Introduction. Endoscopic placement of stents is the preferred treatment for palliation of obstructive symptoms in non-operative candidates but significant differences in procedure and stent-related costs, patency of stents survival of patients exist. Aim. To determine the cost-effectiveness of two strategies using Polyethylene (PE) stents (PE with replacement on demand; PE with routine exchange every 3 months), as well as uncovered (U-SEMS) and covered self-expandable metal stent (C-SEMS) in the management of distal malignant biliary obstruction. Methods. A Markov model comparing four different initial approaches was designed: (1) PE stent with replacement on demand (PE-D); (2) PE stent changed every 3 months (PE-Q3); (3) U-SEMS or (4) C-SEMS. Probabilities and parameters for distribution were abstracted from randomized controlled trials and imputed to a 12-month time horizon. Effectiveness was calculated as number of occlusion-free months. Procedural and complication-related costs were obtained from the Canadian Institute for Health Information and a Provincial perspective was adopted. A probabilistic cost-effectiveness analysis using Monte Carlo simulations was utilized to obtain a posterior joint distribution for costs and effectiveness. Average and incremental net health benefits, probabilities of cost-effectiveness and value of information were determined across a range of willingness to pay (Rc) values. Results. PE-D has the lowest CE ratio, followed by C-SEMS at an incremental cost-effectiveness ratio (ICER) of $146.64$/month of stent patency. C-SEMS has the lowest CE ratio under the following scenarios: probability of survival at 12 months greater than 83%, ERCP costs higher than $1,282.90, cost C-SEMS less than $1,485.60 and cost ratio between ERCP and C-SEMS greater than 0.4. In the probabilistic analysis, PE-D is the strategy with the highest probability of cost-effectiveness for willingness to pay values lower than $150.60. How / Conclusion. Conditional to the willingness to pay and current Canadian costs, PE-D and C-SEMS are the strategies with the highest probabilities of cost-effectiveness. However, a significant level of uncertainly remains and wrong decisions will occur given the existent information. Acquisition of further knowledge to decrease the uncertainty level may be indicated if it costs less than the opportunity losses.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.84091 |
| Date | January 2005 |
| Creators | Da Silveira, Eduardo |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Epidemiology and Biostatistics.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 002263210, proquestno: AAIMR22783, Theses scanned by UMI/ProQuest. |
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