USING VALUE OF INFORMATION IN THE DEVELOPMENT OF CLINICAL TRIALS: A CASE STUDY OF STATIN THERAPY IN PATIENTS WITH RHEUMATOID ARTHRITIS
Nick J. Bansback, MSc1, Roberta Ara2, Sue Ward2, Aslam H. Anis, PhD3, and Hyon Choi, MD3. (1) St. Paul's Hospital, Vancouver, BC, Canada, (2) University of Sheffield, Sheffield, United Kingdom, (3) University of British Columbia, Vancouver, BC, Canada
Purpose: Increasingly, the cost-effectiveness of an intervention is becoming a fourth hurdle in its development (along with quality, safety and efficacy). If an intervention is considered an inefficient use of healthcare resources then its developmental costs could have been spent better elsewhere. While decision analysis can examine if the intervention is expected to be cost-effective based on existing evidence; value-of-information (VoI) analysis can be used to determine if additional research on the intervention itself is cost-effective. Uptake of VoI has been slow, partly since it is has mostly been performed after phase III studies have been undertaken, when justifying further research to policy makers is difficult. We apply VoI methods to the case of statins in rheumatoid arthritis (RA), recently studied in a proof of concept study, for which a multi-centre study is now planned. Methods: A decision model was developed to examine the long term costs and benefits (on lipid profiles; subsequent risk of coronary events (eg CHD); and RA activity (DAS/HAQ)) of adding statins to conventional therapy. Uncertainty analysis was performed by assigning joint probability distributions to each parameter. Partial EVPI was undertaken using the two-level method. Results: Using a 10yr time horizon, and a US perspective, the incremental cost effectiveness of statin therapy was uncertain (95%CI ranged from $8k to >$100k per QALY gained). Whether this is cost-effective depends on what is considered reasonable additional cost for additional benefit. Assuming the policy would entail all patients with RA (prev=1%) receiving statins with their conventional DMARD therapy, in the US the total EVPI was estimated to be up to $2 billion per year. Findings (partial EVPI) indicate pivotal areas of uncertainty are: longer term benefit of statin therapy and improvement of DAS and its relationship with health utility. Conclusions: Implementation of a concomitant statins therapy for patients with RA could cost up to $3 billion in the US per annum (statin costs alone). Whether the policy is cost-effective is uncertain. Our study finds the impending trial of statins to be economically warranted. However it must be designed to be longer than 6 months and measure health utilities if it is going to improve the policy decision uncertainty.