50-percent decrease in severity a meaningful endpoint in chronic pelvic pain

A clinically meaningful endpoint for future therapeutic trials in urological chronic pelvic pain syndrome is a decrease of 30‒50 percent in pelvic pain severity, suggests a study. Clinically significant differences for urinary symptom severity are more appropriately defined separately for males and females.

“Symptom heterogeneity in interstitial cystitis/bladder pain syndrome and chronic prostatitis/chronic pelvic pain syndrome, collectively termed urological chronic pelvic pain syndrome, has resulted in difficulty in defining appropriate clinical trial endpoints,” the investigators said.

Individuals with urological chronic pelvic pain syndrome participated in this study. Using regression and receiver operating characteristic curves, the investigators defined clinically important differences by associating changes in pelvic pain severity and urinary symptom severity over 3 to 6 months, with marked improvement on a global response assessment.

In addition, they assessed and examined clinically important differences for absolute and percent change, as well as by sex-diagnosis, presence of Hunner lesions, pain type, pain widespreadness, and baseline symptom severity.

An absolute change of ‒4 was deemed clinically relevant in pelvic pain severity in patients, but clinically important difference estimates varied by pain type, Hunner lesion presence, and baseline severity. In terms of pelvic pain severity, clinically important difference estimates for percent change ranged from 30 percent to 50 percent and were more consistent across subgroups.

Notably, the absolute change urinary symptom severity clinically important difference was ‒3 and ‒2 for female and male participants with chronic prostatitis/chronic pelvic pain syndrome only, respectively. Larger symptom reductions were needed for those with higher baseline severity to attain improvement.

“Estimated clinically important differences had lower accuracy among participants with low baseline symptoms,” the investigators said.