Purpose: Dysmenorrhea refers to the experience of pelvic pain/cramps experienced by women around or during menstruation. A literature review indicated that no existing patient-reported outcome measure was adequate to support labeling claims in dysmenorrhea. Therefore, this study aimed to develop a new measure that could be used as a primary end point in dysmenorrhea clinical trials. Methods: Open-ended interviews were conducted with 52 dysmenorrhea patients, including a subset of 12 women with a comorbid pelvic pain condition (PPC). Verbatim transcripts were analyzed thematically. The findings were used to generate draft items for an electronic diary (eDiary). A further 24 dysmenorrhea patients pilot-tested the eDiary for 1-5 weeks and completed cognitive interviews to assess content validity. Revisions to the eDiary were implemented based on the findings. Results: In the first set of interviews, 51 women (98 %) spontaneously reported pain/cramps in or around the pelvic region (abdomen, lower back, legs/upper thighs, and vaginal area). Pain experiences reported were similar across dysmenorrhea and dysmenorrhea plus PPC subgroups, except that the pelvic pain among PPC patients occurred throughout the month, not only during menstruation. All participants described the detrimental impact of dysmenorrhea on health-related quality of life. Conclusions: The eDiary was conceptually comprehensive and easy to complete/understand during cognitive debriefing. The resulting nine-item diary included assessment of: menstrual bleeding severity; pain severity; use of analgesics; impact on work/school, physical activities, social and leisure activities, and sleep. Psychometric validation is ongoing and will assess the reliability, validity, and responsiveness of the eDiary as a comprehensive dysmenorrhea assessment
