiac surgery-associated AKI also have a longer hospital length of stay and significantly higher costs of care.^17,18

Long-term outcomes are also negatively affected by AKI. In cardiac surgery patients with AKI who had completely recovered renal function by the time they left the hospital, the 2-year incidence rate of CKD was 6.8%, significantly higher than the 0.2% rate in patients who did not develop AKI.¹⁹ The 2-year survival rates also were significantly worse for patients who developed postoperative AKI (82.3% vs 93.7%). Similarly, in patients undergoing CABG who had normal renal function before surgery, those who developed AKI postoperatively had significantly shorter long-term survival rates.²⁰ The effect does not require a large change in renal function. An increase in creatinine as small as 0.3 mg/dL has been associated with a higher rate of death and a long-term risk of end-stage renal disease that is 3 times higher.²¹

Cardiac surgery

CKD is a risk factor not only after cardiac surgery but also after percutaneous procedures. In a meta-analysis of 4,992 patients with CKD who underwent transcatheter aortic valve replacement, both moderate and severe CKD increased the odds of AKI, early stroke, the need for dialysis, and all-cause and cardiovascular mortality at 1 year.^22,23 Increased rates of AKI also have been found in patients with CKD undergoing CABG surgery.²⁴ These results point to a synergistic effect between AKI and CKD, with outcomes much worse in combination than alone.

In cardiac surgery, the most important patient risk factors associated with a higher incidence of postoperative AKI are age older than 75, CKD, preoperative heart failure, and prior myocardial infarction.^19,25 Diabetes is an additional independent risk factor, with type 1 conferring higher risk than type 2.²⁶ Preoperative use of angiotensin-converting enzyme (ACE) inhibitors may or may not be a risk factor for cardiac surgery-associated AKI, with some studies finding increased risk and others finding reduced rates.^27,28

Anemia, which may be related to either patient or surgical risk factors (eg, intraoperative blood loss), also increases the risk of AKI in cardiac surgery.^29,30 A retrospective study of CABG surgery patients found that intraoperative hemoglobin levels below 8 g/dL were associated with a 25% to 30% incidence of AKI, compared with 15% to 20% with hemoglobin levels above 9 g/dL.²⁹ Additionally, having severe hypotension (mean arterial pressure < 50 mm Hg) significantly increased the AKI rates in the low-hemoglobin group.²⁹ Similar results were reported in a later study.³⁰

Among surgical factors, several randomized controlled trials have shown that off-pump CABG is associated with a significantly lower risk of postoperative AKI than on-pump CABG; however, this difference did not translate into any long-term difference in mortality rates.^31,32 Longer cardiopulmonary bypass time is strongly associated with a higher incidence of AKI and postoperative death.³³

Noncardiac surgery

AKI is less common after noncardiac surgery; however, outcomes are severe in patients in whom it occurs. In a study of 15,102 noncardiac surgery patients, only 0.8% developed AKI and 0.1% required renal replacement therapy.³⁴

Risk factors after noncardiac surgery are similar to those after cardiac surgery (Table 3).^34–36 Factors with the greatest impact are older age, peripheral vascular occlusive disease, chronic obstructive pulmonary disease necessitating chronic bronchodilator therapy, high-risk surgery, hepatic disease, emergent or urgent surgery, and high body mass index.

Surgical risk factors include total vasopressor dose administered, use of a vasopressor infusion, and diuretic administration.³⁴ In addition, intraoperative hypotension is associated with a higher risk of AKI, major adverse cardiac events, and 30-day mortality.³⁷

Noncardiac surgery patients with postoperative AKI have significantly higher rates of 30-day readmissions, 1-year progression to end-stage renal disease, and mortality than patients who do not develop AKI.³⁵ Additionally, patients with AKI have significantly higher rates of cardiovascular complications (33.3% vs 11.3%) and death (6.1% vs 0.9%), as well as a significantly longer length of hospital stay.^34,36

CAN WE DECREASE THE IMPACT OF RENAL DISEASE IN SURGERY?

Before surgery, practitioners need to identify patients at risk of AKI, implement possible risk-reduction measures, and, afterward, treat it early in its course if it occurs.

The preoperative visit is the ideal time to assess a patient’s risk of postoperative renal dysfunction. Laboratory tests can identify risks based on surgery type, age, hypertension, the presence of CKD, and medications that affect renal function. However, the basic chemistry panel is abnormal in only 8.2% of patients and affects management in just 2.6%, requiring the clinician to target testing to patients at high risk.³⁸

Patients with a significant degree of renal dysfunction, particularly those previously undiagnosed, may benefit from additional preoperative testing and medication management. Perioperative management of medications that could adversely affect renal function should be carefully considered during the preoperative visit. In addition, the postoperative inpatient team needs to be informed about potentially nephrotoxic medications and medications that are renally cleared. Attention needs to be given to the renal impact of common perioperative medications such as nonsteroidal anti-inflammatory drugs, antibiotics, intravenous contrast, low-molecular-weight heparins, diuretics, ACE inhibitors, and angiotensin II receptor blockers. With the emphasis on opioid-sparing analgesics, it is particularly important to assess the risk of AKI if nonsteroidal anti-inflammatory drugs are part of the pain control plan.

Nephrology referral may help, especially for patients with a GFR less than 45 mL/min. This information enables more informed decision-making regarding the risks of adverse outcomes related to kidney disease.

WHAT TOOLS DO WE HAVE TO DIAGNOSE RENAL INJURY?

Several risk-prediction models have been developed to assess the postoperative risk of AKI in both cardiac and major noncardiac surgery patients. Although these models can identify risk factors, their clinical accuracy and utility have been questioned.

Biomarkers

Early diagnosis is the first step in managing AKI, allowing time to implement measures to minimize its impact.

Serum creatinine testing is widely used to measure renal function and diagnose AKI; however, it does not detect small reductions in renal function, and there is a time lag between renal insult and a rise in creatinine. The result is a delay to diagnosis of AKI.

Biomarkers other than creatinine have been studied for early detection of intraoperative and postoperative renal insult. These novel renal injury markers include the following:

Neutrophil gelatinase-associated lipocalin (NGAL). Two studies looked at plasma NGAL as an early marker of AKI in patients with CKD who were undergoing cardiac surgery.^39,40 One study found that by using NGAL instead of creatinine, postoperative AKI could be diagnosed an average of 20 hours earlier.³⁹ In addition, NGAL helped detect renal recovery earlier than creatinine.⁴⁰ The diagnostic cut-off values of NGAL were different for patients with CKD than for those without CKD.^39,40

Other novel markers include:

• Kidney injury marker 1
• N-acetyl-beta-D-glucosaminidase
• Cysteine C.

Although these biomarkers show some ability to detect renal injury, they provide only modest discrimination and are not widely available for clinical use.⁴¹ Current evidence does not support routine use of these markers in clinical settings.

Interventions to prevent or ameliorate the impact of CKD and AKI on surgical outcomes have been studied most extensively in cardiac surgery patients.

Aspirin. A retrospective study of 3,585 cardiac surgery patients with CKD found that preoperative aspirin use significantly lowered the incidence of postoperative AKI and 30-day mortality compared with patients not using aspirin.⁴² Aspirin use reduced 30-day mortality in CKD stages 1, 2, and 3 by 23.3%, 58%, and 70%, respectively. On the other hand, in the Perioperative Ischemic Evaluation (POISE) trial, in noncardiac surgery patients, neither aspirin nor clonidine started 2 to 4 hours preoperatively and continued up to 30 days after surgery altered the risk of AKI significantly more than placebo.⁴³

Statins have been ineffective in reducing the incidence of AKI in cardiac surgery patients. In fact, a meta-analysis of 8 interventional trials found an increased incidence of AKI in patients in whom statins were started perioperatively.⁴⁴ Erythropoietin was also found to be ineffective in the prevention of perioperative AKI in cardiac surgery patients in a separate study.⁴⁵

The evidence regarding other therapies has also varied.

N-acetylcysteine in high doses reduced the incidence of AKI in patients with CKD stage 3 and 4 undergoing CABG.⁴⁶ Another meta-analysis of 10 studies in cardiac surgery patients published recently did not show any benefit of N-acetylcysteine in reducing AKI.⁴⁷

Human atrial natriuretic peptide, given preoperatively to patients with CKD, reduced the acute and long-term creatinine rise as well as the number of cardiac events after CABG; however, it did not reduce mortality rates.⁴⁸

Renin-angiotensin system inhibitors, given preoperatively to patients with heart failure was associated with a decrease in the incidence of AKI in 1 study.⁴⁹

Dexmedetomidine is a highly selective alpha 2 adrenoreceptor agonist. A recent meta-analysis of 10 clinical trials found it beneficial in reducing the risk of perioperative AKI in cardiac surgery patients.⁵⁰ An earlier meta-analysis had similar results.⁵¹

Levosimendan is an inotropic vasodilator that improves cardiac output and renal perfusion in patients with systolic heart failure, and it has been hypothesized to decrease the risk of AKI after cardiac surgery. Previous data demonstrated that this drug reduced AKI and mortality; however, analysis was limited by small sample size and varying definitions of AKI.⁵² A recent meta-analysis showed that levosimendan was associated with a lower incidence of AKI but was also associated with an increased incidence of atrial fibrillation and no reduction in 30-day mortality.⁵³

Remote ischemic preconditioning is a procedure that subjects the kidneys to brief episodes of ischemia before surgery, protecting them when they are later subjected to prolonged ischemia or reperfusion injury. It has shown initial promising results in preventing AKI. In a randomized controlled trial in 240 patients at high risk of AKI, those who received remote ischemic preconditioning had an AKI incidence of 37.5% compared with 52.5% for controls (P = .02); however, the mortality rate was the same.⁵⁴ Similarly, remote ischemic preconditioning significantly lowered the incidence of AKI in nondiabetic patients undergoing CABG surgery compared with controls.⁵⁵

Fluid management. Renal perfusion is intimately related to the development of AKI, and there is evidence that both hypovolemia and excessive fluid resuscitation can increase the risk of AKI in noncardiac surgery patients.⁵⁶ Because of this, fluid management has also received attention in perioperative AKI. Goal-directed fluid management has been evaluated in noncardiac surgery patients, and it did not show any benefit in preventing AKI.⁵⁷ However, in a more recent retrospective study, postoperative positive fluid balance was associated with increased incidence of AKI compared with zero fluid balance. Negative fluid balance did not appear to have a detrimental effect.⁵⁸

RECOMMENDATIONS

No prophylactic therapy has yet been shown to definitively decrease the risk of postoperative AKI in all patients. Nevertheless, it is important to identify patients at risk during the preoperative visit, especially those with CKD. Many patients undergoing surgery have CKD, placing them at high risk of developing AKI in the perioperative period. The risk is particularly high with cardiac surgery.

Serum creatinine and urine output should be closely monitored perioperatively in at-risk patients. If AKI is diagnosed, practitioners need to identify and ameliorate the cause as early as possible.

Recommendations from KDIGO for perioperative prevention and management of AKI are listed in Table 4.¹⁵ These include avoiding additional nephrotoxic medications and adjusting the doses of renally cleared medications. Also, some patients may benefit from preoperative counseling and specialist referral.

Chronic kidney disease (CKD) is estimated to affect 14% of Americans, but it is likely underdiagnosed because it is often asymptomatic.^1,2 Its prevalence is even higher in patients who undergo surgery—up to 30% in cardiac surgery.³ Its impact on surgical outcomes is substantial.⁴ Importantly, patients with CKD are at higher risk of postoperative acute kidney injury (AKI), which is also associated with adverse outcomes. Thus, it is important to recognize, assess, and manage abnormal renal function in surgical patients.

WHAT IS THE IMPACT ON POSTOPERATIVE OUTCOMES?

Cardiac surgery outcomes

Moreover, in patients undergoing coronary artery bypass grafting (CABG), the worse the renal dysfunction, the higher the long-term mortality rate. Patients with moderate (stage 3) CKD had a 3.5 times higher odds of in-hospital mortality compared with patients with normal renal function, rising to 8.8 with severe (stage 4) and to 9.6 with dialysis-dependent (stage 5) CKD.¹¹

The mechanisms linking CKD with negative cardiac outcomes are unclear, but many possibilities exist. CKD is an independent risk factor for coronary artery disease and shares underlying risk factors such as hypertension and diabetes. Cardiac surgery patients with CKD are also more likely to have diabetes, left ventricular dysfunction, and peripheral vascular disease.

