PAS Annual Meeting 2011

DENVER – Considerable variation exists in emergency department use of computed tomography or ultrasound for children with abdominal pain and appendicitis, results from a large national study demonstrated.

"Despite the greater diagnostic accuracy of CT, use of CT is decreasing for these conditions, while ultrasound use has been increasing," Michael C. Monuteaux, Sc.D., said at the annual meeting of the Pediatric Academic Societies.

Increasing use of either imaging modality was associated with negative appendectomy rates, said Dr. Monuteaux, a senior biostatistician at Children’s Hospital Boston. "As the hospital-level imaging increased, the hospital-level negative appendectomy [rate] decreased."

The findings come from an analysis of the Pediatric Health Information System, a database maintained by 40 U.S. pediatric hospitals. The researchers studied 8,959,155 visits that patients under the age of 19 years made to emergency departments between 2005 and 2009 with a primary diagnosis of appendicitis, abdominal pain, or common, nontraumatic, acute disease mimickers of appendicitis.

Of these patients, 564,595 (6%) had abdominal pain and 55,238 (0.6%) had appendicitis.

The use of CT in patients with a diagnosis of appendicitis ranged from 21% to 49%, for a median of 34%, while the use of CT for other diagnoses ranged from 5% to 9%, for a median of 6%, Dr. Monuteaux reported.

Use of ultrasound in patients with a diagnosis of appendicitis ranged from 2% to 26%, for a median of 7%, while use of ultrasound for other diagnoses ranged from 2% to 8%, for a median of 6%.

Among patients diagnosed with appendicitis, CT rates decreased from a peak of 35% in 2007 to 29% in 2009, while ultrasound rates increased from 17% in 2005 to 25% in 2009.

Among patients with other diagnoses, CT rates decreased from a peak of 35% in 2007 to 29% in 2009, while ultrasound rates increased from 17% in 2005 to 25% in 2009.

The researchers observed no correlations between rates of either imaging modality and rates of perforated appendicitis. Increasing use of either CT or ultrasound was associated with decreasing negative appendectomy rates. In fact, for every 10% decrease in imaging, there was a 6.4% decrease in negative appendectomy rates.

Dr. Monuteaux acknowledged certain limitations of the study, including the fact that the cohort was drawn from an administrative database, "so it’s difficult to infer clinical management and outcome. We [also] could not adjust for any imaging that may have been done outside of the hospital prior to transfer. We also could not control or account for external factors such as [emergency department] crowding, the surrounding primary care network, or access to care that could possibly influence imaging."

He also noted that the association between type of imaging and patient-level perforation may be related to institutional clinical practice when perforation is suspected.

Dr. Monuteaux said that he had no relevant financial conflicts to disclose.

DENVER – Considerable variation exists in emergency department use of computed tomography or ultrasound for children with abdominal pain and appendicitis, results from a large national study demonstrated.

"Despite the greater diagnostic accuracy of CT, use of CT is decreasing for these conditions, while ultrasound use has been increasing," Michael C. Monuteaux, Sc.D., said at the annual meeting of the Pediatric Academic Societies.

Increasing use of either imaging modality was associated with negative appendectomy rates, said Dr. Monuteaux, a senior biostatistician at Children’s Hospital Boston. "As the hospital-level imaging increased, the hospital-level negative appendectomy [rate] decreased."

The findings come from an analysis of the Pediatric Health Information System, a database maintained by 40 U.S. pediatric hospitals. The researchers studied 8,959,155 visits that patients under the age of 19 years made to emergency departments between 2005 and 2009 with a primary diagnosis of appendicitis, abdominal pain, or common, nontraumatic, acute disease mimickers of appendicitis.

Of these patients, 564,595 (6%) had abdominal pain and 55,238 (0.6%) had appendicitis.

The use of CT in patients with a diagnosis of appendicitis ranged from 21% to 49%, for a median of 34%, while the use of CT for other diagnoses ranged from 5% to 9%, for a median of 6%, Dr. Monuteaux reported.

Use of ultrasound in patients with a diagnosis of appendicitis ranged from 2% to 26%, for a median of 7%, while use of ultrasound for other diagnoses ranged from 2% to 8%, for a median of 6%.

Among patients diagnosed with appendicitis, CT rates decreased from a peak of 35% in 2007 to 29% in 2009, while ultrasound rates increased from 17% in 2005 to 25% in 2009.

Among patients with other diagnoses, CT rates decreased from a peak of 35% in 2007 to 29% in 2009, while ultrasound rates increased from 17% in 2005 to 25% in 2009.

The researchers observed no correlations between rates of either imaging modality and rates of perforated appendicitis. Increasing use of either CT or ultrasound was associated with decreasing negative appendectomy rates. In fact, for every 10% decrease in imaging, there was a 6.4% decrease in negative appendectomy rates.

Dr. Monuteaux acknowledged certain limitations of the study, including the fact that the cohort was drawn from an administrative database, "so it’s difficult to infer clinical management and outcome. We [also] could not adjust for any imaging that may have been done outside of the hospital prior to transfer. We also could not control or account for external factors such as [emergency department] crowding, the surrounding primary care network, or access to care that could possibly influence imaging."

He also noted that the association between type of imaging and patient-level perforation may be related to institutional clinical practice when perforation is suspected.

Dr. Monuteaux said that he had no relevant financial conflicts to disclose.

DENVER – Considerable variation exists in emergency department use of computed tomography or ultrasound for children with abdominal pain and appendicitis, results from a large national study demonstrated.

"Despite the greater diagnostic accuracy of CT, use of CT is decreasing for these conditions, while ultrasound use has been increasing," Michael C. Monuteaux, Sc.D., said at the annual meeting of the Pediatric Academic Societies.

Increasing use of either imaging modality was associated with negative appendectomy rates, said Dr. Monuteaux, a senior biostatistician at Children’s Hospital Boston. "As the hospital-level imaging increased, the hospital-level negative appendectomy [rate] decreased."

The findings come from an analysis of the Pediatric Health Information System, a database maintained by 40 U.S. pediatric hospitals. The researchers studied 8,959,155 visits that patients under the age of 19 years made to emergency departments between 2005 and 2009 with a primary diagnosis of appendicitis, abdominal pain, or common, nontraumatic, acute disease mimickers of appendicitis.

Of these patients, 564,595 (6%) had abdominal pain and 55,238 (0.6%) had appendicitis.

The use of CT in patients with a diagnosis of appendicitis ranged from 21% to 49%, for a median of 34%, while the use of CT for other diagnoses ranged from 5% to 9%, for a median of 6%, Dr. Monuteaux reported.

