Educational level and occupation as risk factors for inflammatory bowel diseases: A nationwide study based on hospitalizations in Sweden

Background: The aim of this study was to investigate possible associations between educational level, occupation, and hospitalization for inflammatory bowel disease. Methods: A nationwide database was constructed by linking the Swedish Census to the Hospital Discharge Register in order to obtain data on all first hospitalizations for Crohn's disease (CD) and ulcerative colitis (UC) in Sweden during the study period (1970-2004). Standardized incidence ratios (SIRs) and 95% confidence intervals (CIs) were calculated by educational level and occupation for men and women ≥30 years. Three cohorts were defined based on occupational titles recorded in the Swedish census data in 1970 and 1980. Results: Significantly decreased SIRs for CD were observed for both men and women who had an educational level of >12 years. Among men, significantly increased SIRs for CD were present in all 3 cohorts among "drivers." Male "religious, juridical, and other social-science-related workers," "textile workers," and "glass, ceramic, and tile workers," and female "clerical workers," "mechanics and iron and metalware workers," and "printers and related workers" had a significantly increased SIR for CD that was present in 1 of the 3 cohorts. For UC, male "postal and communication workers," "smelters and metal foundry workers," and "chemical process workers," and female "wood workers" had a significantly increased SIR for UC that was present in at least 1 of the 3 cohorts. Conclusions: Educational level and occupation seem to have a minor effect on the population's likelihood of hospitalization for CD and UC.