Tabriz University of Medical Sciences Depiction of Health 2008-9058 17 3 2026 09 30 Analysis of the Cost of Illness and Determinants of Economic Burden in Inpatients and Outpatients with Rheumatoid Arthritis: A Retrospective Descriptive-Analytic Study 260 274 10.34172/doh.2026.21 EN Shabnam Nahani https://orcid.org/0009-0001-3323-2137 Mohammadreza Siahi-Shadbad https://orcid.org/0000-0003-3058-9488 Afshin Gharekhani https://orcid.org/0000-0003-1791-9120 Sama Samankan https://orcid.org/0000-0001-8920-4154 Mina Golestani https://orcid.org/0000-0003-0453-1354 Zohreh Siahi-Shadbad https://orcid.org/0009-0007-1190-0046 Mehdi Jafarpour https://orcid.org/0009-0008-3555-8908 Journal Article 10.34172/doh.2026.21 2026 06 18 2026 09 21 Background. Rheumatoid arthritis (RA) is a chronic inflammatory disease that imposes a significant economic burden on patients and the health system. Cost-of-illness studies are essential tools for estimating this burden and identifying associated factors. This study aimed to estimate the costs of illness and the factors influencing the economic burden of rheumatoid arthritis in hospitalized and outpatient individuals. Methods. This descriptive-analytical, retrospective, and single-center cost-of-illness study was conducted from the perspectives of the patient and society with a one-year time horizon (2024-2025 / 1403-1404) at Imam Reza Hospital in Tabriz. Data were gathered using medical records and a researcher-developed checklist, and all eligible patients were consecutively enrolled. Costs were estimated using a bottom-up approach. Data analysis was performed using SPSS version 26 via Shapiro-Wilk, Spearman, and Mann-Whitney U tests, considering a significance level of less than 0.05. Results. The study evaluated 48 outpatients and 124 hospitalized patients. The average direct medical costs for hospitalized patients and outpatients were 267,784 and 23,206 thousand Rials, respectively, while direct non-medical costs were 16,250 and 1,500 thousand Rials. Hospitalization and the use of biological drugs (bDMARDs) were significantly associated with increased total costs; specifically, costs were 183 percent higher in recipients of biological drugs (P=0.045). Insurance type was also associated with costs, and the out-of-pocket payment share for patients covered by the armed forces insurance was 12.5 percent lower than other insurance groups (P<0.001). Conclusion. Rheumatoid arthritis imposes a substantial economic burden that is significantly correlated with the type of treatment and hospitalization status. Biologic medications are primary drivers of increased costs; therefore, strengthening insurance coverage and optimizing the utilization of these drugs can assist in managing the economic burden of the disease. Research Insights · The costs of inpatients with rheumatoid arthritis are significantly higher than those of outpatients. · Direct medical costs account for the largest share of the economic burden of the disease. · The use of biologic drugs is one of the most important factors in increasing treatment costs. The type of insurance coverage has a significant impact on the amount of out-of-pocket payments for patients. · Early management of the disease and the rational use of biologic drugs can reduce the overall economic burden of the condition.