Use of ultrasound in patients with a diagnosis of appendicitis ranged from 2% to 26%, for a median of 7%, while use of ultrasound for other diagnoses ranged from 2% to 8%, for a median of 6%.

Among patients diagnosed with appendicitis, CT rates decreased from a peak of 35% in 2007 to 29% in 2009, while ultrasound rates increased from 17% in 2005 to 25% in 2009.

Among patients with other diagnoses, CT rates decreased from a peak of 35% in 2007 to 29% in 2009, while ultrasound rates increased from 17% in 2005 to 25% in 2009.

The researchers observed no correlations between rates of either imaging modality and rates of perforated appendicitis. Increasing use of either CT or ultrasound was associated with decreasing negative appendectomy rates. In fact, for every 10% decrease in imaging, there was a 6.4% decrease in negative appendectomy rates.

Dr. Monuteaux acknowledged certain limitations of the study, including the fact that the cohort was drawn from an administrative database, "so it’s difficult to infer clinical management and outcome. We [also] could not adjust for any imaging that may have been done outside of the hospital prior to transfer. We also could not control or account for external factors such as [emergency department] crowding, the surrounding primary care network, or access to care that could possibly influence imaging."

He also noted that the association between type of imaging and patient-level perforation may be related to institutional clinical practice when perforation is suspected.

Dr. Monuteaux said that he had no relevant financial conflicts to disclose.

DENVER – Considerable variation exists in emergency department use of computed tomography or ultrasound for children with abdominal pain and appendicitis, results from a large national study demonstrated.

"Despite the greater diagnostic accuracy of CT, use of CT is decreasing for these conditions, while ultrasound use has been increasing," Michael C. Monuteaux, Sc.D., said at the annual meeting of the Pediatric Academic Societies.

Increasing use of either imaging modality was associated with negative appendectomy rates, said Dr. Monuteaux, a senior biostatistician at Children’s Hospital Boston. "As the hospital-level imaging increased, the hospital-level negative appendectomy [rate] decreased."

The findings come from an analysis of the Pediatric Health Information System, a database maintained by 40 U.S. pediatric hospitals. The researchers studied 8,959,155 visits that patients under the age of 19 years made to emergency departments between 2005 and 2009 with a primary diagnosis of appendicitis, abdominal pain, or common, nontraumatic, acute disease mimickers of appendicitis.

Of these patients, 564,595 (6%) had abdominal pain and 55,238 (0.6%) had appendicitis.

The use of CT in patients with a diagnosis of appendicitis ranged from 21% to 49%, for a median of 34%, while the use of CT for other diagnoses ranged from 5% to 9%, for a median of 6%, Dr. Monuteaux reported.

Use of ultrasound in patients with a diagnosis of appendicitis ranged from 2% to 26%, for a median of 7%, while use of ultrasound for other diagnoses ranged from 2% to 8%, for a median of 6%.

Among patients diagnosed with appendicitis, CT rates decreased from a peak of 35% in 2007 to 29% in 2009, while ultrasound rates increased from 17% in 2005 to 25% in 2009.

Among patients with other diagnoses, CT rates decreased from a peak of 35% in 2007 to 29% in 2009, while ultrasound rates increased from 17% in 2005 to 25% in 2009.

The researchers observed no correlations between rates of either imaging modality and rates of perforated appendicitis. Increasing use of either CT or ultrasound was associated with decreasing negative appendectomy rates. In fact, for every 10% decrease in imaging, there was a 6.4% decrease in negative appendectomy rates.

Dr. Monuteaux acknowledged certain limitations of the study, including the fact that the cohort was drawn from an administrative database, "so it’s difficult to infer clinical management and outcome. We [also] could not adjust for any imaging that may have been done outside of the hospital prior to transfer. We also could not control or account for external factors such as [emergency department] crowding, the surrounding primary care network, or access to care that could possibly influence imaging."

He also noted that the association between type of imaging and patient-level perforation may be related to institutional clinical practice when perforation is suspected.

Dr. Monuteaux said that he had no relevant financial conflicts to disclose.

DENVER – Considerable variation exists in emergency department use of computed tomography or ultrasound for children with abdominal pain and appendicitis, results from a large national study demonstrated.

"Despite the greater diagnostic accuracy of CT, use of CT is decreasing for these conditions, while ultrasound use has been increasing," Michael C. Monuteaux, Sc.D., said at the annual meeting of the Pediatric Academic Societies.

Increasing use of either imaging modality was associated with negative appendectomy rates, said Dr. Monuteaux, a senior biostatistician at Children’s Hospital Boston. "As the hospital-level imaging increased, the hospital-level negative appendectomy [rate] decreased."

The findings come from an analysis of the Pediatric Health Information System, a database maintained by 40 U.S. pediatric hospitals. The researchers studied 8,959,155 visits that patients under the age of 19 years made to emergency departments between 2005 and 2009 with a primary diagnosis of appendicitis, abdominal pain, or common, nontraumatic, acute disease mimickers of appendicitis.

Of these patients, 564,595 (6%) had abdominal pain and 55,238 (0.6%) had appendicitis.

The use of CT in patients with a diagnosis of appendicitis ranged from 21% to 49%, for a median of 34%, while the use of CT for other diagnoses ranged from 5% to 9%, for a median of 6%, Dr. Monuteaux reported.

Use of ultrasound in patients with a diagnosis of appendicitis ranged from 2% to 26%, for a median of 7%, while use of ultrasound for other diagnoses ranged from 2% to 8%, for a median of 6%.

Among patients diagnosed with appendicitis, CT rates decreased from a peak of 35% in 2007 to 29% in 2009, while ultrasound rates increased from 17% in 2005 to 25% in 2009.

Among patients with other diagnoses, CT rates decreased from a peak of 35% in 2007 to 29% in 2009, while ultrasound rates increased from 17% in 2005 to 25% in 2009.

The researchers observed no correlations between rates of either imaging modality and rates of perforated appendicitis. Increasing use of either CT or ultrasound was associated with decreasing negative appendectomy rates. In fact, for every 10% decrease in imaging, there was a 6.4% decrease in negative appendectomy rates.

Dr. Monuteaux acknowledged certain limitations of the study, including the fact that the cohort was drawn from an administrative database, "so it’s difficult to infer clinical management and outcome. We [also] could not adjust for any imaging that may have been done outside of the hospital prior to transfer. We also could not control or account for external factors such as [emergency department] crowding, the surrounding primary care network, or access to care that could possibly influence imaging."

He also noted that the association between type of imaging and patient-level perforation may be related to institutional clinical practice when perforation is suspected.

