Physical activity for primary dysmenorrhea: A systematic review and meta-analysis of randomized controlled trials

Background: Primary dysmenorrhea is cramping abdominal pain associated with menses. It is prevalent, affects quality of life, and can cause absenteeism. Although evidence based medical treatment options exist, women may not tolerate these or may prefer to use non-medical treatments. Physical activity has been recommended by clinicians for primary dysmenorrhea since the 1930s, but its effectiveness is still unknown. Objective: We sought to determine the effectiveness of physical activity for the treatment of primary dysmenorrhea Data sources: Systematic literature searches of multiple databases were performed, including searches for grey literature, from database inception to 24th May 2017. Google searches and citation searching of previous reviews was also conducted. Study eligibility criteria: Studies were selected using predefined selection criteria as specified in the registered protocol. Randomized controlled trials were included if they assessed physical activity interventions against any comparator over at least two menstrual cycles and assessed pain intensity or pain duration as an outcome. Study selection was performed by two independent reviewers at both the title/abstract and full text level. Study appraisal and synthesis methods: Study quality was assessed by two independent reviewers using the Cochrane Risk of Bias Tool. Random effects meta-analyses for pain intensity and pain duration were conducted, with pre-specified subgroup analysis by type of physical activity intervention. Results: Searches identified 15 eligible randomized controlled trials; totalling 1681 participants. Data from 11 studies was included in the meta-analyses. Pooled results demonstrated significant effect estimates for physical activity versus comparators for pain intensity ( 1.89cm on Visual Analogue Scale, 95% confidence interval 2.96 to 1.09) and pain duration ( 3.92 hours, 95% confidence interval 4.86, to 2.97). Heterogeneity for both these results was high and only partly mitigated by subgroup analysis. Primary studies were of low or moderate methodological quality but results for pain intensity remained stable during sensitivity analysis by study quality. Conclusion: Clinicians can inform women that physical activity may be an effective treatment for primary dysmenorrhea but there is a need for high quality trials before this can be confirmed.