Smartphone apps may be useful to guide and support individuals in self-management strategies. Primary dysmenorrhea is a very common problem for women. With a randomized, pragmatic study the investigators aim to evaluate whether a smartphone app for women with menstrual pain is effective in reducing menstrual pain in 18-34-year-old women with primary dysmenorrhea. For this the investigators compare the complete smartphone app with two control versions of this app. The complete app provides evidence-based self-care information and instructions for self-acupressure in menstrual pain, the control intervention I includes self-care information, but no instructions for self-acupressure, and control intervention II includes instructions for self-acupressure, but no self-care information. The investigators aim to observe 594 women with primary dysmenorrhea over 12 menstruation cycles. The primary outcome is the mean pain intensity on the days with pain during the 6th menstruation after randomization using a numerical rating scale (NRS; 0=no pain; 10=strongest pain imaginable). Women are eligible when they suffer from primary dysmenorrhea, are between 18 and 34 years old, not pregnant and do not plan to be pregnant within the next 12 months.
With a randomized, pragmatic study the effectiveness of a smartphone app for menstrual pain in 18-34-year-old women with primary dysmenorrhea will be investigated.