Dr. Monuteaux said that he had no relevant financial conflicts to disclose.

DENVER – Considerable variation exists in emergency department use of computed tomography or ultrasound for children with abdominal pain and appendicitis, results from a large national study demonstrated.

"Despite the greater diagnostic accuracy of CT, use of CT is decreasing for these conditions, while ultrasound use has been increasing," Michael C. Monuteaux, Sc.D., said at the annual meeting of the Pediatric Academic Societies.

Increasing use of either imaging modality was associated with negative appendectomy rates, said Dr. Monuteaux, a senior biostatistician at Children’s Hospital Boston. "As the hospital-level imaging increased, the hospital-level negative appendectomy [rate] decreased."

The findings come from an analysis of the Pediatric Health Information System, a database maintained by 40 U.S. pediatric hospitals. The researchers studied 8,959,155 visits that patients under the age of 19 years made to emergency departments between 2005 and 2009 with a primary diagnosis of appendicitis, abdominal pain, or common, nontraumatic, acute disease mimickers of appendicitis.

Of these patients, 564,595 (6%) had abdominal pain and 55,238 (0.6%) had appendicitis.

The use of CT in patients with a diagnosis of appendicitis ranged from 21% to 49%, for a median of 34%, while the use of CT for other diagnoses ranged from 5% to 9%, for a median of 6%, Dr. Monuteaux reported.

Use of ultrasound in patients with a diagnosis of appendicitis ranged from 2% to 26%, for a median of 7%, while use of ultrasound for other diagnoses ranged from 2% to 8%, for a median of 6%.

Among patients diagnosed with appendicitis, CT rates decreased from a peak of 35% in 2007 to 29% in 2009, while ultrasound rates increased from 17% in 2005 to 25% in 2009.

Among patients with other diagnoses, CT rates decreased from a peak of 35% in 2007 to 29% in 2009, while ultrasound rates increased from 17% in 2005 to 25% in 2009.

The researchers observed no correlations between rates of either imaging modality and rates of perforated appendicitis. Increasing use of either CT or ultrasound was associated with decreasing negative appendectomy rates. In fact, for every 10% decrease in imaging, there was a 6.4% decrease in negative appendectomy rates.

Dr. Monuteaux acknowledged certain limitations of the study, including the fact that the cohort was drawn from an administrative database, "so it’s difficult to infer clinical management and outcome. We [also] could not adjust for any imaging that may have been done outside of the hospital prior to transfer. We also could not control or account for external factors such as [emergency department] crowding, the surrounding primary care network, or access to care that could possibly influence imaging."

He also noted that the association between type of imaging and patient-level perforation may be related to institutional clinical practice when perforation is suspected.

Dr. Monuteaux said that he had no relevant financial conflicts to disclose.

DENVER – Children exposed to secondhand tobacco smoke who are admitted to the hospital for influenza are more likely to require admission to the intensive care unit and have a longer hospital stay than their peers who are not exposed to secondhand smoke.

These effects are even greater for children with chronic illnesses who are exposed to secondhand smoke, Dr. Karen M. Wilson reported at the annual meeting of the Pediatric Academic Societies.

An estimated 18% of children aged 3-11 years are regularly exposed to secondhand tobacco smoke inside the home, said Dr. Wilson, assistant professor of pediatrics at the University of Rochester (N.Y.).

Although secondhand smoke exposure is associated with worse outcomes for children’s illnesses, including respiratory syncytial virus and asthma, "the effect of secondhand smoke exposure on influenza severity in children is unclear," she noted. "More than 40% of preschool children experience influenza at some point. In adults, tobacco smoke increases the risk of influenza infection and the risk of complications."

To determine if children hospitalized with influenza who are exposed to secondhand smoke have more severe illness, Dr. Wilson and her associates conducted a review of 169 medical charts at Golisano Children’s Hospital in Rochester. They generated a list of patients aged 0-15 years with a discharge diagnosis of influenza between 2002 and 2009. The influenza diagnosis was verified by laboratory review.

Measures of severity included intensive care unit admission, defined as admission or transfer to the ICU at any time during the stay; need for mechanical ventilation, defined as any documentation of endotracheal intubation during the stay; and length of stay.

Exposure to secondhand smoke was assessed by any documentation of presence or absence of secondhand smoke exposure by any provider. "Any documentation of exposure was considered exposed; documentation of no exposure was considered not exposed," Dr. Wilson said.

She reported findings from 113 children who were included in the final analysis. Of these, 46 (41%) were exposed to secondhand smoke and 67 (59%) were not. The average age of the 113 children was 4 years, and 50% were male. Of the 113 children, 58% were white, 22% were black, 8% were Hispanic, and 3.5% were Asian; race/ethnicity was unknown in the remaining 8.5%. Fewer than half of the children (44%) had public health insurance.

More than three-quarters of the children (78%) had influenza A. In addition, 25% had asthma, 25% had an underlying chronic condition, 14% had documentation of prematurity, 19% required ICU care, and 6% required mechanical ventilation.

None of the potential covariates – including asthma, prematurity, and chronic conditions – were significantly associated with secondhand smoke exposure. However, children exposed to secondhand smoke were significantly more likely to require ICU admission (31% vs. 10% for children with no exposure) and mechanical ventilation (13% vs. 2%, respectively).

The mean length of stay was 2.1 days for children who had no chronic condition or exposure to secondhand smoke, 2.5 days for children who had no chronic condition but had exposure to secondhand smoke, 3.5 days for children who had a chronic condition but no exposure to secondhand smoke, and 11 days for children who had a chronic condition and were exposed to secondhand smoke.

In a logistic regression model controlling for age, gender, race, and type of insurance, exposure to secondhand smoke was significantly associated with ICU admission but chronic conditions were not.

In a logistic regression model limited to exposure to secondhand smoke and chronic conditions, chronic conditions were associated with the need for mechanical ventilation but exposure to secondhand smoke was not.

In a negative binomial regression model using the log-transformed length of stay, controlling for age, gender, race, insurance type, and chronic conditions, exposure to secondhand smoke was associated with an increased length of hospital stay, with an incident rate ratio of 1.9.

Dr. Wilson acknowledged certain limitations of the study, including its single-center design "and the potential for errors in documentation and abstraction," she said. "The exposure measure was reliant on provider documentation ... but provider documentation is more likely to underestimate secondhand smoke exposure in children, so we probably misclassified some children as being non–smoke exposed."

In addition, "there may be other covariates that we were not able to measure because we don’t have documentation in the chart," she said.

