Cost of Depression in Japanese Patients with Rheumatoid Arthritis: Evidence from Administrative Data

Introduction: To determine the cost of depression comorbidity among Japanese adults with rheumatoid arthritis (RA). Methods: A retrospective database study of 8968 patients diagnosed with RA between 2010 and 2015 and treated with any RA medication was conducted. Health care utilization characteristics were compared between patients with and without a comorbidity of depression. Propensity score matching was applied to ensure a balanced comparison between the two cohorts. Results: The prevalence of a depression comorbidity was found for 5% of the total RA patients. This comorbidity was associated with 62% (56%) higher total outpatient visits and 66% (163%) higher rate of emergency room visits after 6 (12) months. Conclusions: Burden of depression among RA patients in Japan is relatively high and awareness for depression as a comorbidity of RA needs to be reinforced. Funding: Janssen Pharmaceutical KK.