Cost-effectiveness of biological therapy for Crohn's disease: Markov cohort analyses incorporating United Kingdom patient-level cost data.

Summary Background  Anti-TNF-alpha agents for Crohn's disease (CD) have good clinical efficacy but high acquisition cost compared to rival drugs. Aim  To assess the cost-effectiveness of infliximab and adalimumab for Crohn’s disease from the perspective of the UK NHS, incorporating recent trial and observational data. Methods  Lifetime Markov analyses constructed to simulate quality-adjusted life-years (QALYs) and costs. CD was represented by four health-states representing: Full response, partial response, nonresponse, surgery and death. The course of CD under standard care was based on the Olmsted county cohort. Systematic review identified ACCENT I (infliximab) and CHARM (adalimumab) as sources for efficacy data. We modelled an intention-to-treat strategy for biologics including surgical rates based on observational data, cost estimates from our UK dataset and utilities from an algorithm converting CDAI to EQ-5D utilities. Results  The incremental cost-effectiveness ratios (ICERs) compared to standard care for 1-year of treatment with infliximab or adalimumab were £19 050 and £7190 per QALY gained, respectively. Lifetime therapy was dominated by standard care. Analyses over shorter time horizons, matched to treatment duration, resulted in unfavourable ICERs. Conclusion  The model suggests acceptable ICERs for biological agents when considering a lifetime horizon with periods of up to 4 years continuous therapy. As with all economic evaluations, the results may not be generalizable beyond the perspective of analysis.