Despite such limitations, Dr. Wilson said that the findings support the notion of considering secondhand smoke exposure in risk stratification for children admitted with influenza. "Greater efforts are needed to help parents eliminate their children’s exposure to secondhand smoke," she said. "Parents of children with chronic illness should be aware of the risk of secondhand smoke exposure, and children exposed to secondhand smoke should be a priority group for influenza immunization."

Dr. Wilson disclosed that she is on the speakers bureau for the American Academy of Pediatrics Julius B. Richmond Center of Excellence, with funding from the Flight Attendant Medical Research Institute, National Research Service Award T32, Strong Children’s Research Center Summer Research Program, and the Child Health Corporation of America through a grant to the Pediatric Research in Inpatient Settings Network.

DENVER – Children exposed to secondhand tobacco smoke who are admitted to the hospital for influenza are more likely to require admission to the intensive care unit and have a longer hospital stay than their peers who are not exposed to secondhand smoke.

These effects are even greater for children with chronic illnesses who are exposed to secondhand smoke, Dr. Karen M. Wilson reported at the annual meeting of the Pediatric Academic Societies.

An estimated 18% of children aged 3-11 years are regularly exposed to secondhand tobacco smoke inside the home, said Dr. Wilson, assistant professor of pediatrics at the University of Rochester (N.Y.).

Although secondhand smoke exposure is associated with worse outcomes for children’s illnesses, including respiratory syncytial virus and asthma, "the effect of secondhand smoke exposure on influenza severity in children is unclear," she noted. "More than 40% of preschool children experience influenza at some point. In adults, tobacco smoke increases the risk of influenza infection and the risk of complications."

To determine if children hospitalized with influenza who are exposed to secondhand smoke have more severe illness, Dr. Wilson and her associates conducted a review of 169 medical charts at Golisano Children’s Hospital in Rochester. They generated a list of patients aged 0-15 years with a discharge diagnosis of influenza between 2002 and 2009. The influenza diagnosis was verified by laboratory review.

Measures of severity included intensive care unit admission, defined as admission or transfer to the ICU at any time during the stay; need for mechanical ventilation, defined as any documentation of endotracheal intubation during the stay; and length of stay.

Exposure to secondhand smoke was assessed by any documentation of presence or absence of secondhand smoke exposure by any provider. "Any documentation of exposure was considered exposed; documentation of no exposure was considered not exposed," Dr. Wilson said.

She reported findings from 113 children who were included in the final analysis. Of these, 46 (41%) were exposed to secondhand smoke and 67 (59%) were not. The average age of the 113 children was 4 years, and 50% were male. Of the 113 children, 58% were white, 22% were black, 8% were Hispanic, and 3.5% were Asian; race/ethnicity was unknown in the remaining 8.5%. Fewer than half of the children (44%) had public health insurance.

More than three-quarters of the children (78%) had influenza A. In addition, 25% had asthma, 25% had an underlying chronic condition, 14% had documentation of prematurity, 19% required ICU care, and 6% required mechanical ventilation.

None of the potential covariates – including asthma, prematurity, and chronic conditions – were significantly associated with secondhand smoke exposure. However, children exposed to secondhand smoke were significantly more likely to require ICU admission (31% vs. 10% for children with no exposure) and mechanical ventilation (13% vs. 2%, respectively).

The mean length of stay was 2.1 days for children who had no chronic condition or exposure to secondhand smoke, 2.5 days for children who had no chronic condition but had exposure to secondhand smoke, 3.5 days for children who had a chronic condition but no exposure to secondhand smoke, and 11 days for children who had a chronic condition and were exposed to secondhand smoke.

In a logistic regression model controlling for age, gender, race, and type of insurance, exposure to secondhand smoke was significantly associated with ICU admission but chronic conditions were not.

In a logistic regression model limited to exposure to secondhand smoke and chronic conditions, chronic conditions were associated with the need for mechanical ventilation but exposure to secondhand smoke was not.

In a negative binomial regression model using the log-transformed length of stay, controlling for age, gender, race, insurance type, and chronic conditions, exposure to secondhand smoke was associated with an increased length of hospital stay, with an incident rate ratio of 1.9.

Dr. Wilson acknowledged certain limitations of the study, including its single-center design "and the potential for errors in documentation and abstraction," she said. "The exposure measure was reliant on provider documentation ... but provider documentation is more likely to underestimate secondhand smoke exposure in children, so we probably misclassified some children as being non–smoke exposed."

In addition, "there may be other covariates that we were not able to measure because we don’t have documentation in the chart," she said.

Despite such limitations, Dr. Wilson said that the findings support the notion of considering secondhand smoke exposure in risk stratification for children admitted with influenza. "Greater efforts are needed to help parents eliminate their children’s exposure to secondhand smoke," she said. "Parents of children with chronic illness should be aware of the risk of secondhand smoke exposure, and children exposed to secondhand smoke should be a priority group for influenza immunization."

Dr. Wilson disclosed that she is on the speakers bureau for the American Academy of Pediatrics Julius B. Richmond Center of Excellence, with funding from the Flight Attendant Medical Research Institute, National Research Service Award T32, Strong Children’s Research Center Summer Research Program, and the Child Health Corporation of America through a grant to the Pediatric Research in Inpatient Settings Network.

DENVER – Children exposed to secondhand tobacco smoke who are admitted to the hospital for influenza are more likely to require admission to the intensive care unit and have a longer hospital stay than their peers who are not exposed to secondhand smoke.

These effects are even greater for children with chronic illnesses who are exposed to secondhand smoke, Dr. Karen M. Wilson reported at the annual meeting of the Pediatric Academic Societies.

An estimated 18% of children aged 3-11 years are regularly exposed to secondhand tobacco smoke inside the home, said Dr. Wilson, assistant professor of pediatrics at the University of Rochester (N.Y.).

Although secondhand smoke exposure is associated with worse outcomes for children’s illnesses, including respiratory syncytial virus and asthma, "the effect of secondhand smoke exposure on influenza severity in children is unclear," she noted. "More than 40% of preschool children experience influenza at some point. In adults, tobacco smoke increases the risk of influenza infection and the risk of complications."

To determine if children hospitalized with influenza who are exposed to secondhand smoke have more severe illness, Dr. Wilson and her associates conducted a review of 169 medical charts at Golisano Children’s Hospital in Rochester. They generated a list of patients aged 0-15 years with a discharge diagnosis of influenza between 2002 and 2009. The influenza diagnosis was verified by laboratory review.

Measures of severity included intensive care unit admission, defined as admission or transfer to the ICU at any time during the stay; need for mechanical ventilation, defined as any documentation of endotracheal intubation during the stay; and length of stay.

