Cost-effectiveness of prophylactic retropubic sling at the time of vaginal prolapse surgery

Prophylactic midurethral sling placement at the time of prolapse repair significantly reduces the risk for de novo stress urinary incontinence, but it is associated with some small but significant morbidities. Because there has not been a standardized approach to midurethral sling utilization, decision analysis provides a method to evaluate the cost and effectiveness associated with varying midurethral sling placement strategies in addressing the risk for de novo stress urinary incontinence.

We aimed to compare the cost effectiveness of the 3 midurethral sling utilization strategies in treating de novo stress urinary incontinence 1 year after vaginal prolapse repair. The 3 approaches are (1) staged strategy in which prolapse repair is done without prophylactic midurethral sling placement, (2) universal sling placement in which prolapse repair is accompanied by prophylactic midurethral sling placement, and (3) selective sling placement in which prolapse repair is accompanied by prophylactic midurethral sling placement only in patients with a positive prolapse-reduced cough stress test.

We created a decision analysis model to compare staged strategy, universal sling placement, and selective sling placement. We modeled probabilities of de novo stress urinary incontinence, patients choosing subsequent midurethral sling surgery for de novo stress urinary incontinence, and outcomes related to midurethral sling placement. De novo stress urinary incontinence rates were determined for each strategy from published data. The likelihood of patients with de novo stress urinary incontinence choosing midurethral sling surgery as their first-line treatment was also determined from the literature, and this scenario was only applied to patients without prophylactic midurethral sling placement at their index prolapse repair. Finally, outcomes related to midurethral sling placement, including recurrent or persistent stress urinary incontinence, voiding dysfunction requiring sling lysis, mesh exposure requiring excision, and de novo overactive bladder requiring medications, were all derived from publicly available data. All midurethral sling placement procedures were assumed to be retropubic. The costs for each procedure were obtained from the 2020 Centers for Medicare & Medicaid Services Physician Fee Schedule or from previous literature with convertion to 2020 equivalent US dollar prices using the Consumer Price Index. The primary outcome was modeled as the incremental cost-effectiveness ratio. We performed multiple 1-way sensitivity analyses to assess model robustness.

The lowest-cost strategy was the staged strategy, which cost $1051.70 per patient, followed by $1093.75 for selective sling placement and $1125.54 for universal sling placement. The selective sling approach, however, had the highest health utility value; therefore, universal sling placement was dominated by selective sling placement because it is both less costly and more effective. When compared with the staged strategy, selective sling placement was cost effective with an incremental cost-effectiveness ratio of $2664 per quality adjusted life-years, meeting the predetermined threshold. In multiple 1-way sensitivity analyses, the variable with the largest effect was the percentage of patients electing to undergo subsequent midurethral sling surgery for de novo stress urinary incontinence after the index surgery. Only when this proportion exceeded 62% did universal sling placement become the cost-effective option because selective sling placement surpassed the predetermined incremental cost-effectiveness ratio threshold and became dominated.

Selective sling placement was the preferred and cost-effective strategy in treating de novo stress urinary incontinence 1 year after vaginal prolapse repair. Surgeons should counsel their patients preoperatively regarding the possibility of de novo stress urinary incontinence after prolapse repair, as well as on the benefits and risks of prophylactic midurethral sling placement surgery.