Treatment for Mixed Urinary Incontinence: Mid-urethral Sling vs. Botox A

ABSTRACT Mixed urinary incontinence (MUI), defined as the presence of both stress urinary incontinence and urgency urinary incontinence, is a challenging condition for which clinicians frequently use multiple sequential treatments that have undergone limited head to head comparison in rigorous clinical trials. Mid-urethral Sling vs. Botox A (MUSA) is a randomized 2-arm clinical trial for women who have at least moderate bother from both stress and urgency incontinence and who have failed one or more conservative treatments. The primary objective is to estimate the effect of 100 units of intradetrusor injections of Botulinum toxin A (Botox A ®) compared to mid-urethral sling surgery for the treatment of MUI in 110 women. Participants in the Botox A arm may receive one additional injection of 100 units Botox A between 3 months and 6 months after the initial injection if they have persistent urgency incontinence symptoms and meet the safety criteria. The primary outcome for this trial is the change in severity of MUI symptoms which will be measured at 6 months using the Urogenital Distress Inventory. Secondary objectives include identifying predictors of treatment failure and cost-effectiveness of treatments. Safety and adverse events data will also be collected. At the completion of this study, we will better understand whether a surgical treatment that focuses on the urgency component (Botox A) is superior to a surgical treatment that focuses on the stress component (midurethral sling). The trial will provide clinically useful information for two treatments that are widely used to treat MUI but for which evidence-based data are not available.