Urethral Stricture Symptom and Impact Measure (USSIM) Validation Study.

Objective: To create and validate a disease-specific Patient-Reported Outcome Measure (PROM) derived from the patient voice for men with a urethral stricture disease.

Methods: We previously performed and published a qualitative assessments to construct a disease-specific PROM for urethral stricture disease. Psychometric evaluations were done on the developed final form using both the preoperative and postoperative data. We assess instrument internal consistency, validity, sensitivity to change, and test-retest reliability.

Results: Three dimensions were suggested by the parallel analysis. All items loaded on one general factor and two group factors. Based on a review of clinical meaning, the remaining 10 items relating to urinary or sexual functions were retained in the final form with each item having 5 possible responses. The density plot for the USSIM total score revealed a significant skew toward improved function following surgery. Cronbach's alpha among the 10 items was 0.8 (95% 0.75-0.84) for the preoperative cohort and 0.82 (95% CI: 0.78-0.86) for the postoperative cohort, indicating good internal consistency. Overall, the final USSIM is adequate to discriminate patients who did better or worse following surgery. The intraclass correlation coefficient for USSIM score was 0.74 indicating moderate to good test-retest reliability.

Conclusions: The Urethral Stricture Symptom and Impact Measure possesses strong measurement properties that are representative for use in men with a urethral stricture. We propose use of this instrument in the preoperative and postoperative setting.