Psychometric validation of a German language version of a PROM for urethral stricture surgery and preliminary testing of supplementary ED and UI constructs

PURPOSE: To validate a German language version of the patient-reported outcome measurement (PROM) following urethral stricture surgery (USS) in a cohort of men undergoing one-stage buccal mucosa graft urethroplasty (BMGU) for urethral stricture. Furthermore, to explore the responsiveness of erectile function (EF) and urinary incontinence (UI) constructs in the context of this intervention.

METHODS: The USS-PROM captures voiding symptoms (ICIQ-MLUTS) and health-related quality of life (HRQoL) (EQ-5D). To evaluate EF and UI, the IIEF-5 and ICIQ-UI SF were included. Between March 2012 and April 2013, all patients undergoing BMGU at our institution were prospectively enrolled in this study. Psychometric assessment included internal consistency, test-retest reliability, criterion validity and responsiveness.

RESULTS: Ninety-three men completed the USS-PROM before and 3 months after surgery, with 40 (43 %) also completing the USS-PROM 6 months after surgery to assess reliability. Internal consistency: for the ICIQ-MLUTS, Cronbach's α was 0.83. The test-retest intraclass correlation coefficient was 0.94. There was a negative correlation between change in ICIQ-MLUTS total score and change in Q max (r = -0.40). All values exceeded our predefined thresholds. Significant improvements of voiding symptoms and HRQoL demonstrate responsiveness to change (all p values <0.001). While ICIQ-UI scores did not change (p > 0.05), IIEF-5 scores improved significantly (p = 0.048).

CONCLUSIONS: The German language USS-PROM shows similar psychometric properties to the English language version. This instrument can be improved by assessing EF by the use of IIEF-5. Further studies with larger patient cohorts are needed to evaluate the significance of measuring UI in urethroplasty patients.