Prevalence of bronchial asthma and association with environmental tobacco smoke exposure in adolescent school children in Chandigarh, north India.

Prevalence of asthma and its association with environmental tobacco smoke (ETS) exposure were examined among adolescent schoolchildren in Chandigarh, India. Using a previously standardized questionnaire, data from 9090 students in the 9- to 20-year age range were analyzed. There were 4367 (48%) boys, in whom the observed prevalence of asthma was 2.6%. Among 4723 (52%) girls, asthma was present in 90 (1.9%) students. Presence of one or more respiratory symptoms was reported by 31% students. More students with asthma had either parents or other family members smoking at home as compared to nonasthmatics (41% vs. 28%, p<0.0001). The odds ratio for being asthmatic for patients exposed to ETS compared to those not exposed to ETS was 1.78 (95% confidence interval 1.33-2.31). ETS was also positively associated with prevalence of all the respiratory symptoms, with odds ratios varying between 1.6 and 2.25.