Exposure to secondhand smoke was assessed by any documentation of presence or absence of secondhand smoke exposure by any provider. "Any documentation of exposure was considered exposed; documentation of no exposure was considered not exposed," Dr. Wilson said.

She reported findings from 113 children who were included in the final analysis. Of these, 46 (41%) were exposed to secondhand smoke and 67 (59%) were not. The average age of the 113 children was 4 years, and 50% were male. Of the 113 children, 58% were white, 22% were black, 8% were Hispanic, and 3.5% were Asian; race/ethnicity was unknown in the remaining 8.5%. Fewer than half of the children (44%) had public health insurance.

More than three-quarters of the children (78%) had influenza A. In addition, 25% had asthma, 25% had an underlying chronic condition, 14% had documentation of prematurity, 19% required ICU care, and 6% required mechanical ventilation.

None of the potential covariates – including asthma, prematurity, and chronic conditions – were significantly associated with secondhand smoke exposure. However, children exposed to secondhand smoke were significantly more likely to require ICU admission (31% vs. 10% for children with no exposure) and mechanical ventilation (13% vs. 2%, respectively).

The mean length of stay was 2.1 days for children who had no chronic condition or exposure to secondhand smoke, 2.5 days for children who had no chronic condition but had exposure to secondhand smoke, 3.5 days for children who had a chronic condition but no exposure to secondhand smoke, and 11 days for children who had a chronic condition and were exposed to secondhand smoke.

In a logistic regression model controlling for age, gender, race, and type of insurance, exposure to secondhand smoke was significantly associated with ICU admission but chronic conditions were not.

In a logistic regression model limited to exposure to secondhand smoke and chronic conditions, chronic conditions were associated with the need for mechanical ventilation but exposure to secondhand smoke was not.

In a negative binomial regression model using the log-transformed length of stay, controlling for age, gender, race, insurance type, and chronic conditions, exposure to secondhand smoke was associated with an increased length of hospital stay, with an incident rate ratio of 1.9.

Dr. Wilson acknowledged certain limitations of the study, including its single-center design "and the potential for errors in documentation and abstraction," she said. "The exposure measure was reliant on provider documentation ... but provider documentation is more likely to underestimate secondhand smoke exposure in children, so we probably misclassified some children as being non–smoke exposed."

In addition, "there may be other covariates that we were not able to measure because we don’t have documentation in the chart," she said.

Despite such limitations, Dr. Wilson said that the findings support the notion of considering secondhand smoke exposure in risk stratification for children admitted with influenza. "Greater efforts are needed to help parents eliminate their children’s exposure to secondhand smoke," she said. "Parents of children with chronic illness should be aware of the risk of secondhand smoke exposure, and children exposed to secondhand smoke should be a priority group for influenza immunization."

Dr. Wilson disclosed that she is on the speakers bureau for the American Academy of Pediatrics Julius B. Richmond Center of Excellence, with funding from the Flight Attendant Medical Research Institute, National Research Service Award T32, Strong Children’s Research Center Summer Research Program, and the Child Health Corporation of America through a grant to the Pediatric Research in Inpatient Settings Network.

DENVER – Children exposed to secondhand tobacco smoke who are admitted to the hospital for influenza are more likely to require admission to the intensive care unit and have a longer hospital stay than their peers who are not exposed to secondhand smoke.

These effects are even greater for children with chronic illnesses who are exposed to secondhand smoke, Dr. Karen M. Wilson reported at the annual meeting of the Pediatric Academic Societies.

An estimated 18% of children aged 3-11 years are regularly exposed to secondhand tobacco smoke inside the home, said Dr. Wilson, assistant professor of pediatrics at the University of Rochester (N.Y.).

Although secondhand smoke exposure is associated with worse outcomes for children’s illnesses, including respiratory syncytial virus and asthma, "the effect of secondhand smoke exposure on influenza severity in children is unclear," she noted. "More than 40% of preschool children experience influenza at some point. In adults, tobacco smoke increases the risk of influenza infection and the risk of complications."

To determine if children hospitalized with influenza who are exposed to secondhand smoke have more severe illness, Dr. Wilson and her associates conducted a review of 169 medical charts at Golisano Children’s Hospital in Rochester. They generated a list of patients aged 0-15 years with a discharge diagnosis of influenza between 2002 and 2009. The influenza diagnosis was verified by laboratory review.

Measures of severity included intensive care unit admission, defined as admission or transfer to the ICU at any time during the stay; need for mechanical ventilation, defined as any documentation of endotracheal intubation during the stay; and length of stay.

Exposure to secondhand smoke was assessed by any documentation of presence or absence of secondhand smoke exposure by any provider. "Any documentation of exposure was considered exposed; documentation of no exposure was considered not exposed," Dr. Wilson said.

She reported findings from 113 children who were included in the final analysis. Of these, 46 (41%) were exposed to secondhand smoke and 67 (59%) were not. The average age of the 113 children was 4 years, and 50% were male. Of the 113 children, 58% were white, 22% were black, 8% were Hispanic, and 3.5% were Asian; race/ethnicity was unknown in the remaining 8.5%. Fewer than half of the children (44%) had public health insurance.

More than three-quarters of the children (78%) had influenza A. In addition, 25% had asthma, 25% had an underlying chronic condition, 14% had documentation of prematurity, 19% required ICU care, and 6% required mechanical ventilation.

None of the potential covariates – including asthma, prematurity, and chronic conditions – were significantly associated with secondhand smoke exposure. However, children exposed to secondhand smoke were significantly more likely to require ICU admission (31% vs. 10% for children with no exposure) and mechanical ventilation (13% vs. 2%, respectively).

The mean length of stay was 2.1 days for children who had no chronic condition or exposure to secondhand smoke, 2.5 days for children who had no chronic condition but had exposure to secondhand smoke, 3.5 days for children who had a chronic condition but no exposure to secondhand smoke, and 11 days for children who had a chronic condition and were exposed to secondhand smoke.

In a logistic regression model controlling for age, gender, race, and type of insurance, exposure to secondhand smoke was significantly associated with ICU admission but chronic conditions were not.

In a logistic regression model limited to exposure to secondhand smoke and chronic conditions, chronic conditions were associated with the need for mechanical ventilation but exposure to secondhand smoke was not.

In a negative binomial regression model using the log-transformed length of stay, controlling for age, gender, race, insurance type, and chronic conditions, exposure to secondhand smoke was associated with an increased length of hospital stay, with an incident rate ratio of 1.9.

