The future of outcomes measurement in rheumatology

Quality-of-life (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 methodological issues that need attention. This article focuses on utility-based measures that are most relevant to public policy and some major issues that remain unresolved. The duration of a health condition, for example, is a central component of health outcome. However, the majority of measures currently used in rheumatology do not consider the duration of condition or the long-term consequences of disease or treatment. Similarly, there are many levels at which preference is expressed in the healthcare decision process, and despite a wealth of literature on QOL measurement, we still have much more to learn about how to present information to patients and how to use preference data that patients provide. Improvements in the utility assessment method are urgently needed as well, as different utility-based measures such as standard gamble, time trade-off, and rating scales are not comparable. This lack of comparability has important implications when estimating quality-adjusted life-years in cost-utility studies. Another key unresolved issue is whether the Medical Outcomes Study 36-Item Short Form and the Health Assessment Questionnaire offer appropriate data for cost-utility studies. The current estimation of clinical benefit is also controversial, as competing measurement tools offer different estimates of wellness at baseline. However, the different approaches yield surprisingly similar estimates of change. Clearly, this observation deserves further study and replication in future studies.