Noncardiac surgery outcomes

CKD is also associated with adverse outcomes in noncardiac surgery patients, especially at higher levels of renal dysfunction.^12–14 For example, in patients who underwent major noncardiac surgery, compared with patients in stage 1 (estimated GFR > 90 mL/min/1.73 m²), the odds ratios for all-cause mortality were as follows:

• 0.8 for patients with stage 2 CKD
• 2.2 in stage 3a
• 2.8 in stage 3b
• 11.3 in stage 4
• 5.8 in stage 5.¹⁴

The association between estimated GFR and all-cause mortality was not statistically significant (P = .071), but statistically significant associations were observed between estimated GFR and major adverse cardiovascular events (P < .001) and hospital length of stay (P < .001).

The association of CKD with major adverse outcomes and death in both cardiac and noncardiac surgical patients demonstrates the importance of understanding this risk, identifying patients with CKD preoperatively, and taking steps to lower the risk.

WHAT IS THE IMPACT OF ACUTE KIDNEY INJURY?

AKI is a common and serious complication of surgery, especially cardiac surgery. It has been associated with higher rates of morbidity, mortality, and cardiovascular events, longer hospital length of stay, and higher cost.

Several groups have proposed criteria for defining AKI and its severity; the KDIGO criteria are the most widely accepted.¹⁵ These define AKI as an increase in serum creatinine concentration of 0.3 mg/dL or more within 48 hours or at least 1.5 times the baseline value within 7 days, or urine volume less than 0.5 mL/kg/hour for more than 6 hours. There are 3 stages of severity:

• Stage 1—an increase in serum creatinine of 1.5 to 1.9 times baseline, an absolute increase of at least 0.3 mg/dL, or urine output less than 0.5 mL/kg/hour for 6 to 12 hours
• Stage 2—an increase in serum creatinine of 2.0 to 2.9 times baseline or urine output less than 0.5 mmL/kg/hour for 12 or more hours
• Stage 3—an increase in serum creatinine of 3 times baseline, an absolute increase of at least 4 mg/dL, initiation of renal replacement therapy, urine output less than 0.3 mL/kg/hour for 24 or more hours, or anuria for 12 or more hours.¹⁵

Multiple factors associated with surgery may contribute to AKI, including hemodynamic instability, volume shifts, blood loss, use of heart-lung bypass, new medications, activation of the inflammatory cascade, oxidative stress, and anemia.

AKI in cardiac surgery

The incidence of AKI is high in cardiac surgery. In a meta-analysis of 46 studies (N = 242,000), its incidence in cardiopulmonary bypass surgery was about 18%, with 2.1% of patients needing renal replacement therapy.¹⁶ However, the incidence varied considerably from study to study, ranging from 1% to 53%, and was influenced by the definition of AKI, the type of cardiac surgery, and the patient population.¹⁶

Cardiac surgery-associated AKI adversely affects outcomes. Several studies have shown that cardiac surgery patients who develop AKI have higher rates of death and stroke.^16–21 More severe AKI confers higher mortality rates, with the highest mortality rate in patients who need renal replacement therapy, approximately 37%.¹⁷ Patients with cardiac surgery-associated AKI also have a longer hospital length of stay and significantly higher costs of care.^17,18

Long-term outcomes are also negatively affected by AKI. In cardiac surgery patients with AKI who had completely recovered renal function by the time they left the hospital, the 2-year incidence rate of CKD was 6.8%, significantly higher than the 0.2% rate in patients who did not develop AKI.¹⁹ The 2-year survival rates also were significantly worse for patients who developed postoperative AKI (82.3% vs 93.7%). Similarly, in patients undergoing CABG who had normal renal function before surgery, those who developed AKI postoperatively had significantly shorter long-term survival rates.²⁰ The effect does not require a large change in renal function. An increase in creatinine as small as 0.3 mg/dL has been associated with a higher rate of death and a long-term risk of end-stage renal disease that is 3 times higher.²¹

Cardiac surgery

CKD is a risk factor not only after cardiac surgery but also after percutaneous procedures. In a meta-analysis of 4,992 patients with CKD who underwent transcatheter aortic valve replacement, both moderate and severe CKD increased the odds of AKI, early stroke, the need for dialysis, and all-cause and cardiovascular mortality at 1 year.^22,23 Increased rates of AKI also have been found in patients with CKD undergoing CABG surgery.²⁴ These results point to a synergistic effect between AKI and CKD, with outcomes much worse in combination than alone.

In cardiac surgery, the most important patient risk factors associated with a higher incidence of postoperative AKI are age older than 75, CKD, preoperative heart failure, and prior myocardial infarction.^19,25 Diabetes is an additional independent risk factor, with type 1 conferring higher risk than type 2.²⁶ Preoperative use of angiotensin-converting enzyme (ACE) inhibitors may or may not be a risk factor for cardiac surgery-associated AKI, with some studies finding increased risk and others finding reduced rates.^27,28

Anemia, which may be related to either patient or surgical risk factors (eg, intraoperative blood loss), also increases the risk of AKI in cardiac surgery.^29,30 A retrospective study of CABG surgery patients found that intraoperative hemoglobin levels below 8 g/dL were associated with a 25% to 30% incidence of AKI, compared with 15% to 20% with hemoglobin levels above 9 g/dL.²⁹ Additionally, having severe hypotension (mean arterial pressure < 50 mm Hg) significantly increased the AKI rates in the low-hemoglobin group.²⁹ Similar results were reported in a later study.³⁰

Among surgical factors, several randomized controlled trials have shown that off-pump CABG is associated with a significantly lower risk of postoperative AKI than on-pump CABG; however, this difference did not translate into any long-term difference in mortality rates.^31,32 Longer cardiopulmonary bypass time is strongly associated with a higher incidence of AKI and postoperative death.³³

Noncardiac surgery

AKI is less common after noncardiac surgery; however, outcomes are severe in patients in whom it occurs. In a study of 15,102 noncardiac surgery patients, only 0.8% developed AKI and 0.1% required renal replacement therapy.³⁴

Risk factors after noncardiac surgery are similar to those after cardiac surgery (Table 3).^34–36 Factors with the greatest impact are older age, peripheral vascular occlusive disease, chronic obstructive pulmonary disease necessitating chronic bronchodilator therapy, high-risk surgery, hepatic disease, emergent or urgent surgery, and high body mass index.

Surgical risk factors include total vasopressor dose administered, use of a vasopressor infusion, and diuretic administration.³⁴ In addition, intraoperative hypotension is associated with a higher risk of AKI, major adverse cardiac events, and 30-day mortality.³⁷

Noncardiac surgery patients with postoperative AKI have significantly higher rates of 30-day readmissions, 1-year progression to end-stage renal disease, and mortality than patients who do not develop AKI.³⁵ Additionally, patients with AKI have significantly higher rates of cardiovascular complications (33.3% vs 11.3%) and death (6.1% vs 0.9%), as well as a significantly longer length of hospital stay.^34,36

CAN WE DECREASE THE IMPACT OF RENAL DISEASE IN SURGERY?

Before surgery, practitioners need to identify patients at risk of AKI, implement possible risk-reduction measures, and, afterward, treat it early in its course if it occurs.

The preoperative visit is the ideal time to assess a patient’s risk of postoperative renal dysfunction. Laboratory tests can identify risks based on surgery type, age, hypertension, the presence of CKD, and medications that affect renal function. However, the basic chemistry panel is abnormal in only 8.2% of patients and affects management in just 2.6%, requiring the clinician to target testing to patients at high risk.³⁸

Patients with a significant degree of renal dysfunction, particularly those previously undiagnosed, may benefit from additional preoperative testing and medication management. Perioperative management of medications that could adversely affect renal function should be carefully considered during the preoperative visit. In addition, the postoperative inpatient team needs to be informed about potentially nephrotoxic medications and medications that are renally cleared. Attention needs to be given to the renal impact of common perioperative medications such as nonsteroidal anti-inflammatory drugs, antibiotics, intravenous contrast, low-molecular-weight heparins, diuretics, ACE inhibitors, and angiotensin II receptor blockers. With the emphasis on opioid-sparing analgesics, it is particularly important to assess the risk of AKI if nonsteroidal anti-inflammatory drugs are part of the pain control plan.

Nephrology referral may help, especially for patients with a GFR less than 45 mL/min. This information enables more informed decision-making regarding the risks of adverse outcomes related to kidney disease.

WHAT TOOLS DO WE HAVE TO DIAGNOSE RENAL INJURY?

Several risk-prediction models have been developed to assess the postoperative risk of AKI in both cardiac and major noncardiac surgery patients. Although these models can identify risk factors, their clinical accuracy and utility have been questioned.

Biomarkers

Early diagnosis is the first step in managing AKI, allowing time to implement measures to minimize its impact.

Serum creatinine testing is widely used to measure renal function and diagnose AKI; however, it does not detect small reductions in renal function, and there is a time lag between renal insult and a rise in creatinine. The result is a delay to diagnosis of AKI.

Biomarkers other than creatinine have been studied for early detection of intraoperative and postoperative renal insult. These novel renal injury markers include the following:

Neutrophil gelatinase-associated lipocalin (NGAL). Two studies looked at plasma NGAL as an early marker of AKI in patients with CKD who were undergoing cardiac surgery.^39,40 One study found that by using NGAL instead of creatinine, postoperative AKI could be diagnosed an average of 20 hours earlier.³⁹ In addition, NGAL helped detect renal recovery earlier than creatinine.⁴⁰ The diagnostic cut-off values of NGAL were different for patients with CKD than for those without CKD.^39,40

Other novel markers include:

• Kidney injury marker 1
• N-acetyl-beta-D-glucosaminidase
• Cysteine C.

Although these biomarkers show some ability to detect renal injury, they provide only modest discrimination and are not widely available for clinical use.⁴¹ Current evidence does not support routine use of these markers in clinical settings.

Interventions to prevent or ameliorate the impact of CKD and AKI on surgical outcomes have been studied most extensively in cardiac surgery patients.

Aspirin. A retrospective study of 3,585 cardiac surgery patients with CKD found that preoperative aspirin use significantly lowered the incidence of postoperative AKI and 30-day mortality compared with patients not using aspirin.⁴² Aspirin use reduced 30-day mortality in CKD stages 1, 2, and 3 by 23.3%, 58%, and 70%, respectively. On the other hand, in the Perioperative Ischemic Evaluation (POISE) trial, in noncardiac surgery patients, neither aspirin nor clonidine started 2 to 4 hours preoperatively and continued up to 30 days after surgery altered the risk of AKI significantly more than placebo.⁴³

Statins have been ineffective in reducing the incidence of AKI in cardiac surgery patients. In fact, a meta-analysis of 8 interventional trials found an increased incidence of AKI in patients in whom statins were started perioperatively.⁴⁴ Erythropoietin was also found to be ineffective in the prevention of perioperative AKI in cardiac surgery patients in a separate study.⁴⁵

The evidence regarding other therapies has also varied.

N-acetylcysteine in high doses reduced the incidence of AKI in patients with CKD stage 3 and 4 undergoing CABG.⁴⁶ Another meta-analysis of 10 studies in cardiac surgery patients published recently did not show any benefit of N-acetylcysteine in reducing AKI.⁴⁷

Human atrial natriuretic peptide, given preoperatively to patients with CKD, reduced the acute and long-term creatinine rise as well as the number of cardiac events after CABG; however, it did not reduce mortality rates.⁴⁸

Renin-angiotensin system inhibitors, given preoperatively to patients with heart failure was associated with a decrease in the incidence of AKI in 1 study.⁴⁹

Dexmedetomidine is a highly selective alpha 2 adrenoreceptor agonist. A recent meta-analysis of 10 clinical trials found it beneficial in reducing the risk of perioperative AKI in cardiac surgery patients.⁵⁰ An earlier meta-analysis had similar results.⁵¹

Levosimendan is an inotropic vasodilator that improves cardiac output and renal perfusion in patients with systolic heart failure, and it has been hypothesized to decrease the risk of AKI after cardiac surgery. Previous data demonstrated that this drug reduced AKI and mortality; however, analysis was limited by small sample size and varying definitions of AKI.⁵² A recent meta-analysis showed that levosimendan was associated with a lower incidence of AKI but was also associated with an increased incidence of atrial fibrillation and no reduction in 30-day mortality.⁵³

Remote ischemic preconditioning is a procedure that subjects the kidneys to brief episodes of ischemia before surgery, protecting them when they are later subjected to prolonged ischemia or reperfusion injury. It has shown initial promising results in preventing AKI. In a randomized controlled trial in 240 patients at high risk of AKI, those who received remote ischemic preconditioning had an AKI incidence of 37.5% compared with 52.5% for controls (P = .02); however, the mortality rate was the same.⁵⁴ Similarly, remote ischemic preconditioning significantly lowered the incidence of AKI in nondiabetic patients undergoing CABG surgery compared with controls.⁵⁵

Fluid management. Renal perfusion is intimately related to the development of AKI, and there is evidence that both hypovolemia and excessive fluid resuscitation can increase the risk of AKI in noncardiac surgery patients.⁵⁶ Because of this, fluid management has also received attention in perioperative AKI. Goal-directed fluid management has been evaluated in noncardiac surgery patients, and it did not show any benefit in preventing AKI.⁵⁷ However, in a more recent retrospective study, postoperative positive fluid balance was associated with increased incidence of AKI compared with zero fluid balance. Negative fluid balance did not appear to have a detrimental effect.⁵⁸

RECOMMENDATIONS

No prophylactic therapy has yet been shown to definitively decrease the risk of postoperative AKI in all patients. Nevertheless, it is important to identify patients at risk during the preoperative visit, especially those with CKD. Many patients undergoing surgery have CKD, placing them at high risk of developing AKI in the perioperative period. The risk is particularly high with cardiac surgery.

