Rheumatoid Arthritis: Anis A

Bansback N, Marra CA, Finckh A, Anis A. · Centre for Health Evaluation and Outcome Sciences, St Paul's Hospital, BC, Canada. · Best Pract Res Clin Rheumatol. · Pubmed #19233048 No free full text.

Abstract: Recent years have witnessed a shift in the therapeutic approach for patients with early rheumatoid arthritis (RA). The focus of interest has been the improved outcomes achieved through the use of early aggressive disease-modifying therapy, including the use of biologic agents. Such strategies have acquisition costs which typically exceed those of older anti-rheumatic strategies. However, improved outcomes might lead to fewer hospitalizations and physician visits and improved employability, leading to future cost savings. This is in addition to the health benefits which patients value as improvements in quality of life. With many services competing to spend often limited health-care budgets, information on the relative benefits and costs of new approaches for treating RA can be useful in deciding on efficient allocation and treatment decisions.

Bansback N, Ara R, Karnon J, Anis A. · Centre for Health Evaluation and Outcome Sciences, St Paul's Hospital, Vancouver, British Columbia, Canada. · Pharmacoeconomics. · Pubmed #18429656 No free full text.

Abstract: We reviewed the clinical measures used in rheumatoid arthritis (RA) economic evaluations with respect to their relevance and sensitivity to changes in survival, health-related quality of life (HR-QOL) and costs. We compared the measures from the economic perspective and discussed the validity of methods used to extrapolate beyond the trial data. Cost-effectiveness evaluations of disease-modifying antirheumatic drugs in RA were identified by searching MEDLINE, EMBASE, Econlit and NHS EED databases. Studies were retained if they extrapolated beyond randomized controlled trial evidence using relationships between clinical measures, costs and utilities.In the 22 studies identified, clinical severity was measured using the Health Assessment Questionnaire (HAQ) Disability Index, the American College of Rheumatology (ACR) response criteria, the Disease Activity Score (DAS) or a combination of the HAQ and DAS. The HAQ is correlated with mortality, costs and HR-QOL instruments, and several studies used linear relationships to model these associations. However, a polynomial relationship or discrete states may be more appropriate for patients at the extremes of the disease spectrum, and numerous HAQ health states may be required to capture differences in mortality risk. While the ACR response criteria is a more comprehensive measure than the HAQ, it is a relative measure, which creates difficulties when estimating absolute changes in HR-QOL, costs and mortality risk. The evidence base linking DAS scores with HR-QOL instruments, costs and mortality is less robust, possibly due to the comparatively recent development of the measure and the limited number of possible scores (mild/moderate/severe). While there is some evidence of a relationship between DAS scores and costs, the DAS does not capture all aspects of HR-QOL, and no significant relationship has been established with mortality risk.Evidence suggests the HAQ to be the primary clinical measure for use in economic evaluations as it is measured in almost all clinical studies, and is closely correlated to health utilities, mortality and costs. While new developments suggest the sensitivity of health states may be improved by combining the HAQ with measures such as the DAS, further research is required in this area. Further research is also required to explore the advantages in using either continuous or discrete health states.

Bansback N, Ara R, Ward S, Anis A, Choi HK. · Centre for Health Evaluation and Outcome Sciences, St Paul's Hospital, Vancouver, British Columbia, Canada. · Pharmacoeconomics. · Pubmed #19178122 No free full text.

