Insurance Status Affects In-Hospital Complication Rates After Total Knee Arthroplasty

Insurance status has been shown to be a predictor of patient morbidity and mortality. The purpose of this study was to evaluate the effect of patient insurance status on the in-hospital complication rates following total knee arthroplasty. Data were obtained from the Nationwide Inpatient Sample (2004 through 2011). Patient demographics and comorbidities were analyzed and stratified by insurance type. Analysis was performed with a matched cohort comparing complication rates between patients with Medicare vs private insurance using the coarsened exact matching algorithm and multivariable logistic regression. A total of 1,352,505 patients (Medicare, 57.8%; private insurance, 35.6%; Medicaid/uninsured, 3.1%; other, 3.3%; unknown, 0.2%) fulfilled the inclusion criteria. The matched cohort analysis comparing Medicare with privately insured patients showed significantly higher risk of mortality (relative risk [RR], 1.34; P<.001), wound dehiscence (RR, 1.32; P<.001), central nervous system complications (RR, 1.16; P=.030), and gastrointestinal complications (RR, 1.13; P<.001) in Medicare patients, whereas privately insured patients had a higher risk of cardiac complications (RR, 0.93; P=.003). Independent of insurance status, older patients and patients with an increased comorbidity index were also associated with a higher complication rate and mortality following total knee arthroplasty. These data suggest that insurance status may be considered as an independent risk factor for increased complications when stratifying patients preoperatively for total knee replacement. Further research is needed to investigate the disparities in these findings to optimize patient outcomes following total knee arthroplasty. [Orthopedics. 2018; 41(3):e340-e347.].