Severe and differential underestimation of self-reported smoking prevalence in Chinese adolescents.

BACKGROUND Evaluating the progress of tobacco control across the world heavily relies on smoking prevalence estimates. Those estimates are often based on surveys of self-reported cigarette smoking status. The accuracy varies among populations with different social and cultural backgrounds. PURPOSE The objective of this study was to estimate the prevalence of smoking and assess the accuracy of self-report smoking status in Chinese adolescents. METHOD This population-based cross-sectional survey included 10,934 adolescents aged 12 to 18 years from 17 schools in Shanghai, China. Data on adolescents' smoking status were collected from adolescents' self-reporting and from parents' questionnaires, separately. Based on the data of two sources, the total number of smokers among the study participants was estimated using a capture-recapture method. RESULTS Among 5,452 girls and 5,482 boys, the prevalence estimates of self-reported smoking were 13.6% (748) and 5.2% (284) for boys and girls, respectively. Parents only identified smaller proportions of smoking adolescents: 2.9% (160) boys and 0.6% (30) girls. Using the capture-recapture method, we estimated the prevalence of smoking as 18.3% (95% CI 16.4, 20.3) for boys and 14.2% (95% CI 7.6, 20.8) for girls. CONCLUSION Reliance on self-reporting to identify smokers among Chinese adolescents significantly underestimates the number of smokers, particularly among Chinese girls. Self-reported smokers only represent less than half of actual smokers in girls. Our findings are important for monitoring smoking trends and evaluating tobacco control interventions among Chinese adolescents.