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

Background 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. Methods 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. 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. Conclusion 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. Trial registration CONSTRUCT Trial registration number ISRCTN22663589; EudraCT number: 2008- 001968-36 (Date 27/08/2008).