Abstract: HMG-CoA reductase inhibitors (statins) are potentially excellent candidate agents for patients with rheumatoid arthritis (RA). They reduce both cardiovascular risks and RA disease activity. To evaluate the potential long-term effects of statin therapy among patients with RA, and to determine their associated cost effectiveness by incorporating both the cardiovascular and the anti-rheumatic benefits. A Markov decision-analytic model was developed to simulate cardiovascular and RA disease profiles over time. The impact of statin therapy was estimated by adjusting the risk of coronary heart disease (CHD) events and changes in the RA Disease Activity Score (DAS28), based on the results of a randomized trial. The benefits (QALYs) and costs (in year 2005 values) were evaluated from a US payer perspective. A full uncertainty analysis, including a value-of-information (VOI) analysis, was undertaken to evaluate the importance of individual parameters. Using a 10-year time horizon, the additional cost and QALYs of statin therapy were estimated to be USD4690 and 0.44 QALYs, respectively, resulting in an incremental cost-effectiveness ratio (ICER) of USD10 650 per QALY (95% CI 1525, 156 565). The QALY gain associated with statin therapy depended more on the anti-rheumatic effects of statin therapy than on its cardiovascular prevention effect. The VOI analysis found the long-term benefit of statin therapy (i.e. >or=12 months) and the consequent impact on quality of life to be the most uncertain and, therefore, influential parameters. Our analysis indicates that the dual anti-inflammatory/cardiovascular benefits of statins could make this therapy highly cost effective in RA. However, uncertainties remain in the available data, warranting further research on refining the precise RA disease-activity benefits and health-utility changes associated with statin therapy, at least over a 12-month period.

Bansback N, Marra C, Tsuchiya A, Anis A, Guh D, Hammond T, Brazier J. · St. Paul's Hospital, Vancouver, British Columbia, Canada. · Arthritis Rheum. · Pubmed #17665482 links to  free full text

Abstract: OBJECTIVE: To estimate the relationship between preference-based measures, EuroQol (EQ-5D) and SF-6D, and the Health Assessment Questionnaire (HAQ) disability index (DI) in patients with rheumatoid arthritis (RA), and to characterize components that are predictors of health utility. METHODS: Patients with RA participating in 2 studies in the UK (n = 151) and Canada (n = 319) completed the HAQ, EQ-5D, and Short Form 36 (SF-36). The SF-36, a generic measure of quality of life, was converted into the preference-based SF-6D. From these results we developed models of the relationship between the HAQ and SF-6D and EQ-5D using various regression analyses. RESULTS: The optimal model developed for the EQ-5D entered levels for each item as independent variables (model 5). A root mean square error (RMSE) of 0.18 suggested relatively good predictive ability. For the SF-6D, RMSEs were lower (0.09), suggesting better predictions than for the EQ-5D, but models with more explanatory variables did not improve results (model 2 or 4 optimal). The models were able to predict actual SF-6D and EQ-5D across the range of the HAQ DI. CONCLUSION: Our approach enabled calculations of quality-adjusted life years from existing trials where only the HAQ was measured. All aspects of the HAQ may not be reflected in the preference-based measures, and this method is suboptimal to direct measurement of health state utility in clinical trials. Given this limitation, our approach provides an alternative for researchers who need health-state utility values, but had not included a preference-based measure in their clinical study because of resource constraints or a desire to limit patient burden.

Bansback N, Maetzel A, Drummond M, Anis A, Marra C, Conway P, Boers M, Tugwell P, Boonen A. · Centre for Health Evaluation and Outcome Sciences, St. Paul's Hospital, Vancouver, British Columbia, Canada. · J Rheumatol. · Pubmed #17477483 No free full text.

Abstract: Since healthcare resources are scarce, choices have to be made on how they will be allocated. The use of economic evaluations using cost-effectiveness analyses has increased rapidly as policymakers have realized their value in maximizing the population's benefits (in terms of length of life and health status) within a given budget. Following efforts by OMERACT to create reference case definitions for the conduct of economic evaluation in rheumatoid arthritis, osteoporosis, and osteoarthritis, we review various methodological areas and research decisions that could benefit from a consensus between researchers, clinicians, and drug developers in terms of an ankylosing spondylitis (AS) reference case. Ten methodological issues are presented that will be important for future development of evaluations. Tentative proposals to define the issues in a reference case for AS are made, along with recommendations for further research.