PSYCHOLOGICAL MEASURES - PRACTICAL ISSUES IN OBSERVATIONAL STUDIES AND CLINICAL MONITORING

Psychological measures are important because they can influence the ex pression of pain and physical function in patients with arthritis. A n umber of instruments are now available that measure psychological dist ress and how we as individuals manage stress. These instruments have u ndergone extensive validation, although more work is required to evalu ate the performance of these instruments measuring change over time. O ne way to interpret psychological measures and to evaluate how they ch ange over time is to use normative comparisons Chat are conditional on rime and other relevant covariates, using statistical methods such as quantile regression. Such methods have been used to interpret the dev elopmental, educational, and physical growth of children. We can use s imilar methods to interpret observational studies and to guide decisio ns within the context of clinical practice.