A Nationwide Analysis of the Impact of Socioeconomic Status on Complications and Healthcare Utilizations After Total Knee Arthroplasty Using the Area Deprivation Index: Consideration of the Disadvantaged Patient.

INTRODUCTION: Socioeconomic status (SES) has been demonstrated to be an important prognostic risk factor among patients undergoing total joint arthroplasty. We evaluated patients living near neighborhoods with higher socioeconomic risk undergoing total knee arthroplasty (TKA) and if they were associated with differences in: 1) medical complications; 2) emergency department (ED) utilizations; 3) readmissions; and 4) costs of care.

METHODS: A query of a national database from 2010 to 2020 was performed for primary TKAs. The Area Deprivation Index (ADI) is a weighted index comprised of 17 census-based markers of material deprivation and poverty. Higher numbers indicate a greater disadvantage. Patients undergoing TKA in zip codes associated with high ADI (90%+) were 1:1 propensity-matched to a comparison group by age, sex, and Elixhauser Comorbidity Index (ECI). This yielded 225,038 total patients, evenly matched between cohorts. Outcomes studied included complications, ED utilizations, readmission rates, and 90-day costs. Logistic regression models computed the odds ratios (OR) of ADI on the dependent variables. P-values less than 0.003 were significant.

RESULTS: High ADI led to higher rates and odds of any medical complications (11.7 versus 11.0%; OR: 1.05, P = 0.0006), respiratory failures (0.4 versus 0.3%; OR: 1.28, P = 0.001), and acute kidney injuries (1.7 versus 1.5%; OR: 1.15, P < 0.0001). Despite lower readmission rates (2.9 versus 3.5%), high ADI patients had greater 90-day ED visits (4.2 versus 4.0%; OR: 1.07, P = 0.0008). The 90-day expenditures ($15,066 versus $12,459; P < 0.0001) were higher in patients who have a high ADI.

CONCLUSION: Socioeconomically disadvantaged patients have increased complications and ED utilizations. Neighborhood disadvantage may inform healthcare policy and improve post-discharge care. The SES metrics, including ADI (which captures community effects), should be used to adequately risk-adjust or risk-stratify patients so that access to care for deprived regions and patients is not lost.