Self-reported flares are predictors of radiographic progression in rheumatoid arthritis patients in 28-joint disease activity score remission: a 24-month observational study

Background: Disease flares are common in rheumatoid arthritis (RA) and are related to structural damage. However, few data on the impact of flares reported by patients on radiographic progression are available. Our aim was to investigate whether overall flares (OF), self-reported flares (SRF) and short flares assessed at the visit (SF) predict radiographic progression in RA patients in DAS28 (28-joint disease activity score) remission.

Methods: We reviewed the records of RA patients included in our database. We considered all patients who had a period of at least 24 months in remission (DAS28 < 2.6), stable biologic and synthetic disease-modifying anti-rheumatic drug treatment, no missing follow-up visits and hands and feet radiographs at the start and at the end of the 24-month follow up. Radiographic progression was considered as an increase in the van der Heijde modified total Sharp score >0. Patients were assessed every 3 months and flares were recorded. We defined SRF as any worsening of the disease reported by patients occurring in the time between visits and SF as an increase in DAS28 ≥ 2.6 or >0.6 from the previous visit assessed by the physician in one isolated visit. The impact of SRF, SF and OF on radiographic progression was assessed through multivariate regression analysis.

Results: One hundred forty-nine patients were included. The median number (interquartile range) of OF was 1.00/year (0.50; 1.38), of SRF was 0.50/year (0.14; 1.00), and of SF was 0.34/year (0; 0.50). Eighteen patients (12.1 %) experienced a progression of radiographic damage. OF and SRF were significant predictors of radiographic progression: OR 3.27, 95 % CI 1.30, 8.22 and OR 3.63, 95 % CI 1.16, 11.36, respectively.

Conclusions: OF and SRF are predictors of structural damage. Flares assessed at the visit, SF, do not impact on radiographic progression as they might underestimate the actual number of flares.