The association of sex and socioeconomic status with multimorbidity: results from the UK Biobank

INTRODUCTION: Multimorbidity, defined as the coexistence of two or more chronic diseases, is common. It is not well-understood how multimorbidity differs by sex and socioeconomic status.

METHODS: Cross-sectional data from the UK Biobank in 2006-10 were used. Socioeconomic status was determined from area-based deprivation and individual education level. Multimorbidity was defined as having two or more chronic diseases, identified through linked hospital-admission data between 1995 and 2022. Modified Poisson regression was used to estimate age-adjusted prevalence relative risks (RRs) and women-to-men ratio of RRs with 95 % confidence intervals (CIs) for association of socioeconomic status with multimorbidity.

RESULTS: A total of 502,364 individuals (54 % women) were included. Forty two percent of women and 48 % of men had multimorbidity, with the most common disease combination being cancer and hypertension, and hypertension being the most common single condition in both sexes (68 % of men and 58 % of women). The age-adjusted risk of multimorbidity was higher in men than in women (RR, 1.12, 95 % CI, 1.11-1.13). Compared to those in the least deprived areas, the age-adjusted risk of multimorbidity in the most deprived areas was 1.36 (95% CI, 1.33 1.38) in women, and 1.29 (95% CI, 1.27-1.31) in men, with a women-to-men ratio of RRs of 1.05 (95 % CI, 1.02-1.08).

CONCLUSION: Multimorbidity is more common in individuals with lower socioeconomic status, and men have a higher age-adjusted risk than women. The association between area-based deprivation and multimorbidity is stronger in women than men, emphasizing the need for tailored interventions that address both sex and socioeconomic disparities in multimorbidity.