IHESA Interstim Health Economic Spanish Assessment Shangai March 2006 ISPOR, 2º Asia- Pacific Congress José-Manuel Rodriguez Barrios BPharm, MPH, MSc, MPhil Health Economics & Reimbursement Manager Medtronic Ibérica 1
Study Participants Navarro Albert, and Muñoz Arantxa. Hospital Mutua de Terrassa, Terrassa, Barcelona, Spain Brosa Max. Oblikue Consulting Gisbert Ramon. Economics Department Vic University Rodriguez JM, Serrano-Contreras D. Health Economics & Reimbursement Medtronic Iberia Minda K, Health Economics & Reimbursement Medtronic SARL Tolochenatz Switzerland 2
Fecal incontinence Fecal incontinence (FI) can be one of the most psychologically and socially debilitating conditions in an otherwise healthy individual (Nelson, 2004) It can lead to social isolation, loss of self-esteem and self-confidence, and depression Prevalence in Spain has been estimate between 2.2%-15% (Minguez M, 2004) Incidence rates reach 2.2% Spanish general population (Minguez M, 2004) Etiology is not clear and depends on one or a combination of several factors can lead to the inability to control passage of stool or flatus Mínguez M, Benages A. Calidad de vida en los pacientes con incontinencia anal. Gastroenterol Hepatol 2004;27(Supl 3):39-48. Nelson RL: Epidemiology of fecal incontinence. Gastroenterology 126:S3-S7, 2004 3
Fecal incontinence. Current management. The goal of treatment for patients with FI is to restore continence and to improve the QoL Specific treatment of fecal incontinence may be considered under the following categories: Treatments: o Non surgical procedures: Dietary advice Pharmacologic therapy Biofeedback therapy o Surgical procedures: Sphincteroplasty Graciloplasty Sacral Nerve Stimulation Colostomía 4
Economic model. Objectives MAIN To assess the clinical and economic consequences of adding Interstim in the management of fecal incontinence in Spain. SPECIFIC To build up a decision analytic tool to model the costs and effects (Utilities) associated to two alternative scenarios in the management of fecal incontinence: two therapeutic scheme with and without Interstim. To use the economic model to estimate the expected budget impact of extending/introducing the use of Interstim in Spain. To develop an interactive version of the economic model to provide with a tool useful in the local adaptation of the results. 5
Economic model. Methods Type of analysis: retrospective cost-effectiveness using a decision tree model with an attached Markov model to account for mid/long term outcomes The whole model as developed in EXCEL Costs: only medical direct costs are considered Effects: outcomes of comparators are translated into QALYs Data sources: literature review and expert opinion for both clinical and economic parameters Time horizon: 5 years Discount rate: both costs and effects are discounted at a 3% annual rate Point of view: that of the NHS 6
Economic model. Comparators The study is divided in two sub analysis for two patient groups SDAS (Structural Deficient Anal sphincter) IAS (Intact Anal Sphincter) For each group of patients a specific model was developed, in which two alternative scenarios are compared: Therapeutic scheme without interstim Therapeutic scheme with interstim In both cases, the analysis begins when conservative treatment has failed to control patients fecal incontinence. 7
Treatment algorithm of FI Conservative therapy Success SDAS IAS Success Sphincteroplasty Sacral nerve stimulation Sacral nerve stimulation Artificial anal sphincter / Dynamic graciloplasty Success Success Artificial Anal sphincter / Dynamic graciloplasty Colostomy 8
Economic model. Model structure (SDAS) M 9
Economic model. Model structure (IAS) IF-IAS M 10
Markov Sub model Patients can delay their entrance to Markov model until 2 years (patients in which the firsts 3 treatment fail) For every therapy we have effectiveness rates at long term (5 yrs.) We project the results until 7 years time horizon Markov sub model We have to assume effectiveness rates for the last two years for patients successfully treated at first and second line 11
- Jarrett ME, Mowatt G, Glazener CM, Fraser C, Nicholls RJ, Grant AM, Kamm MA: Systematic review of sacral nerve stimulation for faecal incontinence and constipation. Br.J.Surg. 91:1559-1569, 2004 - Expert opinion 12
Resource Uses Data 13
Other parameters 14
Cost-effectiveness results (SDAS patients) Patients in the Interstim scenario have a gain around 0,314 SFY at an incremental cost of 4.217 /SFY. The incremental cost per QUALY in SDAS patients is 22.194 /QUALY what means that introduction of Interstim in the management of IF in Spain is an efficient therapy SFY: Symptom Free years QALYs: Quality Adjusted Life Years 15
Cost-effectiveness results (IAS patients) Patients in the Interstim scenario have a gain around 0,34 SFY at an incremental cost of 3.074 /SFY. The incremental cost per QUALY in IAS patients is 16.179 /QUALY what means that introduction of Interstim in the management of IF in Spain is an efficient therapy SFY: Symptom Free years QALYs: Quality Adjusted Life Years 16
Cost-effectiveness: Probabilistic analysis SDAS (1.000 simulations) All the simulations showed consistent results 17
Cost-effectiveness: Probabilistic analysis IAS (1.000 simulations) All the simulations showed consistent results 18
Acceptability curve Assuming the threshold considered as efficient therapy in Spain (30.000 /AVAC ) the figure shows that 97% of the simulations in SDAS an 80% in IAS patients become bellow this rate 19
Budget impact main assumptions 20
Budget impact results Introducing Interstim in the management of FI can be carried out at a reasonable incremental cost, representing an incremental from 0,7% to 1,8% in the management of FI 21
Economic model. Limitations Lack of evidence for effectiveness figures, especially in the long term Main model assumptions are based on expert opinion QALYs are estimated using utility values associated to urinary incontinence patients (published data) Results are very sensitive to different approaches to timehorizon definition 22
Economic model. Conclusions Surgical management of FI including Interstim in the therapeutic scheme is a cost-effective option when comparing with Spain Cost-effectiveness threreshold The budget impact analysis show that the introduction of Interstim in the management of FI in the therapeutic scheme in Spain can be performed at a reasonable cost Sacristan JA, Oliva J, Del Llano J, Prieto L, Pinto JL. What is an efficient health technology in Spain?. Gac.Sanit. 2002; 16:334-343. 23
Methodological issues To describe natural disease history decision tree was selected as the clearest method, but chronic and repetitive IF states requires a Markov approach. PSA was carried out with all parameters ranges from the model. A Monte Carlo Simulation analysis was performed with a 1000 patients cohort to display C-E plane and acceptability curves for SDAS and IAS patients. Beta distribution was used for probabilities and Lognormal distribution for model costs using updated recommendations Micro costing strategy to assign costs for both, the BIA and the Costutility model. Briggs AH, Goeree R, Blackhouse G, O'Brien BJ. Probabilistic analysis of cost-effectiveness models: choosing between treatment strategies for gastroesophageal reflux disease. Med.Decis.Making 2002; 22:290-308. Claxton K, Schupher M, McCabe C, Briggs A, Akehurst R, Buxton M et al. Probabilistic sensitivity analysis for NICE technology assessment: not an optional extra. Health Economics 2005; 14:339-347. 24