To examine the value of adding an urge incontinence question to the AUA Symptom Index (AUASI) among men in the Complementary and Alternative Medicine for Urological Symptoms (CAMUS) trial.
Materials and Methods
CAMUS is a randomized trial of Saw palmetto fruit extract versus placebo among men ≥ 45 years old with an AUASI score ≥ 8 and ≤ 24. Baseline measurements included the AUASI, a question about urge incontinence (UI), the International Prostate Symptom Score Quality of Life (IPSS QOL) question, and the BPH Impact Index (BII). We correlated the items and scales, and examined whether adding the UI question resulted in better prediction of disease-specific health status.
Mean age of the 369 men in CAMUS was 61 and mean baseline AUASI score was 14.6. UI was reported infrequently; about 82% of respondents answered the question “not at all” or “less than 1 time in 5.” UI was significantly correlated with all other AUASI items except for weak stream; the strongest correlation was to urgency (R=0.51, P<.0001). The correlation between AUASI and the AUASI+UI was 0.98 (P<0.0001). In a logistic regression predicting IPSS QOL, adding UI to the AUASI slightly increased discriminating ability (c statistic increased from 0.77 to 0.78, P<0.0001). Similarly, in a linear regression predicting BII scores, adding UI to the AUASI slightly increased predictive ability (R2 statistic increased from 0.22 to 0.26, P<0.0001).
Based on our analysis in the CAMUS population, the value of adding a UI question to the AUASI in terms of predicting bother seemed small at best.
Keywords: Prostatic hyperplasia, urinary incontinence, urge, psychometrics, IPSS