Methods
ASUC
DISEASE
We used data from 270 ASUC patients in the CONSTRUCT pragmatic study to develop a decision tree and a Markov state-transition model. The study considered the UK National Health Services (NHS) perspective and adopted a cost-utility analysis (CUA) approach. NHS resource usage, including intervention drugs, and their costs captured in the trial were modeled and extrapolated over the long-term study duration. Patients recruited in the trial were 18 years or older who failed to respond to 2–5 days of intravenous hydrocortisone with continuing severe disease. Mean (SD) age of patients at randomisation was 39.3 (15.5) in Infliximab and 39.8 (15.0) in Ciclosporin group, respectively. Patients randomized to infliximab were given 5 mg/kg by intravenous infusion over 2 h at baseline, and again at 2 weeks and 6 weeks after the first infusion, in line with local hospital guidelines. Ciclosporin patients received Sandimmun by continuous infusion continued for up to 7 days if successful, and then switched to twice-daily oral doses. After 12 weeks, all treatment was at the discretion of patient’s physician in the respective hospital. Most of the ciclosporin patients completed their treatment within first 12 weeks but for a number of infliximab patients drug costs continued during the follow up.The study followed the UK NICE’s guide to methods of technology appraisal for economic evaluation and base in British National Formulary (BNF) pricing for valuing both treatment drugs used within the NHS. Infliximab biosimilars are likely to push down drug acquisition costs for local hospitals through commercial negotiations in confidential, however, these costs might not be true representative of actual drug costs of the manufacturer, hence, not been used for economic costing in the study. However, the change in the price for infliximab biosimilars and its potential impact on cost-effectiveness results have been investigated via deterministic sensitivity analyses. Infliximab was priced according to the BNF listed price which has been unchanged since 2012–2013.A CUA is adopted to evaluate the cost-effectiveness of alternative treatments in ASUC patients, and to provide evidence for policy makers on reimbursement decisions, which uses Quality Adjusted Life Year (QALY) as a health outcome. CUA evaluates the cost-effectiveness of infliximab versus ciclosporin in terms of costs and QALY implications. An incremental cost-effectiveness ratio (ICER) is estimated (if an intervention appears to be more effective and more costly than a comparator) and compared with the UK National Institute for Health and Care Excellence (NICE) recommended willingness-to-pay threshold value, £20,000 per QALY gain. Following NICE recommendations a discounting rate of 3.5% per annum was applied to both costs and QALYs occurring beyond 12 months from two alternative treatments.