Sociodemographic characteristics of women with endometriosis: A Danish register-based case-control study

OBJECTIVE: To describe sociodemographic characteristics of women with hospital diagnosed endometriosis in Denmark and compare them with women without endometriosis. STUDY DESIGN: Case-control study using Danish national registers. Cases were identified as women aged 14-84 years receiving a first-time hospital-based diagnosis of endometriosis in 1991-2021 (n = 37.709). Each case was matched based on date of diagnosis and birth year to five controls without endometriosis (n = 188.545). Information on diagnosis of endometriosis and sociodemographic factors was obtained from Danish registers. Descriptive statistics and unadjusted and adjusted conditional logistic regression analyses were used to investigate the association between a diagnosis of endometriosis and sociodemographic factors. RESULTS: For family-based socioeconomic status, women in all groups other than the employed category (both higher and lower socioeconomic status) had lower odds of receiving a diagnosis (ORs ranging from 0.78 to 0.91). Women with primary education, master or equivalent, and PhD had lower odds of a diagnosis (ORs 0.79-0.93) compared to upper secondary education. Compared to couples, singles and "other" had slightly lower odds of a diagnosis (ORs 0.91-0.94). Women of Danish origin and immigrants had similar odds of a diagnosis whereas descendants had lower odds (0.85 (95% CI: 0.76-0.95)) when compared to the two other groups. CONCLUSION: Sociodemographic factors were found to be associated with receiving a hospital diagnosis of endometriosis. However, only smaller differences and a mixed pattern were found.