Relationships Among Participant International Prostate Symptom Score, Benign Prostatic Hyperplasia Impact Index Changes and Global Ratings of Change in a Trial of Phytotherapy in Men with Lower Urinary Tract Symptoms

Purpose: We related changes in American Urological Association symptom index scores with bother measures and global ratings of change in men with lower urinary tract symptoms who were enrolled in a saw palmetto trial. Materials and Methods: To be eligible for study men were 45 years old or older, and had a peak uroflow of 4 ml per second or greater and an American Urological Association symptom index score of 8 to 24. Participants self-administered the American Urological Association symptom index, International Prostate Symptom Score quality of life item, Benign Prostatic Hyperplasia Impact Index and 2 global change questions at baseline, and at 24, 48 and 72 weeks. Results: In 357 participants global ratings of a little better were associated with a mean decrease in American Urological Association symptom index scores from 2.8 to 4.1 points across 3 time points. The analogous range for mean decreases in Benign Prostatic Hyperplasia Impact Index scores was 1.0 to 1.7 points and for the International Prostate Symptom Score quality of life item it was 0.5 to 0.8 points. At 72 weeks for the first global change question each change measure discriminated between participants who rated themselves at least a little better vs unchanged or worse 70% to 72% of the time. A multivariate model increased discrimination to 77%. For the second global change question each change measure correctly discriminated ratings of at least a little better vs unchanged or worse 69% to 74% of the time and a multivariate model increased discrimination to 79%. Conclusions: Changes in American Urological Association symptom index scores could discriminate between participants rating themselves at least a little better vs unchanged or worse. Our findings support the practice of powering studies to detect group mean differences in American Urological Association symptom index scores of at least 3 points.