RT Journal Article
SR Electronic
T1 Validation of OMERACT preliminary rheumatoid arthritis flare domains in the NOR-DMARD study
JF Annals of the Rheumatic Diseases
JO Ann Rheum Dis
FD BMJ Publishing Group Ltd and European League Against Rheumatism
SP 1781
OP 1787
DO 10.1136/annrheumdis-2013-203496
VO 73
IS 10
A1 Elisabeth Lie
A1 Thasia G Woodworth
A1 Robin Christensen
A1 Tore K Kvien
A1 Vivien Bykerk
A1 Daniel E Furst
A1 Clifton O Bingham III
A1 Ernest H Choy
A1 the OMERACT RA Flare Working Group
YR 2014
UL http://ard.bmj.com/content/73/10/1781.abstract
AB Objective Domains identified as a result of qualitative research and Delphi exercises to assess rheumatoid arthritis (RA) flare include pain, function, swollen and tender joints, patient and physician global, laboratory measures, participation, stiffness, self-management and fatigue. Here we examine aspects of construct and content validity of these domains in a longitudinal observational study. Methods A total of 1195 patients with RA treated with non-biological disease-modifying antirheumatic drugs (DMARDs) or biologics were eligible for the analyses. Working definitions of ‘flare’ included patient-reported worsening between 3 and 6 months (primary) and treatment change at 6 months (DMARDs and/or systemic corticosteroids) (secondary). Available outcome measures were mapped to the flare domains. Changes between 3 and 6 months were compared between patients with and without ‘flare’. Convergent and divergent construct validity and content validity were assessed by correlation analyses and logistic regression analysis, respectively. Results Applying the flare working definition based on patient-reported worsening, standardised mean differences (SMDs) were >0.5 for the majority of outcomes. The largest SMDs were observed for Pain visual analogue scale (1.30), SF-36 Bodily pain (1.24), Patient global (1.20) and morning stiffness intensity (1.17). The flare working definition based on treatment change yielded lower SMDs (<0.5 for most variables). Consistently stronger intradomain than corresponding interdomain correlations supported convergent and divergent validity of the domains. Conclusions Probing a flare definition via outcome measures, the identified flare domains discriminated well between patients with and without worsening. Interdomain and intradomain correlation and logistic regression analyses provide further support for construct and content validity of the identified flare domains.