Dr. Wilson acknowledged certain limitations of the study, including its single-center design "and the potential for errors in documentation and abstraction," she said. "The exposure measure was reliant on provider documentation ... but provider documentation is more likely to underestimate secondhand smoke exposure in children, so we probably misclassified some children as being non–smoke exposed."

In addition, "there may be other covariates that we were not able to measure because we don’t have documentation in the chart," she said.

Despite such limitations, Dr. Wilson said that the findings support the notion of considering secondhand smoke exposure in risk stratification for children admitted with influenza. "Greater efforts are needed to help parents eliminate their children’s exposure to secondhand smoke," she said. "Parents of children with chronic illness should be aware of the risk of secondhand smoke exposure, and children exposed to secondhand smoke should be a priority group for influenza immunization."

Dr. Wilson disclosed that she is on the speakers bureau for the American Academy of Pediatrics Julius B. Richmond Center of Excellence, with funding from the Flight Attendant Medical Research Institute, National Research Service Award T32, Strong Children’s Research Center Summer Research Program, and the Child Health Corporation of America through a grant to the Pediatric Research in Inpatient Settings Network.

DENVER – Children exposed to secondhand tobacco smoke who are admitted to the hospital for influenza are more likely to require admission to the intensive care unit and have a longer hospital stay than their peers who are not exposed to secondhand smoke.

These effects are even greater for children with chronic illnesses who are exposed to secondhand smoke, Dr. Karen M. Wilson reported at the annual meeting of the Pediatric Academic Societies.

An estimated 18% of children aged 3-11 years are regularly exposed to secondhand tobacco smoke inside the home, said Dr. Wilson, assistant professor of pediatrics at the University of Rochester (N.Y.).

Although secondhand smoke exposure is associated with worse outcomes for children’s illnesses, including respiratory syncytial virus and asthma, "the effect of secondhand smoke exposure on influenza severity in children is unclear," she noted. "More than 40% of preschool children experience influenza at some point. In adults, tobacco smoke increases the risk of influenza infection and the risk of complications."

To determine if children hospitalized with influenza who are exposed to secondhand smoke have more severe illness, Dr. Wilson and her associates conducted a review of 169 medical charts at Golisano Children’s Hospital in Rochester. They generated a list of patients aged 0-15 years with a discharge diagnosis of influenza between 2002 and 2009. The influenza diagnosis was verified by laboratory review.

Measures of severity included intensive care unit admission, defined as admission or transfer to the ICU at any time during the stay; need for mechanical ventilation, defined as any documentation of endotracheal intubation during the stay; and length of stay.

Exposure to secondhand smoke was assessed by any documentation of presence or absence of secondhand smoke exposure by any provider. "Any documentation of exposure was considered exposed; documentation of no exposure was considered not exposed," Dr. Wilson said.

She reported findings from 113 children who were included in the final analysis. Of these, 46 (41%) were exposed to secondhand smoke and 67 (59%) were not. The average age of the 113 children was 4 years, and 50% were male. Of the 113 children, 58% were white, 22% were black, 8% were Hispanic, and 3.5% were Asian; race/ethnicity was unknown in the remaining 8.5%. Fewer than half of the children (44%) had public health insurance.

More than three-quarters of the children (78%) had influenza A. In addition, 25% had asthma, 25% had an underlying chronic condition, 14% had documentation of prematurity, 19% required ICU care, and 6% required mechanical ventilation.

None of the potential covariates – including asthma, prematurity, and chronic conditions – were significantly associated with secondhand smoke exposure. However, children exposed to secondhand smoke were significantly more likely to require ICU admission (31% vs. 10% for children with no exposure) and mechanical ventilation (13% vs. 2%, respectively).

The mean length of stay was 2.1 days for children who had no chronic condition or exposure to secondhand smoke, 2.5 days for children who had no chronic condition but had exposure to secondhand smoke, 3.5 days for children who had a chronic condition but no exposure to secondhand smoke, and 11 days for children who had a chronic condition and were exposed to secondhand smoke.

In a logistic regression model controlling for age, gender, race, and type of insurance, exposure to secondhand smoke was significantly associated with ICU admission but chronic conditions were not.

In a logistic regression model limited to exposure to secondhand smoke and chronic conditions, chronic conditions were associated with the need for mechanical ventilation but exposure to secondhand smoke was not.

In a negative binomial regression model using the log-transformed length of stay, controlling for age, gender, race, insurance type, and chronic conditions, exposure to secondhand smoke was associated with an increased length of hospital stay, with an incident rate ratio of 1.9.

Dr. Wilson acknowledged certain limitations of the study, including its single-center design "and the potential for errors in documentation and abstraction," she said. "The exposure measure was reliant on provider documentation ... but provider documentation is more likely to underestimate secondhand smoke exposure in children, so we probably misclassified some children as being non–smoke exposed."

In addition, "there may be other covariates that we were not able to measure because we don’t have documentation in the chart," she said.

Despite such limitations, Dr. Wilson said that the findings support the notion of considering secondhand smoke exposure in risk stratification for children admitted with influenza. "Greater efforts are needed to help parents eliminate their children’s exposure to secondhand smoke," she said. "Parents of children with chronic illness should be aware of the risk of secondhand smoke exposure, and children exposed to secondhand smoke should be a priority group for influenza immunization."

Dr. Wilson disclosed that she is on the speakers bureau for the American Academy of Pediatrics Julius B. Richmond Center of Excellence, with funding from the Flight Attendant Medical Research Institute, National Research Service Award T32, Strong Children’s Research Center Summer Research Program, and the Child Health Corporation of America through a grant to the Pediatric Research in Inpatient Settings Network.

DENVER – Children exposed to secondhand tobacco smoke who are admitted to the hospital for influenza are more likely to require admission to the intensive care unit and have a longer hospital stay than their peers who are not exposed to secondhand smoke.

These effects are even greater for children with chronic illnesses who are exposed to secondhand smoke, Dr. Karen M. Wilson reported at the annual meeting of the Pediatric Academic Societies.

An estimated 18% of children aged 3-11 years are regularly exposed to secondhand tobacco smoke inside the home, said Dr. Wilson, assistant professor of pediatrics at the University of Rochester (N.Y.).

Although secondhand smoke exposure is associated with worse outcomes for children’s illnesses, including respiratory syncytial virus and asthma, "the effect of secondhand smoke exposure on influenza severity in children is unclear," she noted. "More than 40% of preschool children experience influenza at some point. In adults, tobacco smoke increases the risk of influenza infection and the risk of complications."

