Complex measures and indices for clinical research compared with simple patient questionnaires to assess function, pain, and global estimates as rheumatology "vital signs" for usual clinical care.

Indices of multiple measures have been developed to assess and monitor patients with rheumatic diseases, as no single "gold standard" measure is available for diagnosis, prognosis, and monitoring of all individual patients. Rheumatology indices generally include 4 types of measures from a standard medical evaluation: patient history, physical examination, laboratory tests, and imaging studies. Well-characterized indices are available for rheumatoid arthritis (RA), psoriatic arthritis, systemic lupus erythematosus (SLE), ankylosing spondylitis, vasculitis, osteoarthritis, fibromyalgia, and other rheumatic diseases. These indices are complex and applied widely in clinical research, but rarely are scored in usual rheumatology patient encounters, which generally are conducted without quantitative data other than laboratory tests. Information from a patient often is as prominent in clinical decisions as information from a physical examination or laboratory tests, and is easily collected as standardized "scientific" data on patient questionnaires designed for usual clinical care, which require minimal professional effort. Patient-derived data-along with physical examination, laboratory, and imaging data-are useful rheumatology "vital signs" to assess and monitor patient status, provide documentation, and improve the quality of clinical care, in addition to their possible value for clinical research. Differences between complex measures for research and simple questionnaires designed for usual clinical care might be more widely recognized, to promote quantitative measurement in the infrastructure of usual rheumatology care.