Benign Prostatic Hyperplasia Specific Health Status Measures in Clinical Research: How Much Change in the American Urological Association Symptom Index and the Benign Prostatic Hyperplasia Impact Index is Perceptible to Patients?

Abstract
We assessed the relationship between changes in scores for the American Urological Association (AUA) symptom index and benign prostatic hyperplasia (BPH) impact index with patient global ratings of improvement in a large Veterans Affairs trial comparing different pharmacological therapies for BPH. The primary analyses compared absolute score changes from baseline with global ratings of improvement at 13 weeks for 1,218 men. Subjects who rated themselves as being slightly improved had a mean decrease in AUA symptom index and BPH impact index scores of 3.1 and 0.4 points, respectively. However, the baseline scores strongly influenced this relationship. These data provide guidance for investigators using the AUA symptom index and BPH impact index as outcome measures.