Serum creatinine and urine output should be closely monitored perioperatively in at-risk patients. If AKI is diagnosed, practitioners need to identify and ameliorate the cause as early as possible.

Recommendations from KDIGO for perioperative prevention and management of AKI are listed in Table 4.¹⁵ These include avoiding additional nephrotoxic medications and adjusting the doses of renally cleared medications. Also, some patients may benefit from preoperative counseling and specialist referral.

Chronic kidney disease (CKD) is estimated to affect 14% of Americans, but it is likely underdiagnosed because it is often asymptomatic.^1,2 Its prevalence is even higher in patients who undergo surgery—up to 30% in cardiac surgery.³ Its impact on surgical outcomes is substantial.⁴ Importantly, patients with CKD are at higher risk of postoperative acute kidney injury (AKI), which is also associated with adverse outcomes. Thus, it is important to recognize, assess, and manage abnormal renal function in surgical patients.

WHAT IS THE IMPACT ON POSTOPERATIVE OUTCOMES?

Cardiac surgery outcomes

Moreover, in patients undergoing coronary artery bypass grafting (CABG), the worse the renal dysfunction, the higher the long-term mortality rate. Patients with moderate (stage 3) CKD had a 3.5 times higher odds of in-hospital mortality compared with patients with normal renal function, rising to 8.8 with severe (stage 4) and to 9.6 with dialysis-dependent (stage 5) CKD.¹¹

The mechanisms linking CKD with negative cardiac outcomes are unclear, but many possibilities exist. CKD is an independent risk factor for coronary artery disease and shares underlying risk factors such as hypertension and diabetes. Cardiac surgery patients with CKD are also more likely to have diabetes, left ventricular dysfunction, and peripheral vascular disease.

Noncardiac surgery outcomes

CKD is also associated with adverse outcomes in noncardiac surgery patients, especially at higher levels of renal dysfunction.^12–14 For example, in patients who underwent major noncardiac surgery, compared with patients in stage 1 (estimated GFR > 90 mL/min/1.73 m²), the odds ratios for all-cause mortality were as follows:

• 0.8 for patients with stage 2 CKD
• 2.2 in stage 3a
• 2.8 in stage 3b
• 11.3 in stage 4
• 5.8 in stage 5.¹⁴

The association between estimated GFR and all-cause mortality was not statistically significant (P = .071), but statistically significant associations were observed between estimated GFR and major adverse cardiovascular events (P < .001) and hospital length of stay (P < .001).

The association of CKD with major adverse outcomes and death in both cardiac and noncardiac surgical patients demonstrates the importance of understanding this risk, identifying patients with CKD preoperatively, and taking steps to lower the risk.

WHAT IS THE IMPACT OF ACUTE KIDNEY INJURY?

AKI is a common and serious complication of surgery, especially cardiac surgery. It has been associated with higher rates of morbidity, mortality, and cardiovascular events, longer hospital length of stay, and higher cost.

Several groups have proposed criteria for defining AKI and its severity; the KDIGO criteria are the most widely accepted.¹⁵ These define AKI as an increase in serum creatinine concentration of 0.3 mg/dL or more within 48 hours or at least 1.5 times the baseline value within 7 days, or urine volume less than 0.5 mL/kg/hour for more than 6 hours. There are 3 stages of severity:

• Stage 1—an increase in serum creatinine of 1.5 to 1.9 times baseline, an absolute increase of at least 0.3 mg/dL, or urine output less than 0.5 mL/kg/hour for 6 to 12 hours
• Stage 2—an increase in serum creatinine of 2.0 to 2.9 times baseline or urine output less than 0.5 mmL/kg/hour for 12 or more hours
• Stage 3—an increase in serum creatinine of 3 times baseline, an absolute increase of at least 4 mg/dL, initiation of renal replacement therapy, urine output less than 0.3 mL/kg/hour for 24 or more hours, or anuria for 12 or more hours.¹⁵

Multiple factors associated with surgery may contribute to AKI, including hemodynamic instability, volume shifts, blood loss, use of heart-lung bypass, new medications, activation of the inflammatory cascade, oxidative stress, and anemia.

AKI in cardiac surgery

The incidence of AKI is high in cardiac surgery. In a meta-analysis of 46 studies (N = 242,000), its incidence in cardiopulmonary bypass surgery was about 18%, with 2.1% of patients needing renal replacement therapy.¹⁶ However, the incidence varied considerably from study to study, ranging from 1% to 53%, and was influenced by the definition of AKI, the type of cardiac surgery, and the patient population.¹⁶

Cardiac surgery-associated AKI adversely affects outcomes. Several studies have shown that cardiac surgery patients who develop AKI have higher rates of death and stroke.^16–21 More severe AKI confers higher mortality rates, with the highest mortality rate in patients who need renal replacement therapy, approximately 37%.¹⁷ Patients with cardiac surgery-associated AKI also have a longer hospital length of stay and significantly higher costs of care.^17,18

Long-term outcomes are also negatively affected by AKI. In cardiac surgery patients with AKI who had completely recovered renal function by the time they left the hospital, the 2-year incidence rate of CKD was 6.8%, significantly higher than the 0.2% rate in patients who did not develop AKI.¹⁹ The 2-year survival rates also were significantly worse for patients who developed postoperative AKI (82.3% vs 93.7%). Similarly, in patients undergoing CABG who had normal renal function before surgery, those who developed AKI postoperatively had significantly shorter long-term survival rates.²⁰ The effect does not require a large change in renal function. An increase in creatinine as small as 0.3 mg/dL has been associated with a higher rate of death and a long-term risk of end-stage renal disease that is 3 times higher.²¹

Cardiac surgery

CKD is a risk factor not only after cardiac surgery but also after percutaneous procedures. In a meta-analysis of 4,992 patients with CKD who underwent transcatheter aortic valve replacement, both moderate and severe CKD increased the odds of AKI, early stroke, the need for dialysis, and all-cause and cardiovascular mortality at 1 year.^22,23 Increased rates of AKI also have been found in patients with CKD undergoing CABG surgery.²⁴ These results point to a synergistic effect between AKI and CKD, with outcomes much worse in combination than alone.

In cardiac surgery, the most important patient risk factors associated with a higher incidence of postoperative AKI are age older than 75, CKD, preoperative heart failure, and prior myocardial infarction.^19,25 Diabetes is an additional independent risk factor, with type 1 conferring higher risk than type 2.²⁶ Preoperative use of angiotensin-converting enzyme (ACE) inhibitors may or may not be a risk factor for cardiac surgery-associated AKI, with some studies finding increased risk and others finding reduced rates.^27,28

Anemia, which may be related to either patient or surgical risk factors (eg, intraoperative blood loss), also increases the risk of AKI in cardiac surgery.^29,30 A retrospective study of CABG surgery patients found that intraoperative hemoglobin levels below 8 g/dL were associated with a 25% to 30% incidence of AKI, compared with 15% to 20% with hemoglobin levels above 9 g/dL.²⁹ Additionally, having severe hypotension (mean arterial pressure < 50 mm Hg) significantly increased the AKI rates in the low-hemoglobin group.²⁹ Similar results were reported in a later study.³⁰

Among surgical factors, several randomized controlled trials have shown that off-pump CABG is associated with a significantly lower risk of postoperative AKI than on-pump CABG; however, this difference did not translate into any long-term difference in mortality rates.^31,32 Longer cardiopulmonary bypass time is strongly associated with a higher incidence of AKI and postoperative death.³³

Noncardiac surgery

AKI is less common after noncardiac surgery; however, outcomes are severe in patients in whom it occurs. In a study of 15,102 noncardiac surgery patients, only 0.8% developed AKI and 0.1% required renal replacement therapy.³⁴

Risk factors after noncardiac surgery are similar to those after cardiac surgery (Table 3).^34–36 Factors with the greatest impact are older age, peripheral vascular occlusive disease, chronic obstructive pulmonary disease necessitating chronic bronchodilator therapy, high-risk surgery, hepatic disease, emergent or urgent surgery, and high body mass index.

Surgical risk factors include total vasopressor dose administered, use of a vasopressor infusion, and diuretic administration.³⁴ In addition, intraoperative hypotension is associated with a higher risk of AKI, major adverse cardiac events, and 30-day mortality.³⁷

Noncardiac surgery patients with postoperative AKI have significantly higher rates of 30-day readmissions, 1-year progression to end-stage renal disease, and mortality than patients who do not develop AKI.³⁵ Additionally, patients with AKI have significantly higher rates of cardiovascular complications (33.3% vs 11.3%) and death (6.1% vs 0.9%), as well as a significantly longer length of hospital stay.^34,36

CAN WE DECREASE THE IMPACT OF RENAL DISEASE IN SURGERY?

Before surgery, practitioners need to identify patients at risk of AKI, implement possible risk-reduction measures, and, afterward, treat it early in its course if it occurs.

The preoperative visit is the ideal time to assess a patient’s risk of postoperative renal dysfunction. Laboratory tests can identify risks based on surgery type, age, hypertension, the presence of CKD, and medications that affect renal function. However, the basic chemistry panel is abnormal in only 8.2% of patients and affects management in just 2.6%, requiring the clinician to target testing to patients at high risk.³⁸

Patients with a significant degree of renal dysfunction, particularly those previously undiagnosed, may benefit from additional preoperative testing and medication management. Perioperative management of medications that could adversely affect renal function should be carefully considered during the preoperative visit. In addition, the postoperative inpatient team needs to be informed about potentially nephrotoxic medications and medications that are renally cleared. Attention needs to be given to the renal impact of common perioperative medications such as nonsteroidal anti-inflammatory drugs, antibiotics, intravenous contrast, low-molecular-weight heparins, diuretics, ACE inhibitors, and angiotensin II receptor blockers. With the emphasis on opioid-sparing analgesics, it is particularly important to assess the risk of AKI if nonsteroidal anti-inflammatory drugs are part of the pain control plan.

Nephrology referral may help, especially for patients with a GFR less than 45 mL/min. This information enables more informed decision-making regarding the risks of adverse outcomes related to kidney disease.

WHAT TOOLS DO WE HAVE TO DIAGNOSE RENAL INJURY?

Several risk-prediction models have been developed to assess the postoperative risk of AKI in both cardiac and major noncardiac surgery patients. Although these models can identify risk factors, their clinical accuracy and utility have been questioned.

Biomarkers

Early diagnosis is the first step in managing AKI, allowing time to implement measures to minimize its impact.

Serum creatinine testing is widely used to measure renal function and diagnose AKI; however, it does not detect small reductions in renal function, and there is a time lag between renal insult and a rise in creatinine. The result is a delay to diagnosis of AKI.

Biomarkers other than creatinine have been studied for early detection of intraoperative and postoperative renal insult. These novel renal injury markers include the following:

Neutrophil gelatinase-associated lipocalin (NGAL). Two studies looked at plasma NGAL as an early marker of AKI in patients with CKD who were undergoing cardiac surgery.^39,40 One study found that by using NGAL instead of creatinine, postoperative AKI could be diagnosed an average of 20 hours earlier.³⁹ In addition, NGAL helped detect renal recovery earlier than creatinine.⁴⁰ The diagnostic cut-off values of NGAL were different for patients with CKD than for those without CKD.^39,40

Other novel markers include:

• Kidney injury marker 1
• N-acetyl-beta-D-glucosaminidase
• Cysteine C.

