Children with asthma who are exposed to secondhand smoke (SHS) are at greater risk of being hospitalized because of asthma exacerbation, according to a systematic review by Zhen Wang, Ph.D., and associates.

The review identified 25 relevant studies, which found that asthmatic children exposed to SHS were nearly twice as likely to be hospitalized because of their asthma as were children who were not exposed, with an odds ratio of 1.85. The OR for visits to the emergency department or urgent care was also significantly higher in children exposed to SHS at 1.66.

Pulmonary function in children with asthma exposed to SHS was worse than in nonexposed children. The OR for wheeze symptoms was 1.32, and the forced expiratory volume in 1 second/forced vital capacity ratio was much lower, with an OR of –3.34.

“Assessment of SHS (subjective and objective measurements) should be an integral part of asthma care in children. This will help address and eliminate modifiable risk factors and improve the overall health of children with asthma,” the investigators concluded.

Find the study in Annals of Allergy, Asthma, and Immunology ( doi: 10.1016/j.anai.2015.08.005 ).