Effectiveness of SP6 (Sanyinjiao) acupressure for relief of primary dysmenorrhea symptoms: a systematic review with meta- and sensitivity analyses

We reviewed the available evidence for SP6 (Sanyinjiao) acupressure for the relief of primary dysmenorrhea (PD) symptoms, as well as patients' experiences of this intervention. We searched six relevant databases and gray literature for publications dated up to March 2016. The search yielded 72 potential studies. Six of these studies, contributing a total of 461 participants, were included in this review. The primary outcome was pain intensity. Studies with significant homogeneity were pooled for meta-analysis. Qualitative data and quantitative data not suitable for meta-analysis were presented as a narrative synthesis. The Cochrane criteria demonstrated that the included studies were generally of low quality with a high risk of bias. SP6 acupressure delivered by trained personnel significantly decreased pain intensity immediately after the intervention (effect size = -0.718; CI = -0.951 to -0.585; p = 0.000), and pain relief remained up to 3 h after the intervention (effect size = -0.979; CI = -1.296 to 0.662; p = 0.000). However, patient-administered intervention required multiple monthly cycles to effect pain reduction. SP6 acupressure appears to be effective when delivered by trained personnel for some PD symptoms. Findings suggest that self-administered acupressure shows promise for the alleviation of PD symptoms. High-quality research is needed before conclusive recommendations are proposed.