Evaluating severity and status in rheumatoid arthritis

Abstract

There is general agreement regarding the most appropriate examinations and methods to use to evaluate change in status in randomized controlled trials (RCT). However, no guidelines exist to aid in determining and evaluating actual status rather than change in status, particularly when applied to individual patients with rheumatoid arthritis (RA). In addition, methods appropriate for clinical trials may not be useful in evaluating individual patients because of time constraints. This report reviews current methods of evaluation and develops modified methods, based on data bank research that will be useful in clinical practice and in the evaluation of RCT and observational studies. Using data from longitudinal observational data banks, further reduction in the number of joints examined is evaluated to reconcile the time constraints of clinical practice with the need to maintain reliability and validity. Percentile methods to determine severity status are applied to the variables used in RCT and extended further to observational studies and routine clinical practice. Shortened joint counts, based on modifications of the Ritchie method, are identified that allow for examination of groups of 18 (clinical-18) and 16 (clinical-16) joints, the clinical-16 omitting the metatarsophalangeal joints. Using percentile charts, actual severity valuations are given to the variables evaluated in the clinic as well as in RCT. Disease activity status of clinic patients can be determined quantitatively thus allowing clinicians further insight into the status and prognosis of their patients. By quantifying disease activity severity, clinicians and 3rd party payers can better evaluate the appropriateness of and response to disease modifying antirheumatic drugs and biologic therapies. Further, RCT can be evaluated as to severity status of patients participating, and the generalizability of RCT can be better evaluated.