BERKELEY, CA (UroToday.com) - The O'Leary-Sant Interstitial Cystitis Symptom Index (ICSI) and Problem Index (ICPI) as well at the Wisconsin IC Inventory were evaluated by looking at data derived from a randomized clinical trial conducted by the Interstitial Cystitis Clinical Trials Group. Propert and colleagues studied a group of patients meeting NIDDK criteria for PBS/IC who reported at least moderate pain and frequency. The primary endpoint was a patient-reported global response assessment (GRA) at 24 weeks. Secondary endpoints included the three composite indexes, pain/discomfort and urgency, and 24 hour frequency. Responsiveness was assessed by comparing symptom score changes against response categories defined by the GRA.

Average symptom decreases were two points for the ICSI and ICPI and 6.5 points for the Wisconsin IC inventory. No evidence showed that any of the composite scores were particularly sensitive to change in only one specific area. The correlations among the changes for the 6 outcome measures (3 composite scores and pain, urgency, and frequency) demonstrated good agreement among the 3 composite scores with all correlation coefficients greater than 0.5. All scales moved in concert with the GRA. Among participants who reported "no change" on the GRA, an average improvement of 0.8 points was found on the ICSI, compared to a change of 6.4 points in those reporting "marked improved" on the GRA.

It appears the O'Leary-Sant and Wisconsin IC Inventory are useful secondary outcomes in PBS/IC clinical trials. The GRA lends itself better as a primary endpoint in that it measures overall improvement and is not biased by missing data or subject withdrawal from clinical trials. Withdrawals can be characterized as nonresponders in an intention to treat analysis. As of now, these scales should not be used in the diagnosis of PBS/IC.

Urology, 67:55-59 (January), 2006