Cost-utility of COBRA-light versus COBRA therapy in patients with early rheumatoid arthritis: The COBRA-light trial

Marieke M. Ter Wee*, Veerle M.H. Coupé, Debby Den Uyl, Birgit S. Blomjous, Esmee Kooijmans, Pit J.S.M. Kerstens, Mike T. Nurmohamed, DIrkjan Van Schaardenburg, Alexandre E. Voskuyl, Maarten Boers, Willem F. Lems

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review


Objective To evaluate if COmbinatie therapie Bij Reumatoïde Artritis (COBRA)-light therapy is cost-effective in treating patients with early rheumatoid arthritis (RA) compared with COBRA therapy. Methods This economic evaluation was performed next to the open-label, randomised non-inferiority COBRA-light trial in 164 patients with early RA. Non-responders to COBRA or COBRA-light received etanercept (50 mg/week) for 3-6 months. The societal perspective analysis took medical direct, non-medical direct and indirect costs into account. Costs were measured with patient cost diaries for the follow-up period of 52 weeks. Bootstrapping techniques estimated uncertainty around the cost-effectiveness ratios, presented in cost-effectiveness planes. Results 164 patients were randomised to either COBRA or COBRA-light strategy. At week 52, COBRA-light proved to be non-inferior to COBRA therapy on all clinical outcome measures. The results of the base-case cost-utility analysis (intention-to-treat analyses) revealed that COBRA-light strategy is more expensive (k9.3 (SD 0.9) compared with COBRA (k7.2 (SD 0.8)), but the difference in costs were not significant (k2.0; 95% CI-0.3 to 4.4). Also, both strategies produced similar quality-adjusted life-years (QALYs). The sensitivity analyses showed robustness of these results. In a per-protocol sensitivity analysis, in which costs of etanercept were assumed to be provided as prescribed according to protocol, both arms had much higher costs: COBRA-light: K11.5 (8.3) compared with k8.5 (6.8) for COBRA, and the difference in costs was significant (k2.9; 0.6 to 5.3). Conclusions In the base-case cost-utility analysis, the two strategies produced similar QALYs for similar costs. But it is anticipated that if protocol had been followed correctly, the COBRA-light strategy would have been more costly due to additional etanercept costs, for a limited health gain. Given the limited added benefit and high costs of starting etanercept in the presence of low disease activity in our trial, such a strategy needs better justification than is available now. Trial registration number 55552928, Results.

Original languageEnglish
Article numbere000502
JournalRMD Open
Issue number2
Publication statusPublished - 1 Oct 2017

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