Tu1425 A COST-EFFECTIVENESS ANALYSIS OF ENDOSCOPIC TREATMENT STRATEGIES FOR WALLED-OFF NECROSIS

Abstract

Direct endoscopic necrosectomy (DEN) has been shown to be a safe and effective approach at treating walled-off necrosis (WON), however, techniques for performing DEN remain heterogeneous with significant morbidity and variable cost. Traditionally, double pigtail stents (DP) have been used for drainage once a collection has been endoscopically debrided. More recently, DEN using a lumen-apposing metal stent (LAMS) has been proposed as an alternative for accessing and draining WON. To assess the cost-effectiveness of two common DEN strategies, using DP or LAMS. We developed a decision analytic state-transition Monte Carlo microsimulation model to simulate the health-related costs (2017 US dollars) and quality-adjusted life-years (QALYs) of the two DEN strategies (DEN-DP vs DEN-LAMS). Patient cohort consisted of 10,000 US males and females with the age ranging from 18 to 100 years old. Patients were followed for up to 10 years after the initial DEN session. In the model, three DPs were used for each DEN-DP session, while one LAMS was deployed for each DEN-LAMS session. If WON persisted after 3 DEN sessions, patients underwent surgical necrosectomy as a salvage therapy. Probabilities of clinical success and complications after the two DEN strategies were derived from published studies. Costs were obtained from the Medicare provider utilization and payment data and expert opinions. Probabilistic sensitivity analysis was performed on all variables to adjust for uncertainties. A one-way sensitivity analysis was performed to determine the effect of varying LAMS cost on the cost-effectiveness outcome. The willingness-to-pay (WTP) threshold was defined at $150,000 per QALY gained. Analysis was performed from a societal perspective. At 10 years, the cumulative costs and QALYs of the DEN-DP and DEN-LAMS were $50,296 and $53,726 and 7.99 and 8.80, respectively. At a WTP of $150,000, DEN using LAMS was more cost effective than DEN using DP with an incremental cost-effectiveness ratio of $2,311 per QALY gained. A cost-effective acceptability curve showed that DEN using LAMS was more cost effective compared to DEN using DP regardless of WTP threshold. A one-way sensitivity analysis performing on a LAMS price range up to $20,000 showed that DEN with LAMS remained a cost- effective strategy compared to LAMS with DP. Direct endoscopic necrosectomy using LAMS is more cost-effective than using double pig tail stents for treating WON, despite considerably higher device cost.