The interstitial cystitis symptom index and problem index.

OBJECTIVES To develop 2 brief self-administered indices for measuring lower urinary tract symptoms and their impact in patients with interstitial cystitis (IC). METHODS An initial set of questions was developed and evaluated in focus groups. The index was revised, shortened, and validated with patients diagnosed in 3 large urologic practices with experience in interstitial cystitis (N = 45). Controls were recruited from a group of healthy volunteers in a gynecology clinic (N = 67). Internal consistency, construct validity, and test-retest reliability were evaluated. RESULTS The IC symptom index and the IC problem index measure urinary and pain symptoms and assesses how problematic symptoms are for patients with interstitial cystitis. Psychometric performance of both instruments is good, with the symptom index demonstrating excellent ability to discriminate characteristics between patients and controls. CONCLUSION Both indices should be useful in the evaluation and management of patients with IC and should be particularly useful in clinical trials of new therapies for this condition, where reliable, validated, and reproducible outcome measures are critically important.