Sex differences in multimorbidity: a systematic review and meta-analysis

Emerging evidence suggests that sex and gender may influence the development, expression, and impact of multimorbidity through a range of mechanisms. This review aimed to examine the differences between women and men in the prevalence, risk factors, and patterns of multimorbidity, and sex differences regarding the impact of multimorbidity on health outcomes. A systematic literature search was conducted in Ovid Medline and Embase from inception until June 2025. Studies in human beings which reported data separately for women and men related to multimorbidity were included. Where possible, estimates from the included studies were pooled using inverse-variance weighted meta-analysis. Where available, the sex differential was quantified as the women-to-men ratio of prevalence, relative risks, hazard ratios or odds ratios. This review is registered at PROSPERO, CRD42024553043. This review identified 37 studies of 5,828,856 individuals (60% women) from 24 countries. We summarised the findings on sex differences according to: (1) prevalence of multimorbidity, (2) risk factors for multimorbidity, (3) patterns of multimorbidity, and (4) the impact of multimorbidity on health outcomes. The pooled multimorbidity prevalence in the 31 general population studies were 0.45 (95%CI 0.35–0.56) in women and 0.39 (95%CI 0.30–0.50) in men, pooled women-to-men prevalence ratio for multimorbidity was 1.12 (95%CI 1.02–1.23). In studies in populations with an index disease, the prevalence of multimorbidity was much higher: 0.83 (95%CI 0.63–0.93) in women and 0.82 (95%CI 0.48–0.96) in men. There were limited studies examining sex differences in the patterns and risk factors for multimorbidity, and on the impact of multimorbidity on outcomes. Our systematic review reveals a higher prevalence of multimorbidity in women than men. The increased likelihood of multimorbidity in women compared to men is a complex issue influenced by multiple factors and highlights the need for further research on this topic.