Secondhand smoke exposure can greatly increase a child's chance of being readmitted to the hospital within a year of being admitted for asthma, a new study in the journal Pediatrics found.

According to the researchers from Cincinnati Children's Hospital Medical Center and Penn State Milton S. Hershey Children's Hospital, the finding supports the idea that measurements of tobacco exposure could be used to target efforts focused on smoking reduction and, ultimately, limit the number future hospitalizations.

In order to measure tobacco exposure, the researchers looked at cotinine - produced when the body breaks nicotine down - levels in the blood and saliva of more than 600 children between the ages of 1-16. All were admitted to Cincinnati Children's between August 2010 and October 2011 and were followed for at least 12 months after.

While there was no correlation between caregiver report of tobacco exposure and readmission, cotinine measurements showed that children exposed to secondhand smoke were more than twice as likely to be readmitted than those who were not exposed.

"The ability to measure serum and salivary cotinine levels presents the possibility of an objective measure that can be obtained when a child is seen in the emergency department or in the hospital and may be used to predict future hospitalizations," said Dr. Robert Kahn, associate director of general and community pediatrics at Cincinnati Children's and senior author of the study.

"Such a measure for exposure to tobacco smoke could be used to target specific interventions at caregivers of those children before discharge from the hospital. Several interventions, including parental counseling and contact with the primary care physician, could be adopted in clinical practice."

Beyond the physical burden placed on the children, the researchers noted the financial one for insurance companies.

"Of the 619 children in the study, 76 percent were covered by Medicaid," said Dr. Judie Howrylak, a physician at Hershey Children's and lead author of the study. "Certainly there could be a financial incentive for insurance companies to help caregivers quit smoking, rather than pay the downstream costs of a future asthma readmission."