To determine if children hospitalized with influenza who are exposed to secondhand smoke have more severe illness, Dr. Wilson and her associates conducted a review of 169 medical charts at Golisano Children’s Hospital in Rochester. They generated a list of patients aged 0-15 years with a discharge diagnosis of influenza between 2002 and 2009. The influenza diagnosis was verified by laboratory review.

Measures of severity included intensive care unit admission, defined as admission or transfer to the ICU at any time during the stay; need for mechanical ventilation, defined as any documentation of endotracheal intubation during the stay; and length of stay.

Exposure to secondhand smoke was assessed by any documentation of presence or absence of secondhand smoke exposure by any provider. "Any documentation of exposure was considered exposed; documentation of no exposure was considered not exposed," Dr. Wilson said.

She reported findings from 113 children who were included in the final analysis. Of these, 46 (41%) were exposed to secondhand smoke and 67 (59%) were not. The average age of the 113 children was 4 years, and 50% were male. Of the 113 children, 58% were white, 22% were black, 8% were Hispanic, and 3.5% were Asian; race/ethnicity was unknown in the remaining 8.5%. Fewer than half of the children (44%) had public health insurance.

More than three-quarters of the children (78%) had influenza A. In addition, 25% had asthma, 25% had an underlying chronic condition, 14% had documentation of prematurity, 19% required ICU care, and 6% required mechanical ventilation.

None of the potential covariates – including asthma, prematurity, and chronic conditions – were significantly associated with secondhand smoke exposure. However, children exposed to secondhand smoke were significantly more likely to require ICU admission (31% vs. 10% for children with no exposure) and mechanical ventilation (13% vs. 2%, respectively).

The mean length of stay was 2.1 days for children who had no chronic condition or exposure to secondhand smoke, 2.5 days for children who had no chronic condition but had exposure to secondhand smoke, 3.5 days for children who had a chronic condition but no exposure to secondhand smoke, and 11 days for children who had a chronic condition and were exposed to secondhand smoke.

In a logistic regression model controlling for age, gender, race, and type of insurance, exposure to secondhand smoke was significantly associated with ICU admission but chronic conditions were not.

In a logistic regression model limited to exposure to secondhand smoke and chronic conditions, chronic conditions were associated with the need for mechanical ventilation but exposure to secondhand smoke was not.

In a negative binomial regression model using the log-transformed length of stay, controlling for age, gender, race, insurance type, and chronic conditions, exposure to secondhand smoke was associated with an increased length of hospital stay, with an incident rate ratio of 1.9.

Dr. Wilson acknowledged certain limitations of the study, including its single-center design "and the potential for errors in documentation and abstraction," she said. "The exposure measure was reliant on provider documentation ... but provider documentation is more likely to underestimate secondhand smoke exposure in children, so we probably misclassified some children as being non–smoke exposed."

In addition, "there may be other covariates that we were not able to measure because we don’t have documentation in the chart," she said.

Despite such limitations, Dr. Wilson said that the findings support the notion of considering secondhand smoke exposure in risk stratification for children admitted with influenza. "Greater efforts are needed to help parents eliminate their children’s exposure to secondhand smoke," she said. "Parents of children with chronic illness should be aware of the risk of secondhand smoke exposure, and children exposed to secondhand smoke should be a priority group for influenza immunization."

Dr. Wilson disclosed that she is on the speakers bureau for the American Academy of Pediatrics Julius B. Richmond Center of Excellence, with funding from the Flight Attendant Medical Research Institute, National Research Service Award T32, Strong Children’s Research Center Summer Research Program, and the Child Health Corporation of America through a grant to the Pediatric Research in Inpatient Settings Network.

DENVER – There’s a new reason to keep children away from secondhand smoke: It raises systolic blood pressure in boys, a University of Wisconsin, Madison, study suggests.

However, the mean increase was minimal – just 1.6 mm Hg – when researchers compared boys exposed to secondhand smoke with those who were not. "For an individual child, that’s not necessarily something you would worry about" in the short term, lead investigator and environmental health research fellow Jill Baumgartner, Ph.D., said the annual meeting of the Pediatric Academic Societies.

© pmphoto/istock.com

Still, elevated blood pressure in childhood can lead to adult hypertension and, "We found a similar [blood pressure] effect for children exposed to really low levels as for children exposed to higher levels, [reinforcing] the notion that there really is no acceptable exposure level for secondhand smoke," she said.

The study by Dr. Baumgartner and her colleagues is the first to demonstrate a link between secondhand smoke and blood pressure changes in children. Secondhand smoke already is known to decrease lung growth, increase the risk for sudden infant death, and cause respiratory problems in children, among other factors.

Conversely, however, Dr. Baumgartner and her colleagues also discovered that girls exposed to secondhand smoke had slightly lower systolic blood pressure than did other girls, a mean of 1.8 mm Hg.

"I think there could be something going on there, but we are not sure what it is," she said. "It’s actually supported in the academic literature" that smoking raises blood pressure in males but can have the opposite effect in females.

She hesitated to call female gender a protective factor, because the drop in blood pressure could signal some other deleterious effect of smoke exposure.

In their cross-sectional retrospective analysis, the researchers mined National Health and Nutrition Examination Survey data from 1999-2006, identifying 6,421 children aged 8-17, 52% girls, 34% white, 27% Mexican American, and about 32% exposed to secondhand smoke.

They defined exposure as having at least one smoker in the house and by serum cotinine levels of 0.01-14 ng/mL. Children with levels above 14 ng/mL were excluded because that level of the nicotine metabolite indicates that they themselves smoke. Having a smoker in the house strongly correlated with cotinine levels.

Through matching and statistical adjustments, the researchers controlled for a range of confounding variables, including age, sex, body mass index, physical activity, survey year, health insurance, household income, and potassium, caffeine, and sodium intake.

There was no dose-response relationship between cotinine levels and blood pressure. Elevations were similar in boys and drops similar in girls across cotinine levels. In exposed boys, increases in systolic blood pressure ranged from 1-1.9 mm Hg. In exposed girls, drops ranged from 1.5-2.6 mmHg. Results were statistically significant.

"If you looked at higher doses, you might see a dose response, but in this range of exposure, because it’s so low" it wasn’t apparent, Dr. Baumgartner said.

The next step is a longitudinal study to see whether blood pressure changes vary with variations in secondhand smoke exposure. "We are also trying to better understand the biologic drivers of tobacco smoke and blood pressure in kids," she said.

In the meantime, "If you are physician and have a parent coming in saying ‘I am reducing the amount I’m smoking,’ we are showing that’s not quite enough. [They] need to stop smoking, because even at really low levels, exposure is having an effect on kids and their blood pressure," she said.

