Social risk and patient-reported outcomes after total knee replacement: Implications for Medicare policy

Objective: To determine whether county-level or patient-level social risk factors are associated with patient-reported outcomes after total knee replacement when added to the comprehensive joint replacement risk-adjustment model. Data Sources and Study Setting: Patient and outcomes data from the Function and Outcomes Research for Comparative Effectiveness in Total Joint Replacement cohort were merged with the Social Vulnerability Index from the Centers for Disease Control and Prevention. Study Design: This prospective longitudinal cohort measured the change in patient-reported pain and physical function from baseline to 12 months after surgery. The cohort included a nationally diverse sample of adult patients who received elective unilateral knee replacement between 2012 and 2015. Data Collection/Extraction Methods: Using a national network of over 230 surgeons in 28 states, the cohort study enrolled patients from diverse settings and collected one-year outcomes after the surgery. Patients <65 years of age or who did not report outcomes were excluded. Principal Findings: After adjusting for clinical and demographic factors, we found patient-reported race, education, and income were associated with patient-reported pain or functional scores. Pain improvement was negatively associated with Black race (CI = −8.71, −3.02) and positively associated with higher annual incomes (≥$45,00) (CI = 0.07, 2.33). Functional improvement was also negatively associated with Black race (CI = −5.81, −0.35). Patients with higher educational attainment (CI = −2.35, −0.06) reported significantly less functional improvement while patients in households with three adults reported greater improvement (CI = 0.11, 4.57). We did not observe any associations between county-level social vulnerability and change in pain or function. Conclusions: We found patient-level social factors were associated with patient-reported outcomes after total knee replacement, but county-level social vulnerability was not. Our findings suggest patient-level social factors warrant further investigation to promote health equity in patient-reported outcomes after total knee replacement.