POS1143 GOUT AND JOINT REPLACEMENTS IN THE US
Authors: G. Singh, M. Sehgal, A. Mithal
Journal: Annals of the Rheumatic Diseases (2021)

Background: Irreversible joint damage in gout has been linked to a possible increase in knee and hip joint replacements 1 . In addition, the strong association between gout and osteoarthritis 2,3 could also lead to an increased risk of joint replacements in patients with gout. Population-based data from the UK and Taiwan have shown hazard rates of 1.14 and 1.16 respectively for knee replacements in patients with gout compared to age and gender matched controls 1 . However, there is little national data in the US on clinical and economic burden of joint replacements in patients with gout. Objectives: To evaluate total or partial hip and knee joint replacements in patients with gout in the US and to estimate their economic impact Methods: The Nationwide Inpatient Sample (NIS) is a stratified random sample of all US community hospitals. It is the only US national hospital database with information on all patients, regardless of payer, including persons covered by Medicare, Medicaid, private insurance, and the uninsured. Detailed information including clinical and nonclinical data elements on each hospital stay including International Classification of Diseases (ICD)10 diagnosis and procedure codes, age, gender, length of stay, payer, charges, comorbidities etc. is available. We examined hospitalizations in patients with gout with hip and knee joint replacements in NIS 2018, the most recent year of data. Results: In 2018, there were 914,510 hospitalizations with primary or secondary diagnosis of gout in the US. Of these 43,615 were for joint replacement surgeries (knee (24,840) and hip (18,755)). Patients with knee replacement were on an average 68.5 years old (95% confidence intervals 68.2 years -68.8 years). Patients with hip replacement were slightly older (mean age 70.3 years, 95% confidence intervals 69.8 years -70.7 years). Unlike general population statistics, men formed a majority of these joint replacements (68% for the knee and 72% for the hip). The average charge per hospitalization was $69,279 and $72,944 for knee and hip replacement respectively. The total annual national cost estimate was $3.09 billion, with government insurances (Medicare and Medicaid) responsible for 67% of knee replacement and 70% of hip replacement costs. Conclusion: Joint replacements in gout patients have a large clinical and economic burden in the US. This calls for an increased awareness and management of associated hip and knee arthritis in patients with gout. References: [1]Kuo CF, Chou IJ, See LC, et al. Urate-lowering treatment and risk of total joint replacement in patients with gout. Rheumatology. Dec 1 2018;57(12):2129-2139. [2]Howard RG, Samuels J, Gyftopoulos S, et al. Presence of gout is associated with increased prevalence and severity of knee osteoarthritis among older men: results of a pilot study. Journal of clinical rheumatology: practical reports on rheumatic &amp; musculoskeletal diseases. Mar 2015;21(2):63-71. [3]Roddy E, Zhang W, Doherty M. Are joints affected by gout also affected by osteoarthritis? Annals of the rheumatic diseases. Oct 2007;66(10):1374-1377. Disclosure of Interests: Gurkirpal Singh Shareholder of: Pfizer, Merck, Sanofi, Grant/research support from: Horizon, Maanek Sehgal: None declared, Alka Mithal: None declared.