Associations of Rheumatoid Arthritis Disease Activity With Frailty Over Five Years of Follow-up.

Abstract

To evaluate whether rheumatoid arthritis (RA) disease activity is associated with frailty both in cross-section and longitudinally. Participants within the Veterans Affairs Rheumatoid Arthritis (VARA) registry enrolled from 2003 to 2022 were included. The exposure was RA disease activity measured by the Disease Activity Score in 28 joints (DAS28) with erythrocyte sedimentation rate or C-reactive protein. DAS28 was collected at VARA registry enrollment, and the mean DAS28 score was calculated annually and categorized by level of disease activity. The outcome was frailty measured using the Veterans Affairs Frailty Index (VAFI), which was calculated annually from diagnostic and procedural codes. The relationship of DAS28 with VAFI score was examined at baseline and over five years of follow-up. Multivariable linear regression was used for cross-sectional analysis and generalized estimating equations evaluated the associations longitudinally. Of the 2,800 veterans, 89% were male, 76% were White, the mean age was 64 ± SD 11 years, average RA disease duration was 12 ± SD 11 years, and 28% were frail. A higher DAS28 score was associated with an increasing VAFI score at enrollment (adjusted β 0.86, 95% confidence interval [CI] 0.63-1.08, P < 0.001, N = 2,800). RA disease activity scores were independently associated with frailty scores over five years of follow-up (adjusted β 0.53, 95% CI 0.26-0.80, P < 0.001, n = 2,786). Higher RA disease activity was associated with increased frailty burden over time. Future studies should assess whether achieving low disease activity or remission can impact frailty burden over time.