The effect of educational level on the incidence of asthma and respiratory symptoms

Few studies have examined the impact of socioeconomic status on the incidence of asthma and respiratory symptoms. Between 1985 and 1996/97, we conducted an 11-years community cohort study with 2819 subjects, aged 15–70 years at baseline, in Western Norway. We examined the cumulative incidence of asthma and respiratory symptoms by educational level (primary, secondary, and university), as well as estimating the odds ratios (ORs) of educational level on the incidences, after adjustment for sex, age, hay fever, smoking habits, pack years, and occupational exposure. For all respiratory symptoms, the incidences decreased with increasing educational level. The cumulative incidence of asthma was 5.3%, 4.1%, and 1.8%, respectively, for those with a primary educational level, secondary educational level, and university level. Subjects with a primary educational level had adjusted ORs (95% CI) from 1.4 (0.9, 2.3) for the incidence of chronic cough to 2.5 (1.6, 4.0) for the incidence of dyspnea grade 2, compared to those with a university level education. The adjusted OR (95% CI) for the incidence of asthma was 2.1 (1.01, 4.4) in subjects with a primary educational level, and 2.0 (1.04, 3.6) in subjects with a secondary educational level, compared to subjects with a university educational level. In conclusion, subjects with a lower educational level had a higher risk of developing asthma and respiratory symptoms, after adjustment for sex, age, hay fever, smoking, and occupational exposure.