Enhancing population-wide administrative data to better understand mortality risk in underserved groups

SSM Popul Health. 2026 May 14;34:101933. doi: 10.1016/j.ssmph.2026.101933. eCollection 2026 Jun.

ABSTRACT

BACKGROUND: Underserved groups (USGs) face significant health inequalities, but studying these populations is often limited by small sample sizes and low participation in voluntary studies. Population-wide Census data provides an important opportunity to address some of these challenges. This study examined mortality outcomes among multiple USGs in Northern Ireland using Census-linked mortality data.

METHODS: We conducted a population-wide cohort study using the Northern Ireland Mortality Study 2021, linking Census data to death records for all individuals aged ≥16 years (n = 1,463,459) from 21 March 2021 to 31 December 2023. USGs included ethnic minorities, migrants, those with limited English, LGB+ (lesbian, gay, bisexual, and other sexual minorities) individuals, religious minorities, and Irish Travellers. Outcomes included all-cause mortality, avoidable mortality, and deaths of despair (comprising suicide, alcohol-related deaths, and drug-related deaths), with suicide also examined as a separate outcome. Cox proportional hazards models were used to estimate associations with sequential adjustment for sociodemographic and health-related factors.

RESULTS: Of 1,463,459 cohort members, 414,540 (28.3%) belonged to at least one USG. During follow-up, 36,525 (2.5%) individuals died. In unadjusted models, ethnic minorities, migrants, those with limited English, and religious minorities had lower all-cause mortality risk, whilst LGB + individuals had elevated risk (HR 1.24, 95% CI 1.20-1.29). After full adjustment, estimates remained below 1.00 for all groups except LGB + individuals. For LGB + individuals, all-cause mortality was attenuated towards the null, but deaths of despair remained elevated (HR 1.21, 95% CI 1.02-1.43).

CONCLUSIONS: Most USGs had lower mortality risks than their reference populations. However, LGB + individuals had elevated risk of deaths of despair. These findings demonstrate the value of population-wide data for understanding heterogeneity in mortality across USGs.

PMID:42199987 | PMC:PMC13199807 | DOI:10.1016/j.ssmph.2026.101933