Kelly L Kantartzis1, Jonathan P Shepherd. 1. From the Division of Urogynecology, Department of Obstetrics, Gynecology,and Reproductive Sciences, Magee Womens Hospital, University of Pittsburgh School of Medicine, Pittsburgh, PA.
Abstract
OBJECTIVE: Sacral neuromodulation with InterStim can be performed with staged implants or peripheral nerve evaluation followed by a combined stage I/II procedure. In both, unilateral or bilateral leads can be placed for the testing phase. Our objective was to determine the cost-effectiveness of these strategies in patients with refractory overactive bladder. METHODS: A cost-effectiveness model compared 6 strategies, namely, unilateral and bilateral testing for both stage I and peripheral nerve evaluation, combined stage I/II, and no treatment. Costs were derived from a societal perspective using Medicare physician fee schedules and published studies. Quality-adjusted life-years (QALYs) were assigned using utility values. Results were reported using incremental cost-effectiveness ratios. Model robustness was assessed using probabilistic sensitivity analysis. Monte Carlo analysis sampled statistical distributions for each variable to examine the effects of varying all values simultaneously. RESULTS: No InterStim treatment was the least expensive but also the least effective option. Unilateral and bilateral stage I were the only cost-effective options with incremental cost-effectiveness ratios of $3533 and $7600, respectively. Because bilateral stage I was more effective, it is preferred. Probabilistic sensitivity analysis showed bilateral stage I was most likely to be cost-effective at willingness-to-pay thresholds greater than $6000 per QALY. At lower thresholds, no treatment was more economically acceptable. CONCLUSIONS: Bilateral and unilateral stage I lead placement were the only cost-effective strategies. Bilateral stage I was preferred due to greater effectiveness. In probabilistic sensitivity analysis, bilateral stage I was the most likely cost-effective strategy at all willingness-to-pay thresholds greater than $6000 per QALY confirming model robustness.
OBJECTIVE: Sacral neuromodulation with InterStim can be performed with staged implants or peripheral nerve evaluation followed by a combined stage I/II procedure. In both, unilateral or bilateral leads can be placed for the testing phase. Our objective was to determine the cost-effectiveness of these strategies in patients with refractory overactive bladder. METHODS: A cost-effectiveness model compared 6 strategies, namely, unilateral and bilateral testing for both stage I and peripheral nerve evaluation, combined stage I/II, and no treatment. Costs were derived from a societal perspective using Medicare physician fee schedules and published studies. Quality-adjusted life-years (QALYs) were assigned using utility values. Results were reported using incremental cost-effectiveness ratios. Model robustness was assessed using probabilistic sensitivity analysis. Monte Carlo analysis sampled statistical distributions for each variable to examine the effects of varying all values simultaneously. RESULTS: No InterStim treatment was the least expensive but also the least effective option. Unilateral and bilateral stage I were the only cost-effective options with incremental cost-effectiveness ratios of $3533 and $7600, respectively. Because bilateral stage I was more effective, it is preferred. Probabilistic sensitivity analysis showed bilateral stage I was most likely to be cost-effective at willingness-to-pay thresholds greater than $6000 per QALY. At lower thresholds, no treatment was more economically acceptable. CONCLUSIONS: Bilateral and unilateral stage I lead placement were the only cost-effective strategies. Bilateral stage I was preferred due to greater effectiveness. In probabilistic sensitivity analysis, bilateral stage I was the most likely cost-effective strategy at all willingness-to-pay thresholds greater than $6000 per QALY confirming model robustness.