The Incidence, Prevalence, and Associated Costs of Anemia, Malignancy, Venous Thromboembolism, Major Adverse Cardiovascular Events, and Infections in Rheumatoid Arthritis Patients by Treatment History in the United States

OBJECTIVE: Comorbidities in rheumatoid arthritis (RA) can influence treatment selection, impact treatment persistency, and increase health care costs. This study assessed the magnitude of comorbidity burden via epidemiology (incidence and prevalence) and associated costs of select comorbidities in RA patients: anemia, malignancy, venous thromboembolism (VTE), major adverse cardiovascular events (MACE), and infections, stratified by history of disease‐modifying antirheumatic drug (DMARD) exposure. METHODS: From the IQVIA PharMetrics® Plus database, we selected adult patients with RA (2 or more RA diagnostic codes at least 30 days apart) at initiation of a new DMARD (DMARD‐naïve), after the first conventional synthetic DMARD (csDMARD) or after the first biologic DMARD (bDMARD). We assessed pre‐index prevalence (percentage) and on‐treatment incidence (per 100 patient‐years [P100PY]) of the aforementioned comorbidities. For patients with versus without incident conditions, we compared total all‐cause health care costs as unadjusted and adjusted for baseline characteristics and health care costs. RESULTS: Prior to initiating a new treatment, among DMARD‐naïve patients (N = 28,201), csDMARD switchers (N = 7,816), or bDMARD switchers (N = 4,656), the overall prevalence ranged from 14.1% to 16.2% (anemia), from 1.3% to 5.2% (malignancy, evaluated in csDMARD and bDMARD switchers), from 1.5% to 2.1% (VTE), from 1.8% to 2.9% (MACE), and from 66.6% to 76.1% (infections). Once on index treatment, overall incidence (P100PY) among the cohorts ranged from 6.9 to 8.9 (anemia), from 2.0 to 2.3 (malignancy), from 0.7 to 0.9 (VTE), from 1.6 to 2.0 (MACE), and from 77.4 to 87.7 (infections). The incident comorbidities (except herpes zoster) were associated with increased adjusted health care costs. CONCLUSION: Anemia, malignancy, VTE, MACE, and infections affect patients with RA at all stages of their treatment journey and are associated with increased health care costs.