Quantitative measures of rheumatic diseases for clinical research versus standard clinical care: differences, advantages and limitations

No single measure can serve as a 'gold standard' for the diagnosis, prognosis, and monitoring of patients with rheumatic diseases. Therefore, pooled indices of several measures have been developed for patient assessment. Quantitative measures and indices in rheumatology have been used primarily in clinical trials and other clinical research, but not in standard clinical care. Indeed, most standard rheumatology care is conducted without quantitative data other than laboratory tests, which often are uninformative. Some measures used in research have been adapted for standard care. The classical 66/68-joint count with graded scoring for swelling, tenderness, pain on motion, limited motion, and deformity has been shortened for clinical care to a 28-joint count, scored only as 'Yes' or 'No' for swelling or tenderness. Patient questionnaires designed for clinical research can be lengthy, with complex scoring, so that information is not available to help guide clinical decisions. By contrast, patient questionnaires designed for standard care, such as a simple one-page, multi-dimensional health assessment questionnaire (MDHAQ), are short, save time, are easily scored, and are useful in all rheumatic diseases to monitor patient status at each visit and document changes over long periods. More attention to measures for use in standard care could improve care and outcomes for patients with rheumatic diseases.