Background Epidemiological literature suggests that chronic pain (CP) affects more females than males from puberty onwards, but it is unclear how sex differences change across different phases of the life-course because of lack of robust data from certain phases, like the mid-life. Mid-life is a sensitive period during which social and biological changes occur which can affect the health of people of both sexes distinctly.

Methods We conducted a systematic review of the existing literature to investigate CP prevalence by sex and the difference in CP between sexes at mid-life (age 40–60). The literature search was conducted on MEDLINE, EMBASE, AMED and PSYCHinfo. The findings are reported in a narrative synthesis following the Social Research Council Methods Programme guidelines. Random effects meta-analysis was used to estimate the relative risk (RR) for sex difference in CP.

Results Eighteen eligible articles provided information on CP prevalence and demonstrated substantial variation in prevalence for both sexes. All but two studies found a higher prevalence of CP in females than in males. Based on a meta-analysis of seven studies, the overall RR was 1.19 (95% CI 1.13–1.26) for females compared with males with no evidence of heterogeneity. In subgroup analyses, the RR was lower for generic CP (1.19, 95%CI 1.13–1.25) than for fibromyalgia (FM) (3.13, 95%CI 1.22–8.04) although there were only two FM studies of small sample size.

Conclusion Our review found that females are more likely to experience CP at mid-life and that there is little heterogeneity in the sex difference despite great variation in prevalence. The sex difference may be greater for FM but larger studies of FM are needed to provide more precise estimates.