Although these biomarkers show some ability to detect renal injury, they provide only modest discrimination and are not widely available for clinical use.⁴¹ Current evidence does not support routine use of these markers in clinical settings.

Interventions to prevent or ameliorate the impact of CKD and AKI on surgical outcomes have been studied most extensively in cardiac surgery patients.

Aspirin. A retrospective study of 3,585 cardiac surgery patients with CKD found that preoperative aspirin use significantly lowered the incidence of postoperative AKI and 30-day mortality compared with patients not using aspirin.⁴² Aspirin use reduced 30-day mortality in CKD stages 1, 2, and 3 by 23.3%, 58%, and 70%, respectively. On the other hand, in the Perioperative Ischemic Evaluation (POISE) trial, in noncardiac surgery patients, neither aspirin nor clonidine started 2 to 4 hours preoperatively and continued up to 30 days after surgery altered the risk of AKI significantly more than placebo.⁴³

Statins have been ineffective in reducing the incidence of AKI in cardiac surgery patients. In fact, a meta-analysis of 8 interventional trials found an increased incidence of AKI in patients in whom statins were started perioperatively.⁴⁴ Erythropoietin was also found to be ineffective in the prevention of perioperative AKI in cardiac surgery patients in a separate study.⁴⁵

The evidence regarding other therapies has also varied.

N-acetylcysteine in high doses reduced the incidence of AKI in patients with CKD stage 3 and 4 undergoing CABG.⁴⁶ Another meta-analysis of 10 studies in cardiac surgery patients published recently did not show any benefit of N-acetylcysteine in reducing AKI.⁴⁷

Human atrial natriuretic peptide, given preoperatively to patients with CKD, reduced the acute and long-term creatinine rise as well as the number of cardiac events after CABG; however, it did not reduce mortality rates.⁴⁸

Renin-angiotensin system inhibitors, given preoperatively to patients with heart failure was associated with a decrease in the incidence of AKI in 1 study.⁴⁹

Dexmedetomidine is a highly selective alpha 2 adrenoreceptor agonist. A recent meta-analysis of 10 clinical trials found it beneficial in reducing the risk of perioperative AKI in cardiac surgery patients.⁵⁰ An earlier meta-analysis had similar results.⁵¹

Levosimendan is an inotropic vasodilator that improves cardiac output and renal perfusion in patients with systolic heart failure, and it has been hypothesized to decrease the risk of AKI after cardiac surgery. Previous data demonstrated that this drug reduced AKI and mortality; however, analysis was limited by small sample size and varying definitions of AKI.⁵² A recent meta-analysis showed that levosimendan was associated with a lower incidence of AKI but was also associated with an increased incidence of atrial fibrillation and no reduction in 30-day mortality.⁵³

Remote ischemic preconditioning is a procedure that subjects the kidneys to brief episodes of ischemia before surgery, protecting them when they are later subjected to prolonged ischemia or reperfusion injury. It has shown initial promising results in preventing AKI. In a randomized controlled trial in 240 patients at high risk of AKI, those who received remote ischemic preconditioning had an AKI incidence of 37.5% compared with 52.5% for controls (P = .02); however, the mortality rate was the same.⁵⁴ Similarly, remote ischemic preconditioning significantly lowered the incidence of AKI in nondiabetic patients undergoing CABG surgery compared with controls.⁵⁵

Fluid management. Renal perfusion is intimately related to the development of AKI, and there is evidence that both hypovolemia and excessive fluid resuscitation can increase the risk of AKI in noncardiac surgery patients.⁵⁶ Because of this, fluid management has also received attention in perioperative AKI. Goal-directed fluid management has been evaluated in noncardiac surgery patients, and it did not show any benefit in preventing AKI.⁵⁷ However, in a more recent retrospective study, postoperative positive fluid balance was associated with increased incidence of AKI compared with zero fluid balance. Negative fluid balance did not appear to have a detrimental effect.⁵⁸

RECOMMENDATIONS

No prophylactic therapy has yet been shown to definitively decrease the risk of postoperative AKI in all patients. Nevertheless, it is important to identify patients at risk during the preoperative visit, especially those with CKD. Many patients undergoing surgery have CKD, placing them at high risk of developing AKI in the perioperative period. The risk is particularly high with cardiac surgery.

Serum creatinine and urine output should be closely monitored perioperatively in at-risk patients. If AKI is diagnosed, practitioners need to identify and ameliorate the cause as early as possible.

Recommendations from KDIGO for perioperative prevention and management of AKI are listed in Table 4.¹⁵ These include avoiding additional nephrotoxic medications and adjusting the doses of renally cleared medications. Also, some patients may benefit from preoperative counseling and specialist referral.

In 2006, the Society of Hospital Medicine (SHM) first published The Core Competencies in Hospital Medicine: A Framework for Curricular Development (henceforth described as the Core Competencies) to help define the role and expectations of hospitalists.^1,2 The Core Competencies provided a framework for evaluating clinical skills and professional expertise within a rapidly developing field and highlighted opportunities for growth. Since the initial development and publication of the Core Competencies, changes in the healthcare landscape and hospitalist practice environment have prompted this revision.

Over the past decade, the field of hospital medicine has experienced exponential growth. In 2005, just over 16,000 hospitalists were practicing in the United States. By 2015, that number had increased to an estimated 44,000 hospitalists, accounting for approximately 6% of the physician workforce.³ Hospitalists have expanded the scope of hospital medicine in many ways. In their roles, hospitalists lead and participate in hospital-based care models that emphasize interprofessional collaboration and a focus on the delivery of high-quality and cost-effective care across a variety of clinical domains (eg, the Choosing Wisely initiative).⁴ They are also engaged in patient safety and quality initiatives that are increasingly being used as benchmarks to rate hospitals and as factors for hospital payment (eg, Hospital Inpatient Value-Based Purchasing Program).⁵ In fact, the American Board of Internal Medicine (ABIM) created a Focused Practice in Hospital Medicine Maintenance of Certification program in response to the growing number of internists choosing to concentrate their practice in the hospital setting. This decision by the ABIM underscores the value that hospitalists bring to improving patient care in the hospital setting. The ABIM also recognizes the Core Competencies as a curricular framework for a focused practice in hospital medicine.⁶

Changes within the educational environment have demanded attentive and active participation by many hospitalists. For example, in 2012, the Accreditation Council for Graduate Medical Education (ACGME) introduced the Milestones Project, a new outcomes-based framework designed to more effectively assess learner performance across the 6 core competencies.⁷ These milestones assessments create intentional opportunities to guide the development of physicians during their training, including in the inpatient environments in which hospitalists practice. Where applicable, existing Core Competencies learning objectives were compared with external sources such as the individual ACGME performance milestones for this revision.

The Core Competencies focus on adult hospital medicine. The Pediatric Hospital Medicine Core Competencies are published separately.⁸ Importantly, the Core Competencies document is not intended to define an absolute set of clinical, procedural, or system-based topics described in textbooks or used by graduate medical education training programs. It does not define or limit the scope of the practice of hospital medicine. Rather, the Core Competencies serve as measurable learning objectives that encourage teaching faculty, practicing hospitalists, and administrators to develop individual skill sets and programs to improve patient care contextualized to the needs of an individual, care setting, or institution. To permit this flexibility, individual chapter-specific objectives are intentionally general in nature. Finally, the Core Competencies document is not a set of practice guidelines, nor does it offer any representation of a “standard of care.” Readers are encouraged to explore the article by McKean et al.⁹ to review examples of application of the Core Competencies and suggestions for curricular development.

The purpose of this article is to describe the criteria for inclusion of new chapters in the Core Competencies and the methodology of the review and revision process. It outlines the process of initial review and editing of the existing chapters; needs assessment for new topics; new chapter production; and the process of review and revision of individual chapters to create the complete document. The revised Core Competencies document is available online at http://www.journalofhospitalmedicine.com/jhospmed/issue/134981/journal-hospital-medicine-124-suppl-1.

In 2012, the Society of Hospital Medicine (SHM) Education Committee created a Core Competencies Task Force (CCTF) in response to the SHM Board of Directors’ charge that it review and update the initial Core Competencies document. The CCTF comprised of 5 physician SHM Education Committee members and one SHM staff representative. CCTF membership included hospitalists with an interest and familiarity with the Core Competencies document. The SHM Education Committee nominated the CCTF chair, who determined the optimal size, qualifications, and composition of the task force with approval from the Committee. The CCTF communicated through frequent conference calls and via e-mail correspondence to conduct an initial review of the existing chapters and to perform a needs assessment for new topics.

Individual Chapter Review

The SHM Education Committee provided critical input and approved the chapter review process designed by the CCTF (Figure). The CCTF reviewed each chapter of the Core Competencies document to assess its continuing relevance to the field of hospital medicine with a standardized tool (Appendix 1). The process required that at least 2 CCTF members reviewed each chapter. Preliminary reviewers assessed the current relevance of each chapter, determined whether individual learning objectives required additional investigation or modification, and developed new learning objectives to fill any educational gaps. All CCTF members then discussed assimilated feedback from the initial CCTF review, using consensus decision making to determine chapter changes and modifications. The CCTF found each of the existing chapters to be relevant to the field and identified none for removal.

The CCTF rewrote all chapters. It then disseminated proposed chapter changes to a panel of diverse independent reviewers to solicit suggestions and comments to ensure a multidisciplinary and balanced review process. Independent reviewers included authors of the original Core Competencies chapters, invited content experts, and members of the SHM Education Committee. When appropriate, corresponding SHM Committees reviewed individual chapters for updates and revisions. For example, the SHM Hospital Quality and Patient Safety Committee reviewed the chapters on patient safety and quality improvement, and the SHM Practice Management Committee reviewed the chapter on management practices. Four CCTF section editors managed an independent portfolio of chapters. Each CCTF section editor assimilated the various draft versions, corresponded with individual reviewers when necessary, and compiled the changes into a subsequent draft. This process ensured that the final version of every chapter reflected the thoughtful input from all parties involved in the review. Throughout the process, the CCTF used consensus decision making to adjudicate chapter changes and modifications. The 2006 Core Competencies Editorial team also reviewed the revision and provided critical input. The SHM Education Committee and the SHM Board of Directors reviewed and approved the final version of the Core Competencies document.

Needs Assessment and Selection of New Core Competency Chapters

The CCTF issued a call for new topics to the members of the SHM Education Committee for inclusion in the Core Competencies. Topics were also identified from the following sources: the top 100 adult medical diagnoses at hospital discharge in the Healthcare Cost and Utilization Project database in 2010; topics in hospital medicine textbooks; curricula presented at the 3 most recent SHM annual meetings; and responses from SHM annual meeting surveys. Table 1 lists the topics considered for addition.

Members of the SHM Education Committee rated each of the potential topics considered for inclusion based on the following characteristics: relevance to the field of hospital medicine; intersection of the topic with medical subspecialties; and its appropriateness as a separate, stand-alone chapter. In addition, topics more frequently encountered by hospitalists, those deemed clinically important with a known risk of complications or management inconsistencies, and those with significant opportunities for quality improvement initiatives carried more weight. Syncope and hyponatremia were the only 2 clinical conditions identified that met all of the inclusion criteria. No additional topics met the criteria for new chapter development in the Procedures or Healthcare Systems sections. The SHM Education Committee identified the use of point-of-care ultrasonography as an important advancement in the field. Where appropriate, the individual procedure chapters now include a new competency-based objective highlighting its role. In addition, a separate SHM task force is working to develop a practice guideline for the use of point-of-care ultrasonography by hospitalists.

Contributors

The SHM Education Committee determined authorship for the new chapters (syncope and hyponatremia). It assigned 2 CCTF members with content expertise and familiarity with the Core Competencies to each author one chapter. Given the limited number of new chapters, it made a decision to develop the content internally rather than through an open-call for authorship nominations to practicing SHM members. The authors made an effort to maintain consistency with the educational theory used to develop the initial Core Competencies. Each of the new topics underwent rigorous review as previously described, including additional independent reviews by hospitalists with content expertise in these areas.

