Factors Associated with the Prevalence and Severity of Menstrual-Related Symptoms: A Systematic Review and Meta-Analysis.

This study aimed to identify factors associated with the prevalence and severity of menstrual-related symptoms. The protocol was registered in PROSPERO (CRD42021208432). We conducted literature searches of PubMed and Ichushi-Web and used the Jonna Briggs Institute critical appraisal checklist to assess the quality. Of the 77 studies included in the meta-analysis, significant odds ratios (ORs) were obtained for eight factors associated with primary dysmenorrhea (PD): age ≥ 20 years (OR: 1.18; 95% confidence interval [CI]: 1.04-1.34), body mass index (BMI) < 18.5 kg/m 2 (OR: 1.51; 95% CI: 1.01-2.26), longer menstrual periods (OR: 0.16; 95% CI: 0.04-0.28), irregular menstrual cycle (OR: 1.28; 95% CI: 1.13-1.45), family history of PD (OR: 3.80; 95% CI: 2.18-6.61), stress (OR: 1.88; 95% CI: 1.30-2.72), sleeping hours < 7 h (OR: 1.19; 95% CI: 1.04-1.35), and bedtime after 23:01 (OR: 1.30; 95% CI: 1.16-1.45). Two factors were associated with severity of PD (moderate vs. severe): BMI < 18.5 kg/m 2 (OR: 1.89; 95% CI: 1.01-3.54) and smoking (OR: 1.94; 95% CI: 1.08-3.47). PD severity (mild vs. severe) and prevalence of premenstrual syndrome were associated with BMI < 18.5 kg/m 2 (OR: 1.91; 95% CI: 1.04-3.50) and smoking (OR: 1.86; 95% CI: 1.31-2.66), respectively. The identified risk factors could be utilized to construct an appropriate strategy to improve menstrual symptoms and support women's health.