Social Determinants of Health Are Associated With Increased Risk of Preoperative Methicillin-Resistant Staphylococcus aureus Colonization in Patients Undergoing Total Joint Arthroplasty

Background Social determinants of health (SDOH) are associated with disparities in health outcomes and increased vulnerability to infectious diseases. This study evaluated the association between SDOH and methicillin-resistant Staphylococcus aureus (MRSA) colonization in patients undergoing primary total hip arthroplasty (THA), total knee arthroplasty (TKA), or total shoulder arthroplasty (TSA). Methods A retrospective cohort study was conducted using the United States TriNetX Research Network. Adults aged 18 years or older who underwent primary THA, TKA, or TSA were identified. Propensity score matching was performed using demographic variables and comorbidities. MRSA colonization rates were compared using risk ratios (RRs) with 95% confidence intervals (CIs), and subanalyses were conducted by joint type and age group. Cox regression evaluated independent risk predictors. Results SDOH were associated with a significantly higher risk of preoperative MRSA colonization across all joint types, including THA (2.2% vs 0.8%; RR, 2.74; 95% CI, 1.85–4.04), TKA (2.4% vs 1.1%; RR, 2.16; 95% CI, 1.60–2.92), and TSA (3.0% vs 1.6%; RR, 1.95; 95% CI, 1.16–3.29) (all P ≤ .01). In Cox proportional hazards models, increased hazard of preoperative MRSA colonization was observed with male sex, obesity, and prior surgical history (hazard ratio range, 1.14–2.84). Additional comorbidities, including alcohol abuse, psychoactive substance abuse, chronic obstructive pulmonary disease, and immune disorders, were also associated with increased hazard over time. Conclusions Social disadvantage was associated with an increased risk of MRSA colonization among patients undergoing primary total joint arthroplasties. These findings highlight the need for increased SDOH documentation and incorporation into preoperative risk stratification and infection prevention strategies. Level of Evidence III