The present study investigated the relationship between socioeconomic status, using measures of occupational class and education level, and the prevalence and incidence of asthma (with and without atopy) and chronic bronchitis using data from the European Community Respiratory Health Survey (ECRHS). Asthma and chronic bronchitis were studied prospectively within the ECRHS (n = 9,023). Incidence analyses comprised subjects with no history of asthma or bronchitis at baseline. Asthma symptoms were also assessed as a continuous score. Bronchitis risk was associated with low educational level (prevalence odds ratio (POR) 1.9; 95% confidence interval (CI) 1.4-2.8) and occupational class (1.8; 1.2-2.7). Incident bronchitis also increased with low educational level (risk ratio (RR) 2.8; 95%CI 1.5-5.4). Prevalent and incident asthma with no atopy were associated with low educational level. Subjects in the low occupational class (incident risk ratio (IRR) 1.4; 95%CI 1.2-1.7) and education group (IRR 1.3; 95% CI 1.1-1.6) had higher mean asthma scores than those in higher socioeconomic groups. Lower educational level was associated with increased risk of prevalent and incident chronic bronchitis and asthma with no atopy. Lower socioeconomic groups tended to have a higher prevalence and incidence of asthma, particularly higher mean asthma scores. Adjustment for variables associated with asthma and bronchitis explained little of the observed health differences by socioeconomic status.
