Clinical Edge

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RA Disease Activity and PROMIS Measures

In measurement of patient-reported outcomes of rheumatoid arthritis (RA) disease activity, excellent agreement between the observed RAPID3 and predicted RAPID3 scores was estimated using several PROMIS (Patient-Reported Outcomes Measurement Information System) instruments, a new study found. Four PROMIS computer adaptive testing (CAT) instruments and RAPID3, along with pain intensity and patient global assessment score, were administered to participants in the ArthritisPower registry. The RAPID3 was predicted using different combinations of variables to create a new score. Among the findings:

  • 6,154 eligible patients (mean age 52.7 years, 93% women) contributed 11,275 observations.
  • The median assessment times ranged from 29 seconds to 116 seconds.
  • As single pairwise comparisons, the PROMIS CATs examined were modestly correlated to one another and RAPID3.
  • Along with the pain intensity and patient global, the PROMIS instruments explained a high fraction of total variance or the RAPID3 score.


Yun H, Nowell WB, Curtis D, et al. Assessing RA disease activity with PROMIS measures using digital technology. [Published online ahead of print March 30, 2019]. Arthritis Care Res (Hoboken). doi:10.1002/acr.23888.


Disease activity in RA is routinely measured using several objective scores including RAPID3. In this study, the authors used several patient-reported outcomes and studied their agreement with RAPID3 in a patient registry of all rheumatic diseases using a calculated “CAT PROMIS RAPID3” score. Both diagnosis and PRO’s were self-reported, and patients were selected based on whether they had completed all 4 selected PROMIS instruments. The authors report a high correlation between the calculated predicted RAPID3 and the collected RAPID3, as well as a reduced period of time required of patients to fill out the PRO instruments. This is a promising finding, though possibly not generalizable given the special features of this registry: the registry originated via an online support community (Creaky Joints) and UAB; patients were 90% white, 93% women, and possibly more technologically savvy and motivated than a general rheumatic disease population. The original RAPID3 scores also placed most patients in a high disease activity state, suggesting some skewing. In addition, the calculated RAPID3 does require time on the part of the recorder to apply the scale and calculate the score. Still, the study shows the potential of PRO use in capturing patient disease activity information between and before visits. —Arundathi Jayatilleke, MD