Dr. Baumgartner said she has no disclosures. The study was funded by an Academic Pediatric Association Young Investigators Grant.

DENVER – There’s a new reason to keep children away from secondhand smoke: It raises systolic blood pressure in boys, a University of Wisconsin, Madison, study suggests.

However, the mean increase was minimal – just 1.6 mm Hg – when researchers compared boys exposed to secondhand smoke with those who were not. "For an individual child, that’s not necessarily something you would worry about" in the short term, lead investigator and environmental health research fellow Jill Baumgartner, Ph.D., said the annual meeting of the Pediatric Academic Societies.

© pmphoto/istock.com

Still, elevated blood pressure in childhood can lead to adult hypertension and, "We found a similar [blood pressure] effect for children exposed to really low levels as for children exposed to higher levels, [reinforcing] the notion that there really is no acceptable exposure level for secondhand smoke," she said.

The study by Dr. Baumgartner and her colleagues is the first to demonstrate a link between secondhand smoke and blood pressure changes in children. Secondhand smoke already is known to decrease lung growth, increase the risk for sudden infant death, and cause respiratory problems in children, among other factors.

Conversely, however, Dr. Baumgartner and her colleagues also discovered that girls exposed to secondhand smoke had slightly lower systolic blood pressure than did other girls, a mean of 1.8 mm Hg.

"I think there could be something going on there, but we are not sure what it is," she said. "It’s actually supported in the academic literature" that smoking raises blood pressure in males but can have the opposite effect in females.

She hesitated to call female gender a protective factor, because the drop in blood pressure could signal some other deleterious effect of smoke exposure.

In their cross-sectional retrospective analysis, the researchers mined National Health and Nutrition Examination Survey data from 1999-2006, identifying 6,421 children aged 8-17, 52% girls, 34% white, 27% Mexican American, and about 32% exposed to secondhand smoke.

They defined exposure as having at least one smoker in the house and by serum cotinine levels of 0.01-14 ng/mL. Children with levels above 14 ng/mL were excluded because that level of the nicotine metabolite indicates that they themselves smoke. Having a smoker in the house strongly correlated with cotinine levels.

Through matching and statistical adjustments, the researchers controlled for a range of confounding variables, including age, sex, body mass index, physical activity, survey year, health insurance, household income, and potassium, caffeine, and sodium intake.

There was no dose-response relationship between cotinine levels and blood pressure. Elevations were similar in boys and drops similar in girls across cotinine levels. In exposed boys, increases in systolic blood pressure ranged from 1-1.9 mm Hg. In exposed girls, drops ranged from 1.5-2.6 mmHg. Results were statistically significant.

"If you looked at higher doses, you might see a dose response, but in this range of exposure, because it’s so low" it wasn’t apparent, Dr. Baumgartner said.

The next step is a longitudinal study to see whether blood pressure changes vary with variations in secondhand smoke exposure. "We are also trying to better understand the biologic drivers of tobacco smoke and blood pressure in kids," she said.

In the meantime, "If you are physician and have a parent coming in saying ‘I am reducing the amount I’m smoking,’ we are showing that’s not quite enough. [They] need to stop smoking, because even at really low levels, exposure is having an effect on kids and their blood pressure," she said.

Dr. Baumgartner said she has no disclosures. The study was funded by an Academic Pediatric Association Young Investigators Grant.

DENVER – There’s a new reason to keep children away from secondhand smoke: It raises systolic blood pressure in boys, a University of Wisconsin, Madison, study suggests.

However, the mean increase was minimal – just 1.6 mm Hg – when researchers compared boys exposed to secondhand smoke with those who were not. "For an individual child, that’s not necessarily something you would worry about" in the short term, lead investigator and environmental health research fellow Jill Baumgartner, Ph.D., said the annual meeting of the Pediatric Academic Societies.

© pmphoto/istock.com

Still, elevated blood pressure in childhood can lead to adult hypertension and, "We found a similar [blood pressure] effect for children exposed to really low levels as for children exposed to higher levels, [reinforcing] the notion that there really is no acceptable exposure level for secondhand smoke," she said.

The study by Dr. Baumgartner and her colleagues is the first to demonstrate a link between secondhand smoke and blood pressure changes in children. Secondhand smoke already is known to decrease lung growth, increase the risk for sudden infant death, and cause respiratory problems in children, among other factors.

Conversely, however, Dr. Baumgartner and her colleagues also discovered that girls exposed to secondhand smoke had slightly lower systolic blood pressure than did other girls, a mean of 1.8 mm Hg.

"I think there could be something going on there, but we are not sure what it is," she said. "It’s actually supported in the academic literature" that smoking raises blood pressure in males but can have the opposite effect in females.

She hesitated to call female gender a protective factor, because the drop in blood pressure could signal some other deleterious effect of smoke exposure.

In their cross-sectional retrospective analysis, the researchers mined National Health and Nutrition Examination Survey data from 1999-2006, identifying 6,421 children aged 8-17, 52% girls, 34% white, 27% Mexican American, and about 32% exposed to secondhand smoke.

They defined exposure as having at least one smoker in the house and by serum cotinine levels of 0.01-14 ng/mL. Children with levels above 14 ng/mL were excluded because that level of the nicotine metabolite indicates that they themselves smoke. Having a smoker in the house strongly correlated with cotinine levels.

Through matching and statistical adjustments, the researchers controlled for a range of confounding variables, including age, sex, body mass index, physical activity, survey year, health insurance, household income, and potassium, caffeine, and sodium intake.

There was no dose-response relationship between cotinine levels and blood pressure. Elevations were similar in boys and drops similar in girls across cotinine levels. In exposed boys, increases in systolic blood pressure ranged from 1-1.9 mm Hg. In exposed girls, drops ranged from 1.5-2.6 mmHg. Results were statistically significant.

"If you looked at higher doses, you might see a dose response, but in this range of exposure, because it’s so low" it wasn’t apparent, Dr. Baumgartner said.

The next step is a longitudinal study to see whether blood pressure changes vary with variations in secondhand smoke exposure. "We are also trying to better understand the biologic drivers of tobacco smoke and blood pressure in kids," she said.

In the meantime, "If you are physician and have a parent coming in saying ‘I am reducing the amount I’m smoking,’ we are showing that’s not quite enough. [They] need to stop smoking, because even at really low levels, exposure is having an effect on kids and their blood pressure," she said.

Dr. Baumgartner said she has no disclosures. The study was funded by an Academic Pediatric Association Young Investigators Grant.