Socioeconomic factors affecting outcomes in total shoulder arthroplasty

Abstract

BackgroundA lack of comprehensive research on socioeconomic factors affecting total shoulder arthroplasty (TSA) outcomes has demonstrated the need for further study. The purpose of this study is to determine the effects of socioeconomic factors such as ethnicity, income, and insurance status on the outcomes following TSA. MethodsAll anatomic TSA and reverse TSA cases from the National Inpatient Sample (NIS; N = 128,376) database from 2011 to 2019 as well as the Nationwide Readmission Database (NRD; N = 103,023) from 2010 to 2019 were analyzed. Self-identified ethnicities assessed in NIS included Caucasian (CC), African American (AA), and Hispanic (H), and ethnicities were compared to Caucasians. NRD cases were assessed by insurance status (Medicare, Medicaid, and private) and zip code income Quartiles (Q1-4, with Q1 being the lowest). Insurance types and Q1-3 were compared to private insurance and Q4, respectively. Demographic data, quantitative variables, and binary categorical variables were analyzed using chi-square test of independence, one-way ANOVA with Tukey-Kramer post hoc analyses, and binary logistic regression, respectively. ResultsFor NIS, AA had the highest percent Q1 and comorbidities of all ethnicities (P < .001), increased lengths of stay and hospital stay extensions (both P < .001). The majority of H were Q1 (P < .001) with increased comorbidities (P < .001), lengths of stay (P < .001), stay extensions (P = .027) and complications (P = .043). For NRD, Medicare patients had a 1.5 times higher mean comorbidity score (P < .001) and increased risk of complication (P = .007), readmission (P < .001), revision (P = .028), hospital stay extension (P < .001), and discharge to a new facility (P < .001). Similarly, Medicaid patients had a 1.6 times increased mean comorbidity score (P < .001), and the highest risk of the following adverse outcomes: length of stay extension (odds ratio [OR]: 1.43, P < .001), complication (OR: 1.24, P = .017), and readmission (OR: 1.18; P = .041). Additionally, they had an increased risk of discharge to a new facility (OR: 1.78, P < .001). Comparing TSA patients in the Q1-3 to Q4, first quartile income was significantly associated with increased risk of hospital stay extension (P = .043), complication (P < .001), and readmission (P < .001). Second and third quartile patients had increased risks of any complication (Q2: P = .003; Q3: P = .016). ConclusionThe socioeconomic factors studied - ethnicity (AA and H), zip code income (Q1, Q2, and Q3), and insurance status (Medicare or Medicaid) - were all shown to have significantly increased risk for adverse outcomes following TSA. Private insurance status, CC, and zip code income Q4 were all predictive of significantly less adverse outcomes. Further study is needed to assess specific social differences associated with these results.