Following the same format as the earlier version, the 2017 Core Competencies revision contains 53 chapters, divided into 3 sections—Clinical Conditions, Procedures, and Healthcare Systems (Table 2) —all integral components of the practice of hospital medicine. The design allows individual chapters to stand alone. However, each chapter should be considered in the context of the entire document because a particular concept may be only briefly discussed in one chapter, but described in greater depth in another given the potential overlap across topics.

The chapters maintain the same content structure as the original version. Each chapter begins with an introductory paragraph followed by a list of competency-based objectives grouped in subsections according to the educational theory of learning domains: cognitive (knowledge), psychomotor (skills), and affective (attitudes).¹⁰ In addition, a subsection for System Organization and Improvement is included in the Clinical Conditions and Procedure chapters to emphasize the importance of interprofessional collaboration for optimal patient care. These subsections were not included in the Healthcare Systems chapters, as system organization and improvement is intrinsic to these subjects.

The introductory paragraph provides background information and describes how the chapter remains relevant to the current practice of hospital medicine. Individual competency-based objectives outline a relevant concept and expected level of proficiency as defined by Bloom’s taxonomy.¹⁰ New objectives reflect changes in the healthcare landscape over the past decade or further enhance each chapter’s concepts. Chapter authors made an effort to develop chapter and learning objective concepts that are consistent with external resources such as the ACGME Milestones Project and practice guideline objectives developed by a variety of professional organizations.

The Core Competencies document serves as a resource for hospitalists and hospital medicine programs to evaluate, develop, and improve individual and collective skills and the practice environment. The Core Competencies also provide a framework for medical school clerkship directors and residency and fellowship program directors, as well as course directors of Continuing Medical Education programs, to develop curricula to enhance educational experiences for trainees and hospital medicine providers. The updates in every chapter in this revision to the Core Competencies reflects the changes in the healthcare landscape and hospitalist practice environment over the past decade, and we encourage readers to revisit the entire compendium. Table 3 highlights some of the salient changes in this revision.

Hospital medicine continues to evolve as a specialty. The Core Competencies define hospitalists as agents of change and foster the development of a culture of safe and effective patient care within the hospital environment. Although the CCTF hopes that the Core Competencies will preserve their relevance over time, it recognizes the importance of their periodic reevaluation and adaptation. Additionally, SHM developed the Core Competencies primarily for physicians practicing as hospitalists. As the number of physician assistants and nurse practitioners engaged in the practice of hospital medicine increases, and hospital medicine expands into nontraditional specialties such as surgical comanagement, it may be necessary to consider the development of additional or separate Hospital Medicine Core Competencies tailored to the needs of these subsets of clinicians.

Acknowledgments

The authors and the CCTF are immensely grateful to Nick Marzano for project coordination and Abbie Young for her assistance with medical editing and chapter formatting. We extend our sincerest appreciation and gratitude to the index team of authors and editors whose efforts laid the foundation for this body of work. The initial development and this revision of the Core Competencies would not have been possible without the support and assistance of the SHM staff, the SHM Education Committee, and the scores of contributors and reviewers who participated in its creation (complete list of individuals is available in Appendix 2). We thank everyone for his or her invaluable input and effort.

Disclosures

The Society of Hospital Medicine (SHM) provided administrative support for project coordination. SHM, or any of its representatives, had no role in the development of topic areas, refinement, or vetting of the topic list. No member of the Core Competencies Task Force or the SHM Education Committee received compensation for their participation in revising the Core Competencies. The authors report no conflicts of interest.

In 2006, the Society of Hospital Medicine (SHM) first published The Core Competencies in Hospital Medicine: A Framework for Curricular Development (henceforth described as the Core Competencies) to help define the role and expectations of hospitalists.^1,2 The Core Competencies provided a framework for evaluating clinical skills and professional expertise within a rapidly developing field and highlighted opportunities for growth. Since the initial development and publication of the Core Competencies, changes in the healthcare landscape and hospitalist practice environment have prompted this revision.

Over the past decade, the field of hospital medicine has experienced exponential growth. In 2005, just over 16,000 hospitalists were practicing in the United States. By 2015, that number had increased to an estimated 44,000 hospitalists, accounting for approximately 6% of the physician workforce.³ Hospitalists have expanded the scope of hospital medicine in many ways. In their roles, hospitalists lead and participate in hospital-based care models that emphasize interprofessional collaboration and a focus on the delivery of high-quality and cost-effective care across a variety of clinical domains (eg, the Choosing Wisely initiative).⁴ They are also engaged in patient safety and quality initiatives that are increasingly being used as benchmarks to rate hospitals and as factors for hospital payment (eg, Hospital Inpatient Value-Based Purchasing Program).⁵ In fact, the American Board of Internal Medicine (ABIM) created a Focused Practice in Hospital Medicine Maintenance of Certification program in response to the growing number of internists choosing to concentrate their practice in the hospital setting. This decision by the ABIM underscores the value that hospitalists bring to improving patient care in the hospital setting. The ABIM also recognizes the Core Competencies as a curricular framework for a focused practice in hospital medicine.⁶

Changes within the educational environment have demanded attentive and active participation by many hospitalists. For example, in 2012, the Accreditation Council for Graduate Medical Education (ACGME) introduced the Milestones Project, a new outcomes-based framework designed to more effectively assess learner performance across the 6 core competencies.⁷ These milestones assessments create intentional opportunities to guide the development of physicians during their training, including in the inpatient environments in which hospitalists practice. Where applicable, existing Core Competencies learning objectives were compared with external sources such as the individual ACGME performance milestones for this revision.

The Core Competencies focus on adult hospital medicine. The Pediatric Hospital Medicine Core Competencies are published separately.⁸ Importantly, the Core Competencies document is not intended to define an absolute set of clinical, procedural, or system-based topics described in textbooks or used by graduate medical education training programs. It does not define or limit the scope of the practice of hospital medicine. Rather, the Core Competencies serve as measurable learning objectives that encourage teaching faculty, practicing hospitalists, and administrators to develop individual skill sets and programs to improve patient care contextualized to the needs of an individual, care setting, or institution. To permit this flexibility, individual chapter-specific objectives are intentionally general in nature. Finally, the Core Competencies document is not a set of practice guidelines, nor does it offer any representation of a “standard of care.” Readers are encouraged to explore the article by McKean et al.⁹ to review examples of application of the Core Competencies and suggestions for curricular development.

The purpose of this article is to describe the criteria for inclusion of new chapters in the Core Competencies and the methodology of the review and revision process. It outlines the process of initial review and editing of the existing chapters; needs assessment for new topics; new chapter production; and the process of review and revision of individual chapters to create the complete document. The revised Core Competencies document is available online at http://www.journalofhospitalmedicine.com/jhospmed/issue/134981/journal-hospital-medicine-124-suppl-1.

In 2012, the Society of Hospital Medicine (SHM) Education Committee created a Core Competencies Task Force (CCTF) in response to the SHM Board of Directors’ charge that it review and update the initial Core Competencies document. The CCTF comprised of 5 physician SHM Education Committee members and one SHM staff representative. CCTF membership included hospitalists with an interest and familiarity with the Core Competencies document. The SHM Education Committee nominated the CCTF chair, who determined the optimal size, qualifications, and composition of the task force with approval from the Committee. The CCTF communicated through frequent conference calls and via e-mail correspondence to conduct an initial review of the existing chapters and to perform a needs assessment for new topics.

Individual Chapter Review

The SHM Education Committee provided critical input and approved the chapter review process designed by the CCTF (Figure). The CCTF reviewed each chapter of the Core Competencies document to assess its continuing relevance to the field of hospital medicine with a standardized tool (Appendix 1). The process required that at least 2 CCTF members reviewed each chapter. Preliminary reviewers assessed the current relevance of each chapter, determined whether individual learning objectives required additional investigation or modification, and developed new learning objectives to fill any educational gaps. All CCTF members then discussed assimilated feedback from the initial CCTF review, using consensus decision making to determine chapter changes and modifications. The CCTF found each of the existing chapters to be relevant to the field and identified none for removal.

The CCTF rewrote all chapters. It then disseminated proposed chapter changes to a panel of diverse independent reviewers to solicit suggestions and comments to ensure a multidisciplinary and balanced review process. Independent reviewers included authors of the original Core Competencies chapters, invited content experts, and members of the SHM Education Committee. When appropriate, corresponding SHM Committees reviewed individual chapters for updates and revisions. For example, the SHM Hospital Quality and Patient Safety Committee reviewed the chapters on patient safety and quality improvement, and the SHM Practice Management Committee reviewed the chapter on management practices. Four CCTF section editors managed an independent portfolio of chapters. Each CCTF section editor assimilated the various draft versions, corresponded with individual reviewers when necessary, and compiled the changes into a subsequent draft. This process ensured that the final version of every chapter reflected the thoughtful input from all parties involved in the review. Throughout the process, the CCTF used consensus decision making to adjudicate chapter changes and modifications. The 2006 Core Competencies Editorial team also reviewed the revision and provided critical input. The SHM Education Committee and the SHM Board of Directors reviewed and approved the final version of the Core Competencies document.

Needs Assessment and Selection of New Core Competency Chapters

The CCTF issued a call for new topics to the members of the SHM Education Committee for inclusion in the Core Competencies. Topics were also identified from the following sources: the top 100 adult medical diagnoses at hospital discharge in the Healthcare Cost and Utilization Project database in 2010; topics in hospital medicine textbooks; curricula presented at the 3 most recent SHM annual meetings; and responses from SHM annual meeting surveys. Table 1 lists the topics considered for addition.

Members of the SHM Education Committee rated each of the potential topics considered for inclusion based on the following characteristics: relevance to the field of hospital medicine; intersection of the topic with medical subspecialties; and its appropriateness as a separate, stand-alone chapter. In addition, topics more frequently encountered by hospitalists, those deemed clinically important with a known risk of complications or management inconsistencies, and those with significant opportunities for quality improvement initiatives carried more weight. Syncope and hyponatremia were the only 2 clinical conditions identified that met all of the inclusion criteria. No additional topics met the criteria for new chapter development in the Procedures or Healthcare Systems sections. The SHM Education Committee identified the use of point-of-care ultrasonography as an important advancement in the field. Where appropriate, the individual procedure chapters now include a new competency-based objective highlighting its role. In addition, a separate SHM task force is working to develop a practice guideline for the use of point-of-care ultrasonography by hospitalists.

Contributors

The SHM Education Committee determined authorship for the new chapters (syncope and hyponatremia). It assigned 2 CCTF members with content expertise and familiarity with the Core Competencies to each author one chapter. Given the limited number of new chapters, it made a decision to develop the content internally rather than through an open-call for authorship nominations to practicing SHM members. The authors made an effort to maintain consistency with the educational theory used to develop the initial Core Competencies. Each of the new topics underwent rigorous review as previously described, including additional independent reviews by hospitalists with content expertise in these areas.

Following the same format as the earlier version, the 2017 Core Competencies revision contains 53 chapters, divided into 3 sections—Clinical Conditions, Procedures, and Healthcare Systems (Table 2) —all integral components of the practice of hospital medicine. The design allows individual chapters to stand alone. However, each chapter should be considered in the context of the entire document because a particular concept may be only briefly discussed in one chapter, but described in greater depth in another given the potential overlap across topics.

The chapters maintain the same content structure as the original version. Each chapter begins with an introductory paragraph followed by a list of competency-based objectives grouped in subsections according to the educational theory of learning domains: cognitive (knowledge), psychomotor (skills), and affective (attitudes).¹⁰ In addition, a subsection for System Organization and Improvement is included in the Clinical Conditions and Procedure chapters to emphasize the importance of interprofessional collaboration for optimal patient care. These subsections were not included in the Healthcare Systems chapters, as system organization and improvement is intrinsic to these subjects.

The introductory paragraph provides background information and describes how the chapter remains relevant to the current practice of hospital medicine. Individual competency-based objectives outline a relevant concept and expected level of proficiency as defined by Bloom’s taxonomy.¹⁰ New objectives reflect changes in the healthcare landscape over the past decade or further enhance each chapter’s concepts. Chapter authors made an effort to develop chapter and learning objective concepts that are consistent with external resources such as the ACGME Milestones Project and practice guideline objectives developed by a variety of professional organizations.

The Core Competencies document serves as a resource for hospitalists and hospital medicine programs to evaluate, develop, and improve individual and collective skills and the practice environment. The Core Competencies also provide a framework for medical school clerkship directors and residency and fellowship program directors, as well as course directors of Continuing Medical Education programs, to develop curricula to enhance educational experiences for trainees and hospital medicine providers. The updates in every chapter in this revision to the Core Competencies reflects the changes in the healthcare landscape and hospitalist practice environment over the past decade, and we encourage readers to revisit the entire compendium. Table 3 highlights some of the salient changes in this revision.

