Cost-effectiveness of TNF inhibitors vs synthetic disease-modifying antirheumatic drugs in patients with rheumatoid arthritis: a Markov model study based on two longitudinal observational studies

Rheumatology (Oxford). 2015 Jul;54(7):1226-35. doi: 10.1093/rheumatology/keu460. Epub 2015 Jan 7.

Abstract

Objective: The objective of this study was to estimate the additional costs and health benefits of adding a TNF inhibitor (TNFi) (adalimumab, certolizumab, etanercept, golimumab, infliximab) to a synthetic DMARD (sDMARD), e.g. MTX, in patients with RA.

Methods: We developed the Norwegian RA model as a Markov model simulating 10 years of treatment with either TNFi plus sDMARDs (TNFi strategy) or sDMARDs alone (synthetic strategy). Patients in both strategies started in one of seven health states, based on the Short Form-6 Dimensions (SF-6D). The patients could move to better or worse health states according to transition probabilities. In the TNFi strategy, patients could stay on TNFi (including switch of TNFi), or switch to non-TNFi-biologics (abatacept, rituximab, tocilizumab), sDMARDs or no DMARD. In the synthetic strategy, patients remained on sDMARDs. Data from two observational studies were used for the assessment of resource use and utilities in the health states. Health benefits were evaluated using the EuroQol-5 Dimensions (EQ-5D) and SF-6D.

Results: The Norwegian RA model predicted that 10-year discounted health care costs totalled €124,942 (€475,266 including production losses) for the TNFi strategy and €65,584 (€436,517) for the synthetic strategy. The cost per additionally gained quality-adjusted life-year of adding a TNFi was €92,557 (€60,227 including production losses) using SF-6D and €61,285 (€39,841) using EQ-5D. Including health care costs only, the probability that TNFi treatment was cost-effective was 90% when using EQ-5D, assuming a Norwegian willingness-to-pay level of €67,300.

Conclusion: TNFi treatment for RA is cost-effective when accounting for production losses. Excluding production losses, TNFi treatment is cost-effective using EQ-5D, but not SF-6D.

Keywords: Markov chain; antirheumatic agent; arthritis; cost-effectiveness; receptors; rheumatoid; tumour necrosis factor; type I.

Publication types

  • Observational Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adalimumab
  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Antibodies, Monoclonal / economics
  • Antibodies, Monoclonal / therapeutic use
  • Antibodies, Monoclonal, Humanized / economics
  • Antibodies, Monoclonal, Humanized / therapeutic use
  • Antirheumatic Agents / economics*
  • Antirheumatic Agents / therapeutic use*
  • Arthritis, Rheumatoid / drug therapy*
  • Biological Products / economics*
  • Biological Products / therapeutic use*
  • Cost-Benefit Analysis / statistics & numerical data*
  • Etanercept
  • Female
  • Health Status
  • Humans
  • Immunoglobulin G / economics
  • Immunoglobulin G / therapeutic use
  • Infliximab
  • Longitudinal Studies
  • Male
  • Markov Chains*
  • Methotrexate / economics
  • Methotrexate / therapeutic use
  • Middle Aged
  • Models, Statistical
  • Norway
  • Quality-Adjusted Life Years
  • Receptors, Tumor Necrosis Factor / therapeutic use
  • Treatment Outcome
  • Tumor Necrosis Factor-alpha / antagonists & inhibitors*
  • Young Adult

Substances

  • Antibodies, Monoclonal
  • Antibodies, Monoclonal, Humanized
  • Antirheumatic Agents
  • Biological Products
  • Immunoglobulin G
  • Receptors, Tumor Necrosis Factor
  • Tumor Necrosis Factor-alpha
  • Infliximab
  • Adalimumab
  • Etanercept
  • Methotrexate