Which Socioeconomic Factors Affect Outcomes Following Total Hip and Knee Arthroplasty?

BACKGROUND: Studies have shown that lower socioeconomic status may result in adverse outcomes following total hip (THA) and total knee arthroplasty (TKA). The optimal method of defining socioeconomic status, however, continues to be debated. The purpose of this study is to determine which socioeconomic variables are associated with poor outcomes following THA and TKA. METHODS: We reviewed a consecutive series of 2770 primary THA and TKA patients from 2015 to 2018. Utilizing census data based upon the patient's ZIP code, we extracted poverty, unemployment, high school graduation, and vehicle possession rates. We collected demographics, comorbidities, discharge disposition, 90-day readmissions, and postoperative functional outcome scores for each patient. We then performed a multivariate regression analysis to identify the effect of each socioeconomic variable on postoperative outcomes. RESULTS: Patients from areas with high unemployment (P = .008) and low high school graduation rates (P = .019) had a higher age-adjusted Charlson Comorbidity Index. High poverty levels, high unemployment, lower high school graduation rate, and lower vehicle possession rates did not have a significant effect on functional outcomes (all P > .05). In the multivariate analysis, no socioeconomic variable demonstrated an increased rate of rehabilitation discharge, revision, or readmission (all P > .05). CONCLUSION: Patients undergoing THA and TKA from areas with high unemployment and lower educational levels do have more medical comorbidities. However, none of the 4 socioeconomic variables studied are independently associated with higher rates of readmission, discharge to rehabilitation, or worse functional outcomes. Patients from disadvantaged areas should not be denied access to arthroplasty care based on socioeconomic status alone.