ObjectivesTo identify factors associated with plasma D-dimer levels in outpatients with rheumatoid arthritis (RA).MethodsWe consecutively recruited 460 RA patients who visited our hospital for routine follow-ups between June and October 2021. Plasma D-dimer, RA-related characteristics, comorbidities, and cardiovascular and venous thromboembolism (VTE) risk factors were examined at enrolment. Patients with elevated D-dimer levels underwent whole-leg venous ultrasonography to diagnose deep vein thrombosis (DVT).ResultsParticipants had no DVT signs or symptoms. Among them, 252 (54.8%) were positive for plasma D-dimer (≥0.5 μg/ml) and 40 (8.7%) had high D-dimer levels (≥3 μg/ml). The mean was 1.07 μg/ml. After adjustments, age [odds ratio (OR) 1.88 per additional 10 years, P = .003], high and moderate clinical disease activity index (OR 8.79, P ConclusionsClinical disease activity is a major contributor to plasma D-dimer elevation in RA outpatients.