Caution with Use of the EPIC-50 Urinary Bother Scale: How Voiding Dysfunction Modifies its Performance.

Purpose: We evaluated agreement between patient reported urinary function and bother, and sexual function and bother in patients treated with radical prostatectomy to help inform possible nonfunctional, modifiable mechanisms for patient bother.

Materials And Methods: Patients were recruited from 2011 to 2014 at Washington University, and Brigham and Women's Hospital. Urinary and sexual outcomes were assessed by EPIC-50 (Expanded Prostate Cancer Index Composite-50) before, 5 weeks and 12 months after radical prostatectomy. Spearman rank correlation coefficients and agreement/disagreement categories were used to describe the relation between function and bother.

Results: Despite moderate to good agreement between function and bother (urinary r = 0.51-0.69 and sexual r = 0.65-0.80) discordant groups were observed. In the urinary domain these groups were men disproportionately bothered by function at baseline (16.9%) and 12 months after radical prostatectomy (6.1%) and men less bothered by function 5 weeks (26.8%) and 12 months (9.9%) after radical prostatectomy. Discordant groups in the sexual domain were men less bothered by function at baseline (20.8%), and 5 weeks (21.1%) and 12 months (15.7%) after radical prostatectomy. Splitting the urinary bother scale into 2 subscales, including one for incontinence related bother to complement the urinary function scale which measures only incontinence, and one for voiding dysfunction related bother yielded considerably better agreement (urinary function and incontinence related bother r = 0.78-0.83). Factors contributing to the group less bothered by sexual function were unclear.

Conclusions: When using EPIC-50, investigators should consider splitting the urinary bother scale by the relation to incontinence to prevent distortions of function-bother and comparisons before vs after radical prostatectomy by coexisting voiding dysfunction.