Modeling and cost-effectiveness analysis of etanercept in adults with rheumatoid arthritis in Japan: a preliminary analysis

• DOI: 10.1007/s10165-006-0461-y
• Publication Date: 2006-04-21T17:22:30Z
• Authors: Makoto Tanno; Ichiro Nakamura; Katsumi Ito; Hidekazu Tanaka; Hisahiko Ohta; Makoto Kobayashi; Akitoshi Tachihara; Masakazu Nagashima; Shinichi Yoshino; Atsuo Nakajima
• Keywords: Discontinuation; Combination therapy; Sulfasalazine; Antirheumatic drugs

The tumor necrosis factor (TNF) antagonist etanercept is an antirheumatic agent which was approved by Japanese regulatory authorities in January 2005. In Japan, the cost-effectiveness of this therapy for patients with rheumatoid arthritis (RA) has not previously been evaluated. This study models cost-utility comparison standard disease-modifying drugs (DMARDs) among adult RA who have failed a previous course DMARD bucillamine. A Markov model 6-month cycles constructed to compare two therapeutic strategies: versus therapy. For each cycle, one three options possible: patient could (i) remain on current if American College Rheumatology criteria 20% clinical improvement (ACR20) were achieved, (ii) switch another drug pathway ACR20 achieved or side effects severe enough cause treatment discontinuation occurred, (iii) they die. strategy etanercept, methotrexate (MTX), sulfasalazine (SSZ), combination (MTX + SSZ) and, finally, no DMARD. identical except initial MTX (etanercept excluded). Results from trials U.S. and European populations used derive probabilities disease progression, response therapy, relationships between functional as measured Health Assessment Questionnaire (HAQ) disability index. An equation developed predict utility HAQ scores patients. Costs medical services Japan obtained April 2003. Analysis conducted societal perspective, including lost productivity costs due premature mortality. discounted at 6% annually, quality-adjusted life years (QALYs) 1.5% annually. Model parameters varied above below base-case values sensitivity analyses. Compared ¥6.39 million more costly per but yielded additional 2.56 QALYs. incremental ratio ¥2.50 million/QALY. Sensitivity analyses revealed that most strongly influenced acquisition cost percentage recipients ACR20. Using commonly applied thresholds acceptable United States ($50000 = ¥5.5 million/QALY) Kingdom (£30000 ¥5.7 million/QALY), can be considered cost-effective. Cost-utility ratios did exceed these any analysis. Further should once epidemiologic data become available.