Measuring the minimum clinically important difference in BPH outcome measures.

PURPOSE: To determine the minimum clinically important difference with respect to the different outcome measures used in benign prostatic hyperplasia (BPH) research. MATERIALS AND METHODS: Forty-two patients diagnosed with symptomatic BPH were prospectively recruited from community urology clinics. Patients were asked at follow-up visits to rate their improvement using a self-administrated questionnaire. The improvement score was then compared to the changes from baseline in each of the outcome measures. RESULTS: Maximum and mean flow-rates did not correlate significantly with the patient's improvement measure. The Boyarsky score correlated best with the patient's grading of overall improvement (R=.507, p<.001). The mean change in Boyarsky symptom score for patients with a small improvement was 3.23 (sd=3.52).