Cost-effectiveness of modified-release prednisone in the treatment of moderate to severe rheumatoid arthritis with morning stiffness based on directly elicited public preference values

Abstract

William Dunlop,1 Itrat Iqbal,1 Ifty Khan,2 Mario Ouwens,3 Louise Heron4 1Mundipharma International Limited, Cambridge, 2University College London, London, United Kingdom; 3Mapi HEOR, Houten, The Netherlands; 4Adelphi Values, Macclesfield, Cheshire, United Kingdom Background: Assessing the cost-effectiveness of treatments in rheumatoid arthritis (RA) is of growing importance due to the chronic nature of the disease, rising treatment costs, and budget-constrained health care systems. This analysis assesses the cost-effectiveness of modified-release (MR) prednisone compared with immediate-release (IR) prednisone for the treatment of morning stiffness due to RA. Methods: A health state transition model was used to categorize RA patients into four health states, defined by duration of morning stiffness. The model applied a 1-year time horizon and adopted a UK National Health Service (NHS) perspective. Health benefits were measured in quality-adjusted life years (QALYs) and the final output was the incremental cost-effectiveness ratio (ICER). Efficacy data were derived from the CAPRA-1 (Circadian Administration of Prednisone in Rheumatoid Arthritis) study, drug costs from the British National Formulary (BNF), and utility data from a direct elicitation time-trade-off (TTO) study in the general population. Sensitivity analyses were conducted. Results: Mean treatment costs per patient were higher for MR-prednisone (£649.70) than for IR-prednisone (£46.54) for the duration of the model. However, the model generated an incremental QALY of 0.044 in favor of MR-prednisone which resulted in an ICER of £13,577. Deterministic sensitivity analyses did not lead to significant changes in the ICER. Probabilistic sensitivity analysis reported that MR-prednisone had an 84% probability of being cost-effective at a willingness-to-pay threshold of £30,000 per QALY. The model only considers drug costs and there was a lack of comparative long-term data for IR-prednisone. Furthermore, utility benefits were not captured in the clinical setting. Conclusion: This analysis demonstrates that, based on the CAPRA-1 trial and directly elicited public preference values, MR-prednisone is a cost-effective treatment option when compared with IR-prednisone for RA patients with morning stiffness over one year, according to commonly applied UK thresholds (£20,000–£30,000 per QALY). Further research into the costs of morning stiffness in RA is required. Keywords: modified-release prednisone, rheumatoid arthritis, morning stiffness, cost-effectiveness analysis, cost utility analysis, quality of life