Which outcome measures should be used in stress urinary incontinence trials?

OBJECTIVE: To review measures used in recent randomised controlled trials (RCTs) evaluating stress urinary incontinence (SUI) treatments and to propose the most relevant outcome measure that should be included in future trials.

MATERIALS AND METHODS: We identified RCTs for SUI interventions published between January 2015 and July 2017. We listed the objective and subjective outcome measures used in eligible trials in the literature search. Using data from our RCT conducted from 2013 to 2016 evaluating pulsed magnetic stimulation for SUI, we analysed the correlation between all measures.

RESULTS: A total of 45 RCTs were included; 28 (62%) involved surgical interventions. The most frequently used objective and subjective measures were the cough stress test and International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form (ICIQ-UI SF), respectively. In all, 24 different validated questionnaires were administered in the 42 studies that used subjective outcome measure. Analyses of measures used in our trial showed that all measures were significantly correlated with each other except for pelvic floor muscle function. The ICIQ-UI SF showed the highest correlation coefficients (0.587-0.733) with all outcome measures.

CONCLUSION: The outcome measures used in recent trials were inconsistent. The ICIQ-UI SF had the highest correlation with all measures in our trial; however, further studies evaluating correlation of measures in other patient cohorts are needed to corroborate our present results. We propose the use of ICIQ-UI SF, as the most relevant outcome measure, in future trials evaluating efficacy of SUI interventions.