Relation of occupational exposure to respiratory symptoms and asthma in a general population sample: Self-reported versus interview-based exposure data

The objective of this study was to examine how the consistency of self-repo rted exposure to dust or gas, asbestos, and quartz varied between subjects with and those without respiratory symptoms and asthma in a Norwegian commu nity sample (n=714) in 1987-1988. Exposure characterization obtained in a s tructured work history interview was used as the "gold standard" The author s also wanted to assess how the exposure-disease relation differed when the exposure was based on self-reported versus interview-obtained data. The pr evalence of self-reported exposure to dust or gas, asbestos, and quartz was 28%, 5%, and 4%, respectively. The sensitivity of the self-reported exposu re data varied from 21% to 64% and was higher in those with than in those w ithout the respiratory disorders. The specificity varied from 78% to 100% a nd was lower in those with than in those without the respiratory disorders. The sex-, age-, and smoking-adjusted odds ratios of the respiratory disord ers in those with exposure to dust or gas and to asbestos were only slightl y reduced when misclassification was taken into account. The corresponding numbers for exposure to quartz were halved and lost their statistical signi ficance when the misclassification was allowed for. In this general populat ion sample, the self-reported occupational, airborne exposure data were dif ferentially misclassified by disease status.