Purpose: To critically appraise and summarize evidence on the cost-effectiveness of biologic DMARDs compared to conventional DMARDs for rheumatoid arthritis (RA) in adults in Canada. Method: Electronic search of Medline, Embase, National Health Services Economic Evaluation Database, HealthStar, Econlit and Tufts CEA Registry from inception to November 2008 for economic evaluations of biologics compared to conventional DMARDs. Selected studies were critically appraised using the British Medical Journal checklist (Drummond 1996). The Phillips (2004) checklist was also used for economic modeling studies. Extensive study heterogeneity prohibited quantitative synthesis; therefore results were stratified by patient and treatment characteristics. After converting currencies to 2009 Canadian (CDN) dollars and adjusting for inflation, non-parametric descriptive statistics were used to describe results, including incremental cost-effectiveness ratios (ICERs) (reported in CDN$ per quality-adjusted life-years [QALYs]). Result: Title and abstracts of 918 citations were screened, 58 studies were retrieved for full-text screen, and 19 economic evaluations (of which 2 were Canadian) were selected. Of these, 4 conducted cost-effectiveness and 17 conducted cost-utility analyses. Evaluated biologics included adalimumab and infliximab (as monotherapies or combined with methotrexate), and etanercept. Many studies did not adhere to standard guidelines for conducting economic evaluations. In DMARD-naïve RA patients modeled to receive a biologic therapy positioned within a DMARD sequence compared to a no-biologic DMARD sequence, ICERs ranged from 62,213 to 1,775,640 (median 130,358). In modeled RA patients resistant to ≥1-2 DMARDs, ICERS for the same comparison ranged from 34,654 to 1,006,150 (median=72,131). There is evidence to suggest that biologics prescribed to early RA patients result in more QALYs and lower ICER values than in late RA patients (QALY range: 0.92–1.57 versus 0.22–0.88, ICER range 75,001-90,846 versus 133,988-381,850, respectively). The median ICER value in cost-utility analyses of biologics used according to Canadian guidelines, from payer and societal perspectives, were 106,884 and 64,390, respectively. Conclusion: The evidence is difficult to synthesize due to enormous heterogeneity in study design. Despite substantial variation in estimates, biologics are clearly more expensive, but produce more QALYs, than conventional DMARDs. However, ICERs are substantially smaller in analyses that consider productivity (i.e., those conducted from the societal perspective) and in analyses that compared biologics in early versus later RA. Future analyses should explicitly examine the impact of biologics in assisting RA patients lead productive lives.
Candidate for the Lee B. Lusted Student Prize Competition