Background Patients and physicians often differ in their perceptions of rheumatoid arthritis (RA) disease activity, as quantified by the patient's global assessment (PGA) and by the evaluator's global assessment (EGA). The quest for understanding the reasons for discrepancies in evaluations of disease activity becomes particularly important in the context of recent recommendations that define Boolean-based ACR EULAR remission as the treatment target.
Objectives The objectives of this study were:
1) to explore the extent and reasons for this discordance
2) to determine if this discordance at baseline is associated with RA outcomes at 1 year (remission, function and structure) in early RA in daily clinical practice.
Methods Patients: from the French cohort of EA ESPOIR (at least 2 swollen joints for less than 6 months, DMARD naïve), fulfilling the ACR-EULAR criteria for RA at baseline
Analyses: At baseline, agreement between PGA and EGA (Bland-Altman plot) was assessed. Multivariate linear regression was used to determine the patient and EA features independently associated with discordance (calculated as PGA − EGA). Logistic regression was used to analyze discordance as |PGA − EGA| ≥20. Multivariate logistic models were used to determine if discordance at baseline is associated with remissions (Boolean, SDAI and DAS28), functional stability (HAQ ≤0.5 and deltaHAQ ≤0.25) and absence of radiographic progression (delta Sharp score <1) after 1 year of follow-up.
Results In 645 patients with ERA (mean age=48.8±12.2 years, 77% female, 48.7% ACPA+) agreement was better at both ends of the spectrum, especially for patients with high disease activity. Evaluation of disease activity yielded discordant scores between the patients and their physicians in 30% of our cohort: 153 patients (24%) had higher PGA scores, 41 patients (6%) had higher EGA scores, and 451 patients (70%) had concordant PGA and EGA scores (|PGA − EGA| <20).
In multivariate linear regression center-adjusted, higher PGA has been found to be associated with absence of fulfilling ACR 1987 revised criteria for RA (p=0.0005), higher levels of fatigue (p<0.0001) and lower number of swollen joint counts (SJC) (p=0.0022). With logistic regression center-adjusted, low number of SJC (OR [95% CI]: 1.92 [1.26–2.91]), low mental component of the SF-36 (OR [95% CI]: 1.82 [1.23–2.69]) and living alone (OR [95% CI]: 1.68 [1.09–2.58]) were associated with discordance between PGA and EGA.
In multivariate analyses, discordance at baseline was not associated with remission, function and structural progression at 1 year.
Conclusions In early RA, the discordance between PGA and EGA is multifactorial with objective measures like low SJC and absence of ACR 1987 revised criteria for RA, but also patient reported outcomes like high level of fatigue and low mental status, and environmental factor: living alone. Discordance between PGA and EGA at baseline was not associated with RA outcomes at 1 year. Understanding the reasons for a discordant view of disease activity will help to facilitate the sharing of decision-making in the management of RA.
Disclosure of Interest None declared