Modelling the cost-effectiveness of etanercept in adults with rheumatoid arthritis in the UK.

OBJECTIVES: This model examines the cost-effectiveness of etanercept monotherapy under British Society for Rheumatology guidelines, i.e. adults previously failing two disease-modifying anti-rheumatic drugs (DMARDs). It compares a DMARD sequence with etanercept third line against the same sequence excluding etanercept.

METHOD: The 6-monthly trend in Health Assessment Questionnaire (HAQ) disability score is simulated for 10 000 patients' lifetimes using clinical trial data and published literature. Switching to the next treatment is triggered by lack of response, loss of efficacy or adverse events. Patient mortality depends on rheumatoid arthritis life-tables and on epidemiological evidence relating reduced risk to HAQ improvement. Regression of HAQ/EuroQol (EQ-5D) utility provides quality-adjusted life years (QALY) gained. Primary analysis includes drug costs, monitoring and hospitalizations.

RESULTS: The central estimate cost per QALY is pound 16 330. Sensitivity analyses ( pound 7800 to pound 42 000) showed long-term HAQ progression (etanercept, DMARDs, non-responders) as most sensitive variables. The inclusion of potential avoided nursing home admissions and indirect costs/lost employment further improves the cost-effectiveness.

CONCLUSIONS: For adults in the UK, the results suggest that etanercept is cost-effective when compared with non-biologic agents. The National Institute for Clinical Excellence has accepted that etanercept is cost-effective and recommended its availability for use in patients who have failed at least two DMARDs. This model was an important component of that decision. The model is further suitable for use for a wide range of other cost-effectiveness questions in rheumatoid arthritis.