Biologics for early rheumatoid arthritis: Review of health economic studies
Systematic review
|Updated
The Norwegian Knowledge Centre for the Health Services has reviewed the literature on the cost-effectiveness of biologic treatment for early RA as part of a project commissioned by the commissioned by the Norwegian Rheumatism Association.
Key message
It is estimated that 20 000-30 000 people in Norway suffer from the disease. Due to the patients’ reduced functional capacity, costs are incurred by employers, relatives and not least the patients themselves. Research has shown that early treatment with biologic drugs may be beneficial. Biologics are however more costly than conventional DMARDs, and Norwegian guidelines therefore stipulate that at least one DMARD should be attempted before treatment with biologic drugs is initiated. The Norwegian Knowledge Centre for the Health Services has reviewed the literature on the cost-effectiveness of biologic treatment for early RA as part of a project commissioned by the commissioned by the Norwegian Rheumatism Association.
Kunnskapssenteret har derfor på oppdrag fra Norsk Revmatikerforbund oppsummert helseøkonomiske studier som sammenligner kostnader og effekter av disse behandlingene.
We searched systematically for health economic evaluations of biologic treatment of patients with early RA (disease duration of three years or less) compared with DMARD treatment. We found six studies, which all incorporated a TNF-inhibitor such as aldalimumab, etanercept or infliximab. No studies on the other biologic drugs were found.
Our findings were:
- Treatment with biologic drugs in early RA may be cost-effective, though not necessarily as first-line treatment.
- This is consistent with current Norwegian guidelines which state that treatment with at least one DMARD should be attempted before biologic treatment is initiated.
- Inclusion of indirect costs has a major bearing on the results.
- The study results vary significantly.
Summary
Background
This report covers the cost-effectiveness associated with the use of biologic drugs in the treatment of early rheumatoid arthritis (RA) and forms the second part of a project commissioned by the Norwegian Rheumatism Association. The first part of the project consisted of a review of studies of efficacy and safety of biologic drugs for early RA and has been published in a separate report.
RA is a chronic autoimmune disease which affects the joints in the body which are covered by synovial fluid. International studies suggest that the prevalence is between 0.5% and 1% of the adult population. It is estimated that 20 000-30 000 people in Norway suffer from the disease. Due to the patients’ reduced functional capacity, costs are incurred by employers, relatives and not least the patients themselves.
Drug treatment of RA involves, inter alia , the use of disease-modifying anti-rheumatic drugs (DMARDs). It has been shown that early introduction of DMARDs provides greater health benefits and fewer adverse events compared to deferred DMARD treatment. Biologic drugs are more costly than conventional DMARDs, and Norwegian guidelines therefore stipulate that at least one DMARD should be attempted before treatment with biologic drugs is initiated.
Methods
We searched systematically for literature in EMBASE, Medline (Ovid) and Cochrane Library on September 15, 2009 and updated the search on March 10, 2010. In addition, we went through the reference lists of relevant publications, searched for relevant websites and contacted experts, affected companies and the Norwegian Rheumatism Association.
Results
Six studies were included; one of the cost-effectiveness type and the remainder of the cost—utility variety. The studies were from the period 2002-2009. The included studies were critically appraised using The Norwegian Knowledge Centre for the Health Services’ checklist for health economic evaluations. .
Bearing in mind the studies’ limited transferability with respect to the Norwegian context, it seems that strategies which incorporate biologic drugs generate more QALYs than strategies which only involve treatment with conventional DMARDs. Strategies which include biologic drugs against early RA can be cost-effective but not necessarily when biologics are used as first-line treatment.
Discussion
Of the six studies included, four were from the US, one from the UK and one from the Netherlands. It is hard to draw general conclusions on the basis of these studies. The transferability to the Norwegian context is limited, not least with respect to the US studies due to notable differences in the price and cost structure between the two countries’ health sectors. The variation in study results may, besides differences in costs and discount rates, also be ascribed to differences in the compared sequences and the construction of the models. Variation may also be a result of disparities in the calculated links between HAQ, mortality and the quality of life measures such as SF-6D, HUI and EQ-5D.
Whether or not indirect costs are included in the calculations has a significant bearing on the results. The pivotal question is thus: Will early biologic treatment of RA will contribute to work retention and prevent premature departure from working life is thus pivotal.
The results of studies which have investigated the association between the use of biologic drugs and work capability have not been unambiguous, although recent studies suggest a positive effect. The inclusion of indirect costs is however not the only important factor, but also the method in which they are measured . Costs calculated based on the assumption of a permanent loss of productive capacity (human capital method) will be much higher than those based on the assumption that the manpower lost may be quickly replaced (friction cost method).
Conclusion
We found six economic evaluations of biologic treatment of early RA. The studies included the TNF-antagonists adalimumab, etanercept and infliximab. No studies on the other biologic drugs were found. The results vary significantly, but it seems that the three drugs previously mentioned may nevertheless be cost-effective in the treatment of early RA, though not as first line treatment. We recommend that a health economic model be developed, based on Norwegian epidemiological, work participation and cost data, in order to assess the effectiveness of biologics in early RA in this country.