Hospital medicine continues to evolve as a specialty. The Core Competencies define hospitalists as agents of change and foster the development of a culture of safe and effective patient care within the hospital environment. Although the CCTF hopes that the Core Competencies will preserve their relevance over time, it recognizes the importance of their periodic reevaluation and adaptation. Additionally, SHM developed the Core Competencies primarily for physicians practicing as hospitalists. As the number of physician assistants and nurse practitioners engaged in the practice of hospital medicine increases, and hospital medicine expands into nontraditional specialties such as surgical comanagement, it may be necessary to consider the development of additional or separate Hospital Medicine Core Competencies tailored to the needs of these subsets of clinicians.

Acknowledgments

The authors and the CCTF are immensely grateful to Nick Marzano for project coordination and Abbie Young for her assistance with medical editing and chapter formatting. We extend our sincerest appreciation and gratitude to the index team of authors and editors whose efforts laid the foundation for this body of work. The initial development and this revision of the Core Competencies would not have been possible without the support and assistance of the SHM staff, the SHM Education Committee, and the scores of contributors and reviewers who participated in its creation (complete list of individuals is available in Appendix 2). We thank everyone for his or her invaluable input and effort.

Disclosures

The Society of Hospital Medicine (SHM) provided administrative support for project coordination. SHM, or any of its representatives, had no role in the development of topic areas, refinement, or vetting of the topic list. No member of the Core Competencies Task Force or the SHM Education Committee received compensation for their participation in revising the Core Competencies. The authors report no conflicts of interest.

In 2006, the Society of Hospital Medicine (SHM) first published The Core Competencies in Hospital Medicine: A Framework for Curricular Development (henceforth described as the Core Competencies) to help define the role and expectations of hospitalists.^1,2 The Core Competencies provided a framework for evaluating clinical skills and professional expertise within a rapidly developing field and highlighted opportunities for growth. Since the initial development and publication of the Core Competencies, changes in the healthcare landscape and hospitalist practice environment have prompted this revision.

Over the past decade, the field of hospital medicine has experienced exponential growth. In 2005, just over 16,000 hospitalists were practicing in the United States. By 2015, that number had increased to an estimated 44,000 hospitalists, accounting for approximately 6% of the physician workforce.³ Hospitalists have expanded the scope of hospital medicine in many ways. In their roles, hospitalists lead and participate in hospital-based care models that emphasize interprofessional collaboration and a focus on the delivery of high-quality and cost-effective care across a variety of clinical domains (eg, the Choosing Wisely initiative).⁴ They are also engaged in patient safety and quality initiatives that are increasingly being used as benchmarks to rate hospitals and as factors for hospital payment (eg, Hospital Inpatient Value-Based Purchasing Program).⁵ In fact, the American Board of Internal Medicine (ABIM) created a Focused Practice in Hospital Medicine Maintenance of Certification program in response to the growing number of internists choosing to concentrate their practice in the hospital setting. This decision by the ABIM underscores the value that hospitalists bring to improving patient care in the hospital setting. The ABIM also recognizes the Core Competencies as a curricular framework for a focused practice in hospital medicine.⁶

Changes within the educational environment have demanded attentive and active participation by many hospitalists. For example, in 2012, the Accreditation Council for Graduate Medical Education (ACGME) introduced the Milestones Project, a new outcomes-based framework designed to more effectively assess learner performance across the 6 core competencies.⁷ These milestones assessments create intentional opportunities to guide the development of physicians during their training, including in the inpatient environments in which hospitalists practice. Where applicable, existing Core Competencies learning objectives were compared with external sources such as the individual ACGME performance milestones for this revision.

The Core Competencies focus on adult hospital medicine. The Pediatric Hospital Medicine Core Competencies are published separately.⁸ Importantly, the Core Competencies document is not intended to define an absolute set of clinical, procedural, or system-based topics described in textbooks or used by graduate medical education training programs. It does not define or limit the scope of the practice of hospital medicine. Rather, the Core Competencies serve as measurable learning objectives that encourage teaching faculty, practicing hospitalists, and administrators to develop individual skill sets and programs to improve patient care contextualized to the needs of an individual, care setting, or institution. To permit this flexibility, individual chapter-specific objectives are intentionally general in nature. Finally, the Core Competencies document is not a set of practice guidelines, nor does it offer any representation of a “standard of care.” Readers are encouraged to explore the article by McKean et al.⁹ to review examples of application of the Core Competencies and suggestions for curricular development.

The purpose of this article is to describe the criteria for inclusion of new chapters in the Core Competencies and the methodology of the review and revision process. It outlines the process of initial review and editing of the existing chapters; needs assessment for new topics; new chapter production; and the process of review and revision of individual chapters to create the complete document. The revised Core Competencies document is available online at http://www.journalofhospitalmedicine.com/jhospmed/issue/134981/journal-hospital-medicine-124-suppl-1.

In 2012, the Society of Hospital Medicine (SHM) Education Committee created a Core Competencies Task Force (CCTF) in response to the SHM Board of Directors’ charge that it review and update the initial Core Competencies document. The CCTF comprised of 5 physician SHM Education Committee members and one SHM staff representative. CCTF membership included hospitalists with an interest and familiarity with the Core Competencies document. The SHM Education Committee nominated the CCTF chair, who determined the optimal size, qualifications, and composition of the task force with approval from the Committee. The CCTF communicated through frequent conference calls and via e-mail correspondence to conduct an initial review of the existing chapters and to perform a needs assessment for new topics.

Individual Chapter Review

The SHM Education Committee provided critical input and approved the chapter review process designed by the CCTF (Figure). The CCTF reviewed each chapter of the Core Competencies document to assess its continuing relevance to the field of hospital medicine with a standardized tool (Appendix 1). The process required that at least 2 CCTF members reviewed each chapter. Preliminary reviewers assessed the current relevance of each chapter, determined whether individual learning objectives required additional investigation or modification, and developed new learning objectives to fill any educational gaps. All CCTF members then discussed assimilated feedback from the initial CCTF review, using consensus decision making to determine chapter changes and modifications. The CCTF found each of the existing chapters to be relevant to the field and identified none for removal.

The CCTF rewrote all chapters. It then disseminated proposed chapter changes to a panel of diverse independent reviewers to solicit suggestions and comments to ensure a multidisciplinary and balanced review process. Independent reviewers included authors of the original Core Competencies chapters, invited content experts, and members of the SHM Education Committee. When appropriate, corresponding SHM Committees reviewed individual chapters for updates and revisions. For example, the SHM Hospital Quality and Patient Safety Committee reviewed the chapters on patient safety and quality improvement, and the SHM Practice Management Committee reviewed the chapter on management practices. Four CCTF section editors managed an independent portfolio of chapters. Each CCTF section editor assimilated the various draft versions, corresponded with individual reviewers when necessary, and compiled the changes into a subsequent draft. This process ensured that the final version of every chapter reflected the thoughtful input from all parties involved in the review. Throughout the process, the CCTF used consensus decision making to adjudicate chapter changes and modifications. The 2006 Core Competencies Editorial team also reviewed the revision and provided critical input. The SHM Education Committee and the SHM Board of Directors reviewed and approved the final version of the Core Competencies document.

Needs Assessment and Selection of New Core Competency Chapters

The CCTF issued a call for new topics to the members of the SHM Education Committee for inclusion in the Core Competencies. Topics were also identified from the following sources: the top 100 adult medical diagnoses at hospital discharge in the Healthcare Cost and Utilization Project database in 2010; topics in hospital medicine textbooks; curricula presented at the 3 most recent SHM annual meetings; and responses from SHM annual meeting surveys. Table 1 lists the topics considered for addition.

Members of the SHM Education Committee rated each of the potential topics considered for inclusion based on the following characteristics: relevance to the field of hospital medicine; intersection of the topic with medical subspecialties; and its appropriateness as a separate, stand-alone chapter. In addition, topics more frequently encountered by hospitalists, those deemed clinically important with a known risk of complications or management inconsistencies, and those with significant opportunities for quality improvement initiatives carried more weight. Syncope and hyponatremia were the only 2 clinical conditions identified that met all of the inclusion criteria. No additional topics met the criteria for new chapter development in the Procedures or Healthcare Systems sections. The SHM Education Committee identified the use of point-of-care ultrasonography as an important advancement in the field. Where appropriate, the individual procedure chapters now include a new competency-based objective highlighting its role. In addition, a separate SHM task force is working to develop a practice guideline for the use of point-of-care ultrasonography by hospitalists.

Contributors

The SHM Education Committee determined authorship for the new chapters (syncope and hyponatremia). It assigned 2 CCTF members with content expertise and familiarity with the Core Competencies to each author one chapter. Given the limited number of new chapters, it made a decision to develop the content internally rather than through an open-call for authorship nominations to practicing SHM members. The authors made an effort to maintain consistency with the educational theory used to develop the initial Core Competencies. Each of the new topics underwent rigorous review as previously described, including additional independent reviews by hospitalists with content expertise in these areas.

Following the same format as the earlier version, the 2017 Core Competencies revision contains 53 chapters, divided into 3 sections—Clinical Conditions, Procedures, and Healthcare Systems (Table 2) —all integral components of the practice of hospital medicine. The design allows individual chapters to stand alone. However, each chapter should be considered in the context of the entire document because a particular concept may be only briefly discussed in one chapter, but described in greater depth in another given the potential overlap across topics.

The chapters maintain the same content structure as the original version. Each chapter begins with an introductory paragraph followed by a list of competency-based objectives grouped in subsections according to the educational theory of learning domains: cognitive (knowledge), psychomotor (skills), and affective (attitudes).¹⁰ In addition, a subsection for System Organization and Improvement is included in the Clinical Conditions and Procedure chapters to emphasize the importance of interprofessional collaboration for optimal patient care. These subsections were not included in the Healthcare Systems chapters, as system organization and improvement is intrinsic to these subjects.

The introductory paragraph provides background information and describes how the chapter remains relevant to the current practice of hospital medicine. Individual competency-based objectives outline a relevant concept and expected level of proficiency as defined by Bloom’s taxonomy.¹⁰ New objectives reflect changes in the healthcare landscape over the past decade or further enhance each chapter’s concepts. Chapter authors made an effort to develop chapter and learning objective concepts that are consistent with external resources such as the ACGME Milestones Project and practice guideline objectives developed by a variety of professional organizations.

The Core Competencies document serves as a resource for hospitalists and hospital medicine programs to evaluate, develop, and improve individual and collective skills and the practice environment. The Core Competencies also provide a framework for medical school clerkship directors and residency and fellowship program directors, as well as course directors of Continuing Medical Education programs, to develop curricula to enhance educational experiences for trainees and hospital medicine providers. The updates in every chapter in this revision to the Core Competencies reflects the changes in the healthcare landscape and hospitalist practice environment over the past decade, and we encourage readers to revisit the entire compendium. Table 3 highlights some of the salient changes in this revision.

Hospital medicine continues to evolve as a specialty. The Core Competencies define hospitalists as agents of change and foster the development of a culture of safe and effective patient care within the hospital environment. Although the CCTF hopes that the Core Competencies will preserve their relevance over time, it recognizes the importance of their periodic reevaluation and adaptation. Additionally, SHM developed the Core Competencies primarily for physicians practicing as hospitalists. As the number of physician assistants and nurse practitioners engaged in the practice of hospital medicine increases, and hospital medicine expands into nontraditional specialties such as surgical comanagement, it may be necessary to consider the development of additional or separate Hospital Medicine Core Competencies tailored to the needs of these subsets of clinicians.

Acknowledgments

The authors and the CCTF are immensely grateful to Nick Marzano for project coordination and Abbie Young for her assistance with medical editing and chapter formatting. We extend our sincerest appreciation and gratitude to the index team of authors and editors whose efforts laid the foundation for this body of work. The initial development and this revision of the Core Competencies would not have been possible without the support and assistance of the SHM staff, the SHM Education Committee, and the scores of contributors and reviewers who participated in its creation (complete list of individuals is available in Appendix 2). We thank everyone for his or her invaluable input and effort.

