The effect of body mass index on retropubic midurethral slings

Abstract

Analyzing surgical databases uses "real-life" outcomes rather than highly selected cases from randomized controlled trials. Retropubic midurethral slings are a highly effective surgical treatment for stress urinary incontinence; however, if modifiable patient characteristics alter outcomes, thereby rendering treatments less effective, patients should be informed and given the opportunity to change that characteristic. The aim of this study was to evaluate the effect of body mass index on patient-reported outcome measures by analyzing midurethral slings from the British Society of Urogynaecology database. The British Society of Urogynaecology approved analysis of 11,859 anonymized midurethral slings from 2007 to 2016. The primary outcome of this retrospective cohort study was to assess how body mass index affects patient-reported outcome measures. Outcomes were assessed at 6 weeks, 3 months, 6 months, or 12 months after surgery, depending on local arrangements. Outcomes were compared by body mass index groups using χ2 tests. As BMI increased, Patient Global Impression of Improvement (PGI-I) scores declined. Women with a normal body mass index (18 to <25) reported feeling better in 91.6% of cases compared to lower rates in BMI groups >30 (87.7-72%) (P < .001). Patient-reported outcome measures for stress urinary incontinence inversely correlated with body mass index, with 97% of women with normal body mass index stating that they were cured/improved compared to women in higher body mass index groups (84-94%) reporting lower rates (P < .005). Patient-reported outcome measures for overactive bladder show that as body mass indexincreases, patients reported higher rates of worsening symptoms (P< .05). There were higher rates of perforation at the low and high extremes of body mass index. Our results suggest increased body mass index is associated with poorer outcomes after midurethral sling surgery, and that patients should be given the opportunity to change their body mass index. These data could help to develop a model to predict personalized success and complication rates, which may improve shared decision making and give an impetus to modify characteristics to improve outcomes.