Is antibiotic prophylaxis necessary before midurethral sling procedures for female stress incontinence? A decision analysis.

introduction and hypothesisA recent randomized controlled trial (RCT) with and without prophylactic antibiotics (pABX) for midurethral slings (MUS) was terminated early owing to lower than predicted infectious complications in both groups. Adequate power required an unattainable sample size. Because of low infectious risks, omitting pABX may be justified. Since an RCT was not feasible, we aimed to use decision analysis modeling to determine if pABX are necessary for MUS.

methodsWe created a decision analysis model comparing 1-year quality adjusted life years (QALYs) between women who do and do not receive pABX for MUS. The model included complications that might differ depending on whether antibiotics were given, such as allergic reaction to pABX (mild/severe), vulvovaginal candidiasis, urinary tract infections including pyelonephritis, pseudomembranous colitis, wound infection, and mesh erosion. Multiple one-way sensitivity analyses confirmed model robustness.

resultsOne year after MUS, women who did not receive pABX had higher average QALYs than pABX (0.989 vs 0.977). This difference is less than published minimally important differences (MID) for utilities, suggesting that the strategies are comparable. Ultimately, pABX increased some complications and reduced others with an overall minimal effect on outcomes. Very few thresholds were identified, indicating model robustness and strengthening our conclusions.

conclusionsWomen had slightly higher overall QALY when pABX were not given, but not greater than the MID. Since infectious complications are rare, our model suggests that pABX might be an unnecessary precaution because of similar outcomes with and without pABX.