Disclosures

The Society of Hospital Medicine (SHM) provided administrative support for project coordination. SHM, or any of its representatives, had no role in the development of topic areas, refinement, or vetting of the topic list. No member of the Core Competencies Task Force or the SHM Education Committee received compensation for their participation in revising the Core Competencies. The authors report no conflicts of interest.

The authors would like to make the following corrections to their manuscript, Cardiac Troponins in Low-Risk Pulmonary Embolism Patients: A Systematic Review and Meta-Analysis (doi: 10.12788/jhm.2961), published online first April 25, 2018 (all corrections in bold):

• The last sentence of the results section in the abstract should read: The pooled likelihood ratios (LRs) for all-cause mortality were positive LR 2.04 [95% CI, 1.53 to 2.72] and negative LR 0.72 [95% CI, 0.37 to 1.40].  
• In the "All studies pooled" of the last row of Table 2, Tn+ is corrected to 463. See revised table below.
• On page E5, the first paragraph in the "Outcomes of Studies with Corresponding Troponin+ and Troponin-" section beginning with the fifth sentence should read as follows):

"In the pooled data, 463 (67%) patients tested negative for troponin and 228 (33%) tested positive. The overall mortality (from sensitivity analysis) including in-hospital, 30-day, and 90-day mortalities was 1.2%. The NPVs for all individual studies and the overall NPV are 1 or approximately 1. The overall PPVs and by study were low, ranging from 0 to 0.60. The PLRs and NLRs were not estimated for an outcome within an individual study if none of the patients experienced the outcome. When outcomes were only observed among troponin-negative patients, such as in the study of Moore (2009) who used 30-day all-cause mortality, the PLR had a value of zero. When outcomes were only observed among troponin-positive patients, as for 30-day all-cause mortality in the Hakemi9(2015), Lauque10 (2014), and Lankeit16 (2011) studies, the NLR had a value of zero. For zero cells, a continuity correction of 0.5 was applied. The pooled likelihood ratios (LRs) for all-cause mortality were positive LR 2.04 [95% CI, 1.53 to 2.72] and negative LR 0.72 [95% CI, 0.37 to 1.40]. The OR for all-cause mortality was 4.79 [95% CI 1.11 to 20.68, P = .0357].

The authors would like to make the following corrections to their manuscript, Cardiac Troponins in Low-Risk Pulmonary Embolism Patients: A Systematic Review and Meta-Analysis (doi: 10.12788/jhm.2961), published online first April 25, 2018 (all corrections in bold):

• The last sentence of the results section in the abstract should read: The pooled likelihood ratios (LRs) for all-cause mortality were positive LR 2.04 [95% CI, 1.53 to 2.72] and negative LR 0.72 [95% CI, 0.37 to 1.40].  
• In the "All studies pooled" of the last row of Table 2, Tn+ is corrected to 463. See revised table below.
• On page E5, the first paragraph in the "Outcomes of Studies with Corresponding Troponin+ and Troponin-" section beginning with the fifth sentence should read as follows):

"In the pooled data, 463 (67%) patients tested negative for troponin and 228 (33%) tested positive. The overall mortality (from sensitivity analysis) including in-hospital, 30-day, and 90-day mortalities was 1.2%. The NPVs for all individual studies and the overall NPV are 1 or approximately 1. The overall PPVs and by study were low, ranging from 0 to 0.60. The PLRs and NLRs were not estimated for an outcome within an individual study if none of the patients experienced the outcome. When outcomes were only observed among troponin-negative patients, such as in the study of Moore (2009) who used 30-day all-cause mortality, the PLR had a value of zero. When outcomes were only observed among troponin-positive patients, as for 30-day all-cause mortality in the Hakemi9(2015), Lauque10 (2014), and Lankeit16 (2011) studies, the NLR had a value of zero. For zero cells, a continuity correction of 0.5 was applied. The pooled likelihood ratios (LRs) for all-cause mortality were positive LR 2.04 [95% CI, 1.53 to 2.72] and negative LR 0.72 [95% CI, 0.37 to 1.40]. The OR for all-cause mortality was 4.79 [95% CI 1.11 to 20.68, P = .0357].

The authors would like to make the following corrections to their manuscript, Cardiac Troponins in Low-Risk Pulmonary Embolism Patients: A Systematic Review and Meta-Analysis (doi: 10.12788/jhm.2961), published online first April 25, 2018 (all corrections in bold):

• The last sentence of the results section in the abstract should read: The pooled likelihood ratios (LRs) for all-cause mortality were positive LR 2.04 [95% CI, 1.53 to 2.72] and negative LR 0.72 [95% CI, 0.37 to 1.40].  
• In the "All studies pooled" of the last row of Table 2, Tn+ is corrected to 463. See revised table below.
• On page E5, the first paragraph in the "Outcomes of Studies with Corresponding Troponin+ and Troponin-" section beginning with the fifth sentence should read as follows):

"In the pooled data, 463 (67%) patients tested negative for troponin and 228 (33%) tested positive. The overall mortality (from sensitivity analysis) including in-hospital, 30-day, and 90-day mortalities was 1.2%. The NPVs for all individual studies and the overall NPV are 1 or approximately 1. The overall PPVs and by study were low, ranging from 0 to 0.60. The PLRs and NLRs were not estimated for an outcome within an individual study if none of the patients experienced the outcome. When outcomes were only observed among troponin-negative patients, such as in the study of Moore (2009) who used 30-day all-cause mortality, the PLR had a value of zero. When outcomes were only observed among troponin-positive patients, as for 30-day all-cause mortality in the Hakemi9(2015), Lauque10 (2014), and Lankeit16 (2011) studies, the NLR had a value of zero. For zero cells, a continuity correction of 0.5 was applied. The pooled likelihood ratios (LRs) for all-cause mortality were positive LR 2.04 [95% CI, 1.53 to 2.72] and negative LR 0.72 [95% CI, 0.37 to 1.40]. The OR for all-cause mortality was 4.79 [95% CI 1.11 to 20.68, P = .0357].

Researchers from RAND Corp. compared performance between each VA facility and 3 corresponding non-VA settings with similar geographic settings, size, and complexity of care, using recent data on patient safety, mortality and readmission, inpatient and outpatient effectiveness, and patient-centered care.

VA hospitals performed on average the same as or significantly better than the non-VA hospitals on all 6 measures of inpatient safety, all 3 inpatient mortality measures, and 12 inpatient effectiveness measures. VA facilities also performed significantly better than commercial HMOs and Medicaid HMOs for all 16 outpatient effectiveness measures. Compared with Medicare HMOs, the VA did significantly better on 14 measures and did not differ on 2.

However, the VA performance was worse than the non-VA hospitals on 3 readmission measures and 2 effectiveness measures. For example, VA inpatient performance was significantly lower on the patient experience measure for pain management.

The researchers saw “high variation” across VA facilities in performance on some quality measures, although they note that variation was even greater among non-VA hospitals. “The variation among VA health facilities shows that veterans in some areas are not receiving the same high-quality care that other VA facilities are able to provide,” said Carrie Farmer, a co-author of the study.

Researchers from RAND Corp. compared performance between each VA facility and 3 corresponding non-VA settings with similar geographic settings, size, and complexity of care, using recent data on patient safety, mortality and readmission, inpatient and outpatient effectiveness, and patient-centered care.

VA hospitals performed on average the same as or significantly better than the non-VA hospitals on all 6 measures of inpatient safety, all 3 inpatient mortality measures, and 12 inpatient effectiveness measures. VA facilities also performed significantly better than commercial HMOs and Medicaid HMOs for all 16 outpatient effectiveness measures. Compared with Medicare HMOs, the VA did significantly better on 14 measures and did not differ on 2.

However, the VA performance was worse than the non-VA hospitals on 3 readmission measures and 2 effectiveness measures. For example, VA inpatient performance was significantly lower on the patient experience measure for pain management.

The researchers saw “high variation” across VA facilities in performance on some quality measures, although they note that variation was even greater among non-VA hospitals. “The variation among VA health facilities shows that veterans in some areas are not receiving the same high-quality care that other VA facilities are able to provide,” said Carrie Farmer, a co-author of the study.

Researchers from RAND Corp. compared performance between each VA facility and 3 corresponding non-VA settings with similar geographic settings, size, and complexity of care, using recent data on patient safety, mortality and readmission, inpatient and outpatient effectiveness, and patient-centered care.

VA hospitals performed on average the same as or significantly better than the non-VA hospitals on all 6 measures of inpatient safety, all 3 inpatient mortality measures, and 12 inpatient effectiveness measures. VA facilities also performed significantly better than commercial HMOs and Medicaid HMOs for all 16 outpatient effectiveness measures. Compared with Medicare HMOs, the VA did significantly better on 14 measures and did not differ on 2.

However, the VA performance was worse than the non-VA hospitals on 3 readmission measures and 2 effectiveness measures. For example, VA inpatient performance was significantly lower on the patient experience measure for pain management.

The researchers saw “high variation” across VA facilities in performance on some quality measures, although they note that variation was even greater among non-VA hospitals. “The variation among VA health facilities shows that veterans in some areas are not receiving the same high-quality care that other VA facilities are able to provide,” said Carrie Farmer, a co-author of the study.

To ensure hospital quality, the Centers for Medicaid & Medicare Services have tied payments to performance measures, including readmissions.¹ One readmission metric, the Potentially Preventable Readmission measure (3M, PPR), was initially developed for Medicare and defined as readmissions related to an index admission, excluding those for treatment of cancer, related to trauma or burns, or following neonatal hospitalization. The PPR includes readmissions for both primary mental health conditions (MHCs) and for other hospitalizations with comorbid MHCs.² Although controversies surround equating a hospital’s quality with its rate of readmissions, the PPR has been expanded to include numerous states. Since the PPR is also used for the Medicaid population in these states, it also measures pediatric readmissions. Hospitals in states adopting PPR calculations, including children’s hospitals, must either meet these new quality metrics or risk financial penalties. In light of evidence of high readmission rates among adult patients with MHCs, several states have modified the PPR to exclude MHCs and claims for mental health services.^3–9

In their study, “Mental Health Conditions and Unplanned Hospital Readmissions in Children,” Doupnik et al. provided compelling evidence that MHCs in children (similar to adults) are closely associated with readmissions.¹⁰ MHCs are possibly underappreciated risk factors for readmission penalties and therefore represent a necessary point for increased awareness. Doupnik et al. calculated 30-day unplanned hospital readmissions of children with versus without comorbid MHCs using another standard measure, the Pediatric All-Condition Readmission (PACR) measure. The PACR measure excludes index admissions with a MHC as primary diagnosis but includes children with comorbid MHCs.

Doupnik et al. used a nationally representative cohort of all index hospitalizations of children aged 3–21 years from the 2013 Nationwide Readmission Database that allowed for estimates of MHC prevalence in the study population.¹¹ A comorbid MHC was identified in almost 1 in 5 medical admissions and 1 in 7 procedural admissions. Comorbid substance abuse was identified in 5.4% of medical admissions and 4.7% of procedure admissions, making this diagnosis the most frequently coded stand-alone MHC. The authors’ findings are particularly noteworthy given that diagnosis of MHCs is highly dependent upon coding and is therefore almost certainly underreported. In pediatric inpatient populations, the true prevalence of comorbid MHCs is probably higher.

Doupnik et al. observed that comorbid MHCs are a significant risk factor for readmission. After adjustment for demographic, clinical, and hospital characteristics, children with MHCs presented a nearly 25% higher chance of readmission for both medical and procedural hospitalizations. Children admitted with medical conditions and multiple MHCs yielded odds of readmission 50% higher than that of children without MHCs. Overall, the presence of MHCs was associated with more than 2,500 medical and 200 procedure readmissions.

Previous studies in adult populations have also found that comorbid MHCs are an important risk factor for readmissions.^12,13 Other research describes that children with MHCs have increased hospital resource use, including longer lengths of stay and higher hospitalization costs.^14-17 Further, children with MHCs as a primary diagnosis are more prone to readmission, with readmission rates approaching those observed in children with medical complexity in some cases.^18,19 MHCs are common among hospitalized children and have become an increasingly present comorbidity in primary medical or surgical admissions.¹⁷

One particular strength of this study lies in its description of the relationship between comorbid (not primary) MHCs and readmission following medical or surgical procedures in hospitalized children. This relationship has been examined in adult inpatient populations but less so in pediatric inpatient populations.^12,13 This study provides insights into the relationships between specific MHCs and unplanned readmissions for certain primary medical or surgical diagnoses, including those for attention deficit disorder and autism that are not well-recognized in adult populations.

