Abstract
INTRODUCTION: In patients with rheumatoid arthritis (RA), attaining remission or low disease activity (LDA), as recommended by the treat-to-target approach, has shown to yield improvement in symptoms and quality of life. However, limited evidence from real-world settings is available to support the premise that better disease control is associated with lower healthcare costs. This study fills in evidence gaps regarding the cost of care by RA disease activity (DA) states and by therapy. METHODS: This retrospective cohort study linked medical and prescription claims from Optum Clinformatics Data Mart to electronic health record data from Illumination Health over 1/1/2010-3/31/2020. Mean annual costs for payers and patients were examined, stratifying on DA state and baseline use of conventional synthetic disease-modifying antirheumatic drugs (csDMARDs), biologics, and targeted synthetic (ts)DMARDs. Subgroup analysis examining within-person change in costs pre- and post-initiation of new therapy was also performed. Descriptive statistics, means, and boot-strapped confidence intervals were analyzed by DA state and by RA therapy. Furthermore, multivariate negative binomial regression analysis adjusting for key baseline characteristics was conducted. RESULTS: Of 2339 eligible patients, 19% were in remission, 40% in LDA, 29% in moderate DA (MDA), and 12% in high DA (HDA) at baseline. Mean annual costs during follow-up were substantially less for patients in remission ($40,072) versus those in MDA ($56,536) and HDA ($59,217). For patients in remission, csDMARD use was associated with the lowest mean annual cost ($25,575), tsDMARD was highest ($75,512), and tumor necrosis factor inhibitor (TNFi) ($69,846) and non-TNFi ($57,507) were intermediate. Among new TNFi (n = 137) and non-TNFi initiators (n = 107), 31% and 26% attained LDA/remission, respectively, and the time to achieve remission/LDA was numerically shorter in TNFi vs. non-TNFi initiators. For those on biologics, mean annual within-person medical and inpatient costs were lower after achieving LDA/remission, although pharmacy costs were higher. CONCLUSIONS: Cost of care increased with increasing DA state, with patients in remission having the lowest costs. Optimizing DA has the potential for substantial savings in healthcare costs, although may be partially offset by the high cost of targeted RA therapies.