Quality of life measures: use and abuse

Health status and quality of life measures are widely used in the clinical assessment of rheumatoid and other forms of arthritis. A range of measures is available, mainly as self-administered instruments. Most of these are reliable, valid and sensitive to change. They can be used to assess clinical status, evaluate effectiveness in randomized trials, define outcome and help to plan for health-care needs for people with arthritis. The instruments form a continuum with assessments of disease activity and functional disability. Some instruments are specifically designed for use in rheumatoid arthritis, other instruments are generic and can be used across a range of conditions including arthritis, and some generic instruments can be specifically scored to reflect the problems most prominent in arthritis. There are trade-offs between simplicity and sensitivity and between using familiar and unusual instruments. Against this background, the most widely used disease-specific measure remains the health assessment questionnaire (HAQ), and the most commonly employed generic measure is the SF-36. Evidence currently suggests focusing on these well-known and widely used measures. In both cases, the pain score is the predominant clinical assessment associated with poor health status measured using either instrument. HAQ scores also reflect unchanging aspects of patients' overall status, such as their degree of deprivation. It is sensible for all future clinical trials to include one disease-specific and one generic measure of health status.