Worldwide prevalence of dysmenorrhea: a systematic review and meta-analysis across 70 countries.

Dysmenorrhea is menstrual pain of uterine origin that can be classified as primary (PD) or secondary (SD). The worldwide prevalence of dysmenorrhea has been estimated in previous systematic reviews; however, these results are often limited by the focus on specific populations, or the inclusion of studies published only in English. Therefore, we estimated the worldwide prevalence of dysmenorrhea of both PD and SD. In this systematic review, we searched 6 databases for studies reporting the prevalence of dysmenorrhea published between 2000 and 2024, without language restriction. The risk of bias of the included studies was assessed using the Joana Briggs Institute tool. Meta-analysis was conducted in Rstudio. The heterogeneity within meta-analyses was evaluated by I2 statistics. Subgroup analyses were performed by PD, SD, age group, and study setting to investigate sources of heterogeneity as well. The certainty of evidence was assessed using GRADE modified for prevalence studies. A total of 336 studies were included in this systematic review. Most of them were conducted in Asia (49.4%). The pooled worldwide prevalence of dysmenorrhea, PD, and SD were 71.3% (95% CI 68.7%-73.8%), 73% (95% CI 68%-78%), and 35% (95% CI 19%-56%), respectively. Dysmenorrhea was more prevalent in Central America (89.6%), Sri Lanka (97.7%), among adults (73.3%), and at universities (78.4%). All subgroup analyses showed high heterogeneity (I2 = 99.5%-100%) with very low certainty of evidence. This high prevalence of dysmenorrhea worldwide highlights the need for healthcare providers and public health organizations to address menstrual pain's global burden.