Smartphone app-delivered self-acupressure resulted in a reduction of menstrual pain compared to usual care only. Effects were increasing over time, and adherence was good. Future trials should include comparisons with other active treatment options.

BACKGROUND: Primary dysmenorrhea is common among women of reproductive age. Nonsteroidal anti-inflammatory drugs and oral contraceptives are effective treatments, although the failure rate is around 20-25%. Therefore additional evidence-based treatments are needed. In recent years, the use of smartphone applications (apps) has increased rapidly and may support individuals in selfmanagement strategies. OBJECTIVE: We aimed to investigate the effectiveness of app-based selfacupressure in women with menstrual pain. MATERIALS AND METHODS: A two-armed randomized pragmatic trial was conducted from December 2012 to April 2015 with recruitment until August 2014 in Berlin, Germany, among women aged 18-34 years with self reported cramping pain 6 on a numeric rating scale (NRS) for the worst pain intensity during the previous menstruation. After randomization women performed either app-based self-acupressure (n=111) or followed usual care only (n=110) for six consecutive menstruation cycles. The primary outcome was the mean pain intensity (NRS 0-10) on the days with pain during the third menstruation. Secondary outcomes included worst pain intensity during menstruation, duration of pain, 50% responder rates (reduction of mean pain by at least 50%), medication intake, sick leave days and body efficacy expectation assessed at the 1(st), 2(nd), 3(rd), and 6(th) menstruation cycle. RESULTS: We included 221 women (mean age 24.0 (sd 3.6) years). The mean pain intensity difference during the third menstruation was statistically significant in favor for acupressure (acupressure: 4.4 95% CI [4.0; 4.7]; usual care 5. 0 [4.6; 5.3]; mean difference -0.6 [-1.2; -0.1], p=0.026). At the sixth cycle, the mean difference between the groups -1.4 [-2.0; -0.8] (p<0.001) reached clinical relevance. At the third and sixth menstruation cycle, responder rate was 37% and 58% respectively in the acupressure group in contrast to 23% and 24% in the usual care group. Moreover, the worst pain intensity (group difference -0.