Persisting disparities in hepatitis B diagnoses, associated risk factors, and time to diagnosis among migrants compared with Danish-born populations: a matched cohort study.

Hepatitis B virus (HBV) remains a major public health concern globally despite the availability of an effective vaccine. In Europe, HBV risk is particularly high among those originating from areas with high prevalence rates. We investigated diagnosis rates and risk factors for HBV infections among migrants compared to Danish-born populations. Our matched cohort study included migrants matched 1:6 with Danish-born individuals over a 23-year period. We calculated HBV diagnosis rates per 10 000 person-years. A multivariate quasi-Poisson regression analysis was done across the entire cohort, to compare adjusted incidence rate ratios (aIRRs) between the Danish-born and migrant cohorts. A further multivariate analysis was done in the migrant cohort only, to examine factors associated with diagnosis. Time to diagnosis was also compared within the migrant cohort. 179 110 migrants and 1 049 345 Danish-born individuals were included in the study cohort, among whom there were 1362 HBV diagnoses (migrants: 1118; Danish-born: 244). Migrants had a higher HBV diagnosis rate compared to Danish-born (aIRR 30.6; 95% CI: 26.7-35.2). A higher rate of substance use disorders, hepatitis C, and HIV co-infection were observed among Danish-born cases. Within the migrant cohort, hepatitis C diagnosis, region of origin (Southeast Asia and Pacific, African region), and migrant status were associated with HBV diagnosis and the average time from arrival to diagnosis was 5.4 years. Migrants are at increased risk for HBV and may experience diagnostic delays, particularly those who fall outside of routine screening processes for pregnant women and on-arrival health assessments. At-risk migrant groups should be engaged early in culturally competent screening programs to increase health equity and meet WHO 2030 HBV elimination goals.