Patterns of environmental tobacco smoke exposure and their association with asthma in adolescence

Introduction: Environmental tobacco smoke (ETS) is a modifiable exposure associated with asthma in children. The role of the timing of ETS exposure and longitudinal patterns of exposure on prevalence of asthma in adolescence is unclear. This study uses three methods to determine timing of ETS exposure and lifetime exposure patterns from repeated measures and their association with asthma at age 14. Methods: We used data from the population-based Dutch PIAMA birth cohort study. ETS exposure was assessed via parental questionnaires completed annually from birth to age 8, and at ages 11-12 and 14. Exposure was determined in 3 ways: a) time windows i.e. prenatal, infancy, preschool, primary school and secondary school; b) total cumulative exposure of the study period using sum scores; c) longitudinal pattern of exposure using latent class growth modeling (LCGM). Logistic regression was used to determine association between these estimates of exposures and asthma at age 14, adjusted for parental education, par...