569: Outpatient and Inpatient Costs of Knee Osteoarthritis in Brazil over 2024: A Cost-of-Illness Study

Topic: Education, Societal Impact, and Others
Subtopic: Economics

Background and Aims: Knee osteoarthritis is one of the leading causes of pain and disability worldwide, particularly among older adults(1). In Brazil, knee osteoarthritis is also high prevalent(1). Despite its high prevalence, evidence on the economic burden of knee osteoarthritis remains limited in low- and middle-income countries(2). Cost-of-illness studies are essential to estimate economic burden, identify major cost drivers, and support healthcare system in resource allocation(3). Thus, the aim of this study is to estimate the outpatient and inpatient care costs of knee osteoarthritis in the Brazilian Public Healthcare System (SUS) in 2024.

Methods: This cost-of-illness study was conducted from the SUS perspective with a time horizon of 12 months using a top-down approach. The outpatient and inpatient costs of knee osteoarthritis in 2024 were estimated using data from the Outpatient and Hospital Information Systems of the SUS. Data were extracted and processed in the TABWIN version.1.4.1, using the International Classification of Diseases, Tenth Revision (ICD-10) code M17 - knee osteoarthritis, with no restriction for age and sex. Descriptive analyses were conducted to report the quantities of resource used and outpatient and inpatient costs. The most common resource used was also reported.

Results: In 2024, the SUS recorded 2,580,894 outpatient visits and 17,597 hospital admissions related to knee osteoarthritis. Outpatient costs were around US$6.9 million, whereas inpatient costs were around US$36 million, indicating a substantially higher financial impact of inpatient care. Physiotherapy services and specialist consultations were the most frequently resource used and highest-cost outpatient procedures, accounting for 74% of total outpatient costs. In contrast, primary total knee arthroplasty accounted for the majority of hospital admissions and inpatient expenditures, representing 73% of total inpatient costs. Higher costs were observed among women and individuals aged 60-70 years in both care.

Conclusions: Knee osteoarthritis imposed a substantial economic burden on the SUS in 2024. Inpatient care accounted for the largest share of the healthcare costs, reflecting disease progression and the increasing need for resource-intensive interventions. The high volume of outpatient physiotherapy visits is consistent with clinical guideline recommendations(4), as exercise-based physiotherapy is a first-line treatment for knee osteoarthritis and supports long-term management of nociceptive pain5. Cost concentration among women and older adults aligns with the established epidemiological profile1, highlighting the public health relevance of knee osteoarthritis and the need for cost-effective care pathways within the nationwide impact.

References: 1. GBD 2019 Diseases and Injuries Collaborators. Global burden of 369 diseases and injuries in 204 countries and territories, 1990-2019: a systematic analysis for the Global Burden of Disease Study 2019. Lancet. 2020;396(10258):1204-1222.
2. Jin, X. et al. Economic and Humanistic Burden of Osteoarthritis: An Updated Systematic Review of Large Sample Studies. Pharmacoeconomics. 2023;41(11):1453-1467
3. Miyamoto, G.C. et al. Interpretation of trial-based economic evaluations of musculoskeletal physical therapy interventions. Braz J Phys Ther. 2021;25(5):514-529.
4. Moseng, T. et al. EULAR recommendations for the non-pharmacological core management of hip and knee osteoarthritis: 2023 update. Annals of the Rheumatic Diseases. 2024;83(6):730-740.

Presenting Author: Gabriela Coscrato De Lazzari Afonso
Submitting Author: Gabriela De Lazzari

Senior Author: Gisela Cristine Miyamoto

IASP 2026 Global Year theme of Neuropathic Pain: No

• Gisela Cristine Miyamoto: PhD - Ribeirão Preto Medical School, University of São Paulo (FMRP - USP)
• Yasmin Brasileiro de Souza: PhD Student - Ribeirão Preto Medical School, University of São Paulo (FMRP - USP)
• Frederico de Carvalho Barbosa Ferreira: MsC Student - Ribeirão Preto Medical School, University of São Paulo (FMRP - USP)