Infliximab versus ciclosporin in steroid resistant acute severe ulcerative colitis: a model-based cost-utility analysis of data from CONSTRUCT pragmatic trial.

Abstract

There is limited evidence in the literature on the long-term effectiveness and cost-effectiveness of treatments for Acute Severe Ulcerative Colitis (ASUC). The study aimed to perform decision analytic model-based long-term cost-utility analysis (CUA) of infliximab versus ciclosporin for steroid-resistant ASUC investigated in CONSTRUCT pragmatic trial. A decision tree (DT) model was developed using two-year health effect, resource use and costs data from CONSTRUCT trial to estimate relative cost-effectiveness of two competing drugs from the United Kingdom (UK) National Health Services (NHS) perspective. Using short-term trial data, a Markov model (MM) was then developed and evaluated over further 18 years. Both DT and MM were combined to investigate cost-effectiveness of infliximab versus ciclosporin for ASUC patients over 20-year time horizon, with a rigorous multiple deterministic and probabilistic sensitivity analyses to address uncertainty in results. The decision tree mirrored trial-based results. Beyond 2-year trial follow-up, Markov model predicted a decrease in colectomy rate, but it remained slightly higher for ciclosporin. NHS costs and quality adjusted life years (QALYs) over base-case 20 year time horizon were £26,793 and 9.816 for ciclosporin and £34,185 and 9.106 for infliximab, suggesting ciclosporin dominates infliximab. Ciclosporin had 95% probability of being cost-effective at a willingness-to-pay (WTP) threshold value up to £20,000. Using data from a pragmatic RCT, the cost-effectiveness models produced incremental net health benefit in favour of ciclosporin relative to infliximab. Results from long-term modelling indicated that ciclosporin remains dominant compared with infliximab for the treatment of NHS ASUC patients, however, these need to be interpreted cautiously. CONSTRUCT Trial registration number ISRCTN22663589; EudraCT number: 2008- 001968-36 (Date 27/08/2008).