All-cause and cause-specific mortality differences between migrant workers and local workers: a population-based cohort study in Denmark

Migrants are prone to poor working conditions in high-risk industries, yet little is known about their mortality risk compared to local-born workers. This study compares all-cause and cause-specific mortality between foreign-born and local-born workers, and identifies at-risk foreign-born workers. A nationwide register-based cohort study was performed using data on migrant workers obtaining residence permits in Denmark during 2015-22. Comparison group comprised Danish-born workers matched by age and sex. Survival analysis using extended Cox model was used to estimate all-cause and cause-specific mortality. Subgroup analysis was conducted by region of birth, economic sector, and occupation. Male migrant workers from Central Europe, Eastern Europe, and Central Asia had higher risk of all-cause mortality than Danish-born workers (HR = 1.30 [95% CI: 1.09-1.54]), attributed to accident deaths (HR = 1.64 [1.06-2.53]), whereas migrants from other regions had lower risk. Migrant workers from these regions were more likely to work in high-risk economic sectors and occupations, such as agriculture and construction. When stratified by economic sector and by occupation, among the elementary occupations, migrant workers from these regions still had a higher risk of all-cause mortality (HR = 1.70 [1.10-2.64]) and accident mortality (HR = 1.51 [1.22-1.85]) than Danish-born workers. Migrant workers from Central Europe, Eastern Europe, and Central Asia are more likely to die from accidents than Danish-born workers. This increased risk was partially explained by their higher representation in at-risk sectors and occupations. There is a need to better understand the structural determinants of health faced by these migrants, particularly in elementary occupations, to prevent avoidable deaths.