CLICK HERE TO VIEW THE CORRECTED VERSION OF THIS ARTICLERheumatoid arthritis (RA) is a chronic autoimmune disease that is associated with inflammation of the articular synovium in joints, resulting in bony erosions, deformity, and ultimately joint destruction. It is also a polysystemic disease affecting the lungs, heart, kidneys, nerves, and muscles, and is often associated with generalized fatigue, poor sleep, and decreased energy. It is not surprising then that patients with RA generally have poor health-related quality of life (HRQOL).1 A vast array of instruments has been created to measure HRQOL. They are typically divided into 2 categories— generic and disease-specific. Generic measurements include health profiles and instruments that generate health utilities, whereas disease-specific instruments include activities of daily living and function specific to the disease in question. These approaches are not mutually exclusive, and each approach has its strengths and weaknesses. With the increasing availability of measurements used in HRQOL evaluations, criteria are needed for selecting appropriate instruments for RA patients.
In this supplement, we aim to review how HRQOL instruments are utilized and how they help to individually assess quality of life (QOL). These instruments are intended as a means to better understand which therapies provide meaningful relief to patients in addition to supplying the rigorous assessments necessary to evaluate a drug’s efficacy in a given clinical setting. It is important that clinical trials using these instruments are assessed not only by reviewing traditional end points, but also by taking into account data that provide insight into the effectiveness of individual therapies in improving patients’ well-being.
The first article, by Drs Khanna and Tsevat, provides an overview of HRQOL and a comprehensive description on the attributes of different instruments to measure it. Different applications of the instruments are also analyzed, including their utility to estimate burden of disease, as end points in clinical trials, to monitor outcomes in clinical practice, and their uses in public policy and individual decision making. The Medical Outcomes Study 36-Item Short Form (SF-36) and the Health Assessment Questionnaire Disability Index (HAQ-DI) are perhaps the most well-known and widely used generic and disease-specific health status measures in the evaluation of RA patients, respectively.
The second article analyzes the performance of the SF-36 against criteria proposed by an international network that aims to improve Outcome Measurement in Rheumatology Clinical Trials (OMERACT). In light of these criteria, Drs Tugwell and Wells and Ms Idzerda analyzed data from 7 placebo- controlled trials and found evidence that the SF-36 deserves serious consideration for inclusion in the core set of outcomes in RA trials.
A recent major advance in the field of rheumatology is the introduction of biologic disease-modifying antirheumatic drugs (DMARDs) for the treatment of patients with moderate-to-severe RA. Some of these drugs not only induce symptomatic remission but also improve HRQOL. Pivotal clinical trials with combinations of biologics and other DMARDs have reported significant improvement in HRQOL (eg, fatigue, functionality, and mental health). Survival per se is no longer the only treatment goal for RA. Another goal is to improve, restore, or preserve HRQOL. Results from these clinical trials are analyzed by Drs Strand and Singh in the third article in this supplement.
QOL measurement has a rich history in rheumatology, and although the study of health measurements has expanded remarkably in recent years, there are a number of methodologic issues that remain unresolved, including the role of duration, prognosis in health outcome assessment, the measurement of quality, the utility assessment method, and the use of SF-36 or HAQ-DI for cost-utility studies. Dr Kaplan discusses these crucial issues and identifies important directions for future research.
1. Mili F, Helmick CG, Moriarty DG. Health related quality of life among adults reporting arthritis: analysis of data from the Behavioral Risk Factor Surveillance System, US, 1996-99. J Rheumatol. 2003;30:160-166.