Socioeconomic Deprivation and Outcomes After Total Joint Arthroplasty: An Analysis of the American Joint Replacement Registry Using the Area Deprivation Index.

Abstract

There is increasing interest in socioeconomic deprivation and its influence on outcomes in orthopaedics. This study aimed to examine the relationship between neighborhood-level social deprivation and its impact on 90-day readmission, length of stay, and all-cause revision after primary total knee arthroplasty (TKA) and total hip arthroplasty (THA). A retrospective cohort study was conducted using data from the American Joint Replacement Registry merged with the Centers for Medicare and Medicaid Services claims for patients 18 and over who had undergone primary unilateral TKAs and THAs. Comparisons were performed between patients grouped into Area Deprivation Index (ADI) quartiles by ZIP code (Quartiles 1 to 4, with Quartile 1 being the least disadvantaged). Subanalyses were performed using multinomial logistic regression and Cox proportional hazard models for outcomes with Quartile 1 serving as reference. A total of 1,654,680 TKA and 1,051,311 THA procedures met the inclusion criteria. Unadjusted analysis demonstrated significant differences in all outcomes based on ADI quartile (P < 0.001 for all outcomes except TKA all-cause revision, P = 0.003). In a subanalysis, Quartile 4 was significantly more likely to undergo readmission within 90 days for TKA (hazard ratio 1.631; 95% CI [confidence interval]: 1.528 to 1.741, P < 0.0001) and THA (HR 1.513; 95% CI: 1.406 to 1.629, P < 0.0001). For LOS, Quartile 4 was significantly more likely to stay more than three days versus one day for TKA (OR 1.103; 95% CI: 1.053 to 1.155, P < 0.0001) and THA (OR 1.401; 95% CI: 1.312 to 1.496, P < 0.0001). There was a significant increase in all-cause revision for Quartile 4 for THA (HR 1.082, 95% CI: 1.008 to 1.162, P = 0.03), but no significant difference for TKA. Socioeconomic deprivation as measured by the ADI is associated with increased 90-day readmission, LOS, and all-cause revision after total joint arthroplasty. These findings support the need to address socioeconomic disparities in arthroplasty, both in risk stratification and in initiatives that support providers and systems treating disadvantaged populations at risk for increased resource utilization.