Abstract
OBJECTIVE: Stiffness was endorsed within the rheumatoid arthritis (RA) flare core domain set at the previous Outcome Measures in Rheumatology meeting (OMERACT 11). Two stiffness breakout groups at the present OMERACT 12 RA flare workshop discussed results of new qualitative studies in RA stiffness. METHODS: Results from 2 independent studies of RA stiffness were presented to breakout group participants, followed by group discussions about stiffness measurement. RESULTS: Both studies identified stiffness as complex, variable with the level of disease activity, and as encompassing concepts of impact, intensity, timing, location, and duration. That stiffness has an effect on multiple dimensions of health was a common finding. Participants agreed that stiffness is an important aspect of RA flare. Whether measuring only morning stiffness duration, the traditional approach in RA, was sufficient in coverage of the concept was unclear. Groups agreed that more research on stiffness measurement is needed considering the importance patients place on the effect of stiffness. CONCLUSION: Results from independent studies highlight stiffness effect as an important feature of RA, in addition to intensity, timing, location, and duration. Additional work is needed to identify optimal ways to assess stiffness in RA and other rheumatologic diseases.