Patient-perceived flares in rheumatoid arthritis: A sub-analysis of the STRASS treatment tapering strategy trial

Abstract

Objectives: Patient's and physician's perspective can differ in rheumatoid arthritis (RA). The aim was to define the concept of patient-reported flares.

Methods: Post-hoc analysis of a randomized controlled trial of a step-down strategy in RA patients treated with anti-TNF, in DAS28-remission for ≥6 months, randomized to either "spacing" or "maintaining" anti-TNF. The occurrence of patient-reported flares (PRF) was evaluated every 3 months for 18 months by: "Over the last 3 months, did you experience symptoms suggestive of disease exacerbation?". Visits with and without PRF were compared, using a linear mixed effects model, in terms of symptoms, disability based on the Health Assessment Questionnaire, quality of life based on Short Form 36 Health Survey and DAS28-based relapses (DBR), defined as an increase of DAS28>0.6 and an absolute value of DAS28>2.6. The agreement between PRF and DBR was measured by the kappa coefficient on repeated data.

Results: In all, 137 patients were analyzed: mean age 55±11 years, females 78%, mean RA duration 9.5±8.0 years. Over the 18 months, PRF concerned 27.2% of the 940 available visits. DBR and PRF were observed in 24% and 16% of 940 visits for 137 patients respectively. All the items were associated with PRF with standardized effect size between -0.58 (SF36 PCS) and 0.87 (DAS28). The agreement between PRF and DBR was moderate (κ=0.44).

Conclusion: The concept of flare refers to more than just RA disease activity.

Keywords: Flares; Pain; Questionnaires; Rheumatoid arthritis; TNF-blockers.