The RADAI joint index designed for rheumatoid arthritis patients provides equally powerful information about disease status in osteoarthritis and psoriatic arthritis, according to a new comparative study. As a guide to severity, it is much quicker than waiting for lab results to come in.
Castrejn I, Yazici Y, and T Pincus. Patient self-report RADAI (Rheumatoid Arthritis Disease Activity Index) joint counts on an MDHAQ (Multidimensional Health Assessment Questionnaire) in usual care of consecutive patients with rheumatic diseases other than rheumatoid arthritis. Arthritis Care Res (2013) 65: 288–293. doi: 10.1002/acr.21793
Although it has RA in its name, the self-reported Rheumatoid Arthritis Disease Activity Index (RADAI) of joint involvement and pain also provides valuable information about other rheumatic diseases, long before the lab test results come in. This insight comes from the first study by rheumatologist Theodore Pincus MD and his team at the NYU Hospital for Joint Diseases judging how these simple patient surveys hold up as quick initial measures of severity for osteoarthritis (OA), lupus (SLE), psoriatic arthritis (PSa) and gout.
Previous studies have used the RADAI only for RA and, in one trial, for ankylosing spondylitis.
The current study analyzed records from 465 consecutive patients (drawn from a prospective database of more than 1,500), two-thirds of whom were women, the majority Caucasian. Subjects were waiting to see a rheumatologist at a single center as part of their routine care for a rheumatologic condition. They also completed the Multidimensional Health Assessment Questionnaire (MDHAQ) scales.
The RADAI scores proved to add information beyond MDHAQ. Sixty-four percent of RA patients reported involvement in four or more of their own joint groups, as did nearly as many patients with OA (58%) and PSa (57%). The number of joints reported was not significantly different for these three conditions. SLE and gout were significantly different: Only a third of patients with SLE and 18% of those with gout reported four or more involved joint groups, and the number of joints was significantly smaller.
Often the only qualitative data a rheumatology patient’s medical records are the lab results, which usually aren’t available until after a particular visit, note these researchers. RADAI reports “may actually be preferable,” they contend, offering valuable information for discussion and action with minimal effort on the rheumatologist’s part.