Identifying flares in rheumatoid arthritis: reliability and construct validation of the OMERACT RA Flare Core Domain Set

Abstract

ObjectiveTo evaluate the reliability of concurrent flare identification using 3 methods (patient, rheumatologist and Disease Activity Score (DAS)28 criteria), and construct validity of candidate items representing the Outcome Measures in Rheumatology Clinical Trials (OMERACT) RA Flare Core Domain Set.MethodsCandidate flare questions and legacy measures were administered at consecutive visits to Canadian Early Arthritis Cohort (CATCH) patients between November 2011 and November 2014. The American College of Rheumatology (ACR) core set indicators were recorded. Concordance to identify flares was assessed using the agreement coefficient. Construct validity of flare questions was examined: convergent (Spearman's r); discriminant (mean differences between flaring/non-flaring patients); and consequential (proportions with prior treatment reductions and intended therapeutic change postflare).ResultsThe 849 patients were 75% female, 81% white, 42% were in remission/low disease activity (R/LDA), and 16–32% were flaring at the second visit. Agreement of flare status was low–strong (κ's 0.17–0.88) and inversely related to RA disease activity level. Flare domains correlated highly (r's≥0.70) with each other, patient global (r's≥0.66) and corresponding measures (r's 0.49–0.92); and moderately highly with MD and patient-reported joint counts (r's 0.29–0.62). When MD/patients agreed the patient was flaring, mean flare domain between-group differences were 2.1–3.0; 36% had treatment reductions prior to flare, with escalation planned in 61%.ConclusionsFlares are common in rheumatoid arthritis (RA) and are often preceded by treatment reductions. Patient/MD/DAS agreement of flare status is highest in patients worsening from R/LDA. OMERACT RA flare questions can discriminate between patients with/without flare and have strong evidence of construct and consequential validity. Ongoing work will identify optimal scoring and cut points to identify RA flares.

Rheumatoid Arthritis Morning Stiffness Is Associated With Synovial Fibrin and Neutrophils

“…If yes, how long did the stiffness last?” and the answer options “no stiffness,” “<30 minutes,” “30–60 minutes,” “1–2 hours,” “2–3 hours,” “3–4 hours,” “>4 hours,” and “all day,” were used to measure stiffness duration. The Outcome Measures in Rheumatology RA Flare Questionnaire , which includes the question “How severe was your stiffness over the past week?” with a 10‐point numerical rating scale to respond between no stiffness and severe stiffness, was used to measure stiffness severity.…”

Detection of Flares by Decrease in Physical Activity, Collected Using Wearable Activity Trackers in Rheumatoid Arthritis or Axial Spondyloarthritis: An Application of Machine Learning Analyses in Rheumatology

“…The evolution of rheumatoid arthritis (RA) and axial spondyloarthritis (SpA) is marked by alternated periods of flares and stable disease activity . Flares are important for patients because they contribute to the unpredictability of the disease .…”

“…Furthermore, due to the link between inflammation and structural degradation, flares are important in order to assess for disease management . There is growing interest in both RA and axial SpA to characterize the reality behind the concept of patient‐reported flares . Flares appear to have objective consequences on daily life and in particular on physical activity .…”

Incorporating the patient's perspective in outcomes research

“…Patients’ ratings of pain, fatigue, stiffness, function, and participation were shown to have strong evidence of content and consequential validity. Additional research will be directed at developing a scoring system to grade the severity of flares [22 ■ , 23 ■ ]. …”