ResultsOf the 385 eligible participants, 24.2% reported no flares, 22.9% reported one flare, 28.3% reported 2-3 flares, and 24.6% reported ≥4 flares, up to a maximum of 18 during the 11-month follow-up (median incidence rate = 0.13/bi-weekly assessment, range = 0.00-1.00). Pelvic pain (mean = 2.63point increase) and urological symptoms (mean = 1.72) were both significantly worse during most flares (60.6%), with considerable within-participant variability (26.2-37.8%). Flare duration varied from 1 to 150 days (94.3% within-participant variability). In adjusted analyses, flares were more common, symptomatic, and/or longer-lasting in women and in those with worse non-flare symptoms, bladder hypersensitivity, and chronic overlapping pain conditions.
ConclusionIn this foundational flare study, we found that pelvic pain and urological symptom flares were common, but variable in frequency and manifestation. We also identified subgroups of participants with more frequent, symptomatic, and/or longerlasting flares for targeted flare management/prevention and further study.Longitudinal analysis of UCPPS flares ‡ ‡ Adjusted for site, sex, age, average non-flare symptom intensity, bladder hypersensitivity and number of COPCs, as appropriate. § § Seven extrapelvic regions (back, head, right leg, left leg, right arm, left arm and trunk) were created similarly to previous analyses, using data from the Body Pain Inventory.