Day care attendance, recurrent respiratory tract infections and asthma

Objective Our objective was to use a causal model for childhood asthma to d etermine whether the effect of day care attendance on asthma was mediated b y recurrent respiratory tract infections. Design A cross-sectional survey among 1447 children aged 6-16 years in Oslo . Their parents completed written questionnaires. A recursive legit model w as used to estimate direct effects in terms of adjusted odds ratios (aOR). Results Year of birth, number of siblings and length of maternal education were significantly associated with day care attendance. Attendance at day c are increased the risk of early infections, aOR = 1.8 (1.3-2.5), and infect ions were associated with asthma, aOR = 4.9 (3.4-7.3). The crude associatio n between day care and asthma was cOR = 1.5 (1.0-2.2), whereas the estimate d direct effect was small and nonsignificant, aOR = 1.2 (0.8-1.9). The resu lts may be influenced by overreporting of infections among parents of child ren with asthma. Conclusions Our results suggest that children who attend day care have an i ncreased risk of asthma with early infections as a mediator of risk.