High-quality inpatient pediatric practice depends not only upon recognition of concurrent MHCs during hospitalizations but also assurance of follow-up outside of such institutions. During the inpatient care of children, pediatric hospitalists often perform myopic inpatient care which fails to routinely address underlying MHCs.²⁰ For example, among children who are admitted with primary medical or procedure diagnoses, it is possible, or perhaps likely, that providers give little attention to an underlying MHC outside of continuation of a current medication. Comorbid MHCs are not accounted for within readmission calculations that directly affect hospital reimbursement. This study suggests that comorbid MHCs in hospitalized children may worsen readmission penalty status. In this manner, comorbid MHCs may represent a hospital’s blindside.

We agree with Doupnik et al. that an integrated approach with medical and mental health professionals may improve the care of children with MHCs in hospitalized settings. This improvement in care may eventually affect hospital-level national quality metrics, such as readmissions. The findings of Doupnik et al. also provide a strong argument that pediatric inpatient providers should consider mental health consultations for patients with frequent admissions associated with chronic conditions, as comorbid MHCs are associated with worsened disease states and account for a disproportionate share of admissions for children with chronic conditions.^21,22 Recognition of comorbid MHCs may improve baseline chronic disease states for hospitalized children.

We assert that the current silos in inpatient pediatrics of medical and mental healthcare are outdated. Pediatric hospitalists need to assess for and access effective MHC treatment options in the inpatient setting. In addition to the provision of mental health care within hospital settings, providers should also ensure that appropriate follow-up is arranged at the time of discharge. From a health policy standpoint, providers should clarify how both primary and comorbid MHCs are included within readmission measures while considering the close association of these conditions with readmission. Although the care of children with MHCs requires a long-term and coordinated approach, identification and treatment during hospitalization offer unique opportunities to modify outcomes of MHCs and coexistent medical and surgical diagnoses.

Disclosures

The authors declare no conflict of interest.

To ensure hospital quality, the Centers for Medicaid & Medicare Services have tied payments to performance measures, including readmissions.¹ One readmission metric, the Potentially Preventable Readmission measure (3M, PPR), was initially developed for Medicare and defined as readmissions related to an index admission, excluding those for treatment of cancer, related to trauma or burns, or following neonatal hospitalization. The PPR includes readmissions for both primary mental health conditions (MHCs) and for other hospitalizations with comorbid MHCs.² Although controversies surround equating a hospital’s quality with its rate of readmissions, the PPR has been expanded to include numerous states. Since the PPR is also used for the Medicaid population in these states, it also measures pediatric readmissions. Hospitals in states adopting PPR calculations, including children’s hospitals, must either meet these new quality metrics or risk financial penalties. In light of evidence of high readmission rates among adult patients with MHCs, several states have modified the PPR to exclude MHCs and claims for mental health services.^3–9

In their study, “Mental Health Conditions and Unplanned Hospital Readmissions in Children,” Doupnik et al. provided compelling evidence that MHCs in children (similar to adults) are closely associated with readmissions.¹⁰ MHCs are possibly underappreciated risk factors for readmission penalties and therefore represent a necessary point for increased awareness. Doupnik et al. calculated 30-day unplanned hospital readmissions of children with versus without comorbid MHCs using another standard measure, the Pediatric All-Condition Readmission (PACR) measure. The PACR measure excludes index admissions with a MHC as primary diagnosis but includes children with comorbid MHCs.

Doupnik et al. used a nationally representative cohort of all index hospitalizations of children aged 3–21 years from the 2013 Nationwide Readmission Database that allowed for estimates of MHC prevalence in the study population.¹¹ A comorbid MHC was identified in almost 1 in 5 medical admissions and 1 in 7 procedural admissions. Comorbid substance abuse was identified in 5.4% of medical admissions and 4.7% of procedure admissions, making this diagnosis the most frequently coded stand-alone MHC. The authors’ findings are particularly noteworthy given that diagnosis of MHCs is highly dependent upon coding and is therefore almost certainly underreported. In pediatric inpatient populations, the true prevalence of comorbid MHCs is probably higher.

Doupnik et al. observed that comorbid MHCs are a significant risk factor for readmission. After adjustment for demographic, clinical, and hospital characteristics, children with MHCs presented a nearly 25% higher chance of readmission for both medical and procedural hospitalizations. Children admitted with medical conditions and multiple MHCs yielded odds of readmission 50% higher than that of children without MHCs. Overall, the presence of MHCs was associated with more than 2,500 medical and 200 procedure readmissions.

Previous studies in adult populations have also found that comorbid MHCs are an important risk factor for readmissions.^12,13 Other research describes that children with MHCs have increased hospital resource use, including longer lengths of stay and higher hospitalization costs.^14-17 Further, children with MHCs as a primary diagnosis are more prone to readmission, with readmission rates approaching those observed in children with medical complexity in some cases.^18,19 MHCs are common among hospitalized children and have become an increasingly present comorbidity in primary medical or surgical admissions.¹⁷

One particular strength of this study lies in its description of the relationship between comorbid (not primary) MHCs and readmission following medical or surgical procedures in hospitalized children. This relationship has been examined in adult inpatient populations but less so in pediatric inpatient populations.^12,13 This study provides insights into the relationships between specific MHCs and unplanned readmissions for certain primary medical or surgical diagnoses, including those for attention deficit disorder and autism that are not well-recognized in adult populations.

High-quality inpatient pediatric practice depends not only upon recognition of concurrent MHCs during hospitalizations but also assurance of follow-up outside of such institutions. During the inpatient care of children, pediatric hospitalists often perform myopic inpatient care which fails to routinely address underlying MHCs.²⁰ For example, among children who are admitted with primary medical or procedure diagnoses, it is possible, or perhaps likely, that providers give little attention to an underlying MHC outside of continuation of a current medication. Comorbid MHCs are not accounted for within readmission calculations that directly affect hospital reimbursement. This study suggests that comorbid MHCs in hospitalized children may worsen readmission penalty status. In this manner, comorbid MHCs may represent a hospital’s blindside.

We agree with Doupnik et al. that an integrated approach with medical and mental health professionals may improve the care of children with MHCs in hospitalized settings. This improvement in care may eventually affect hospital-level national quality metrics, such as readmissions. The findings of Doupnik et al. also provide a strong argument that pediatric inpatient providers should consider mental health consultations for patients with frequent admissions associated with chronic conditions, as comorbid MHCs are associated with worsened disease states and account for a disproportionate share of admissions for children with chronic conditions.^21,22 Recognition of comorbid MHCs may improve baseline chronic disease states for hospitalized children.

We assert that the current silos in inpatient pediatrics of medical and mental healthcare are outdated. Pediatric hospitalists need to assess for and access effective MHC treatment options in the inpatient setting. In addition to the provision of mental health care within hospital settings, providers should also ensure that appropriate follow-up is arranged at the time of discharge. From a health policy standpoint, providers should clarify how both primary and comorbid MHCs are included within readmission measures while considering the close association of these conditions with readmission. Although the care of children with MHCs requires a long-term and coordinated approach, identification and treatment during hospitalization offer unique opportunities to modify outcomes of MHCs and coexistent medical and surgical diagnoses.

Disclosures

The authors declare no conflict of interest.

To ensure hospital quality, the Centers for Medicaid & Medicare Services have tied payments to performance measures, including readmissions.¹ One readmission metric, the Potentially Preventable Readmission measure (3M, PPR), was initially developed for Medicare and defined as readmissions related to an index admission, excluding those for treatment of cancer, related to trauma or burns, or following neonatal hospitalization. The PPR includes readmissions for both primary mental health conditions (MHCs) and for other hospitalizations with comorbid MHCs.² Although controversies surround equating a hospital’s quality with its rate of readmissions, the PPR has been expanded to include numerous states. Since the PPR is also used for the Medicaid population in these states, it also measures pediatric readmissions. Hospitals in states adopting PPR calculations, including children’s hospitals, must either meet these new quality metrics or risk financial penalties. In light of evidence of high readmission rates among adult patients with MHCs, several states have modified the PPR to exclude MHCs and claims for mental health services.^3–9

In their study, “Mental Health Conditions and Unplanned Hospital Readmissions in Children,” Doupnik et al. provided compelling evidence that MHCs in children (similar to adults) are closely associated with readmissions.¹⁰ MHCs are possibly underappreciated risk factors for readmission penalties and therefore represent a necessary point for increased awareness. Doupnik et al. calculated 30-day unplanned hospital readmissions of children with versus without comorbid MHCs using another standard measure, the Pediatric All-Condition Readmission (PACR) measure. The PACR measure excludes index admissions with a MHC as primary diagnosis but includes children with comorbid MHCs.

Doupnik et al. used a nationally representative cohort of all index hospitalizations of children aged 3–21 years from the 2013 Nationwide Readmission Database that allowed for estimates of MHC prevalence in the study population.¹¹ A comorbid MHC was identified in almost 1 in 5 medical admissions and 1 in 7 procedural admissions. Comorbid substance abuse was identified in 5.4% of medical admissions and 4.7% of procedure admissions, making this diagnosis the most frequently coded stand-alone MHC. The authors’ findings are particularly noteworthy given that diagnosis of MHCs is highly dependent upon coding and is therefore almost certainly underreported. In pediatric inpatient populations, the true prevalence of comorbid MHCs is probably higher.

Doupnik et al. observed that comorbid MHCs are a significant risk factor for readmission. After adjustment for demographic, clinical, and hospital characteristics, children with MHCs presented a nearly 25% higher chance of readmission for both medical and procedural hospitalizations. Children admitted with medical conditions and multiple MHCs yielded odds of readmission 50% higher than that of children without MHCs. Overall, the presence of MHCs was associated with more than 2,500 medical and 200 procedure readmissions.

Previous studies in adult populations have also found that comorbid MHCs are an important risk factor for readmissions.^12,13 Other research describes that children with MHCs have increased hospital resource use, including longer lengths of stay and higher hospitalization costs.^14-17 Further, children with MHCs as a primary diagnosis are more prone to readmission, with readmission rates approaching those observed in children with medical complexity in some cases.^18,19 MHCs are common among hospitalized children and have become an increasingly present comorbidity in primary medical or surgical admissions.¹⁷

One particular strength of this study lies in its description of the relationship between comorbid (not primary) MHCs and readmission following medical or surgical procedures in hospitalized children. This relationship has been examined in adult inpatient populations but less so in pediatric inpatient populations.^12,13 This study provides insights into the relationships between specific MHCs and unplanned readmissions for certain primary medical or surgical diagnoses, including those for attention deficit disorder and autism that are not well-recognized in adult populations.

High-quality inpatient pediatric practice depends not only upon recognition of concurrent MHCs during hospitalizations but also assurance of follow-up outside of such institutions. During the inpatient care of children, pediatric hospitalists often perform myopic inpatient care which fails to routinely address underlying MHCs.²⁰ For example, among children who are admitted with primary medical or procedure diagnoses, it is possible, or perhaps likely, that providers give little attention to an underlying MHC outside of continuation of a current medication. Comorbid MHCs are not accounted for within readmission calculations that directly affect hospital reimbursement. This study suggests that comorbid MHCs in hospitalized children may worsen readmission penalty status. In this manner, comorbid MHCs may represent a hospital’s blindside.

We agree with Doupnik et al. that an integrated approach with medical and mental health professionals may improve the care of children with MHCs in hospitalized settings. This improvement in care may eventually affect hospital-level national quality metrics, such as readmissions. The findings of Doupnik et al. also provide a strong argument that pediatric inpatient providers should consider mental health consultations for patients with frequent admissions associated with chronic conditions, as comorbid MHCs are associated with worsened disease states and account for a disproportionate share of admissions for children with chronic conditions.^21,22 Recognition of comorbid MHCs may improve baseline chronic disease states for hospitalized children.

We assert that the current silos in inpatient pediatrics of medical and mental healthcare are outdated. Pediatric hospitalists need to assess for and access effective MHC treatment options in the inpatient setting. In addition to the provision of mental health care within hospital settings, providers should also ensure that appropriate follow-up is arranged at the time of discharge. From a health policy standpoint, providers should clarify how both primary and comorbid MHCs are included within readmission measures while considering the close association of these conditions with readmission. Although the care of children with MHCs requires a long-term and coordinated approach, identification and treatment during hospitalization offer unique opportunities to modify outcomes of MHCs and coexistent medical and surgical diagnoses.

Disclosures

The authors declare no conflict of interest.