Chronic kidney disease increases cost of care and readmission risk after shoulder arthroplasty

Abstract

Chronic kidney disease (CKD) is associated with adverse outcomes and higher costs after lower extremity arthroplasty from higher rates of infection, aseptic loosening, and transfusion and longer hospital length of stay (LOS). The purpose of this study was to compare health care utilization and 90-day encounter charges after SA in patients with and without renal disease. A secondary aim was to define patient characteristics of patients with renal disease. We conducted a retrospective cohort study of all patients who underwent primary shoulder arthroplasty from January 2015 to December 2019 by a single surgeon at a single institution. Patients without a baseline glomerular filtration rate (GFR) were excluded. We evaluated results for patients with CKD (GFR ≤59) and without CKD (GFR ≥60). Univariate regression was performed to assess the influence of CKD on healthcare utilization, including length of stay (LOS), transfusion, and risk for ED revisit or readmission during the 90-day postoperative period. In addition, 90-day encounter charges, revisit charges, and ED charges for patients with CKD were compared with those for patients with normal renal function. Last, multivariable linear regression models were used to assess the effect of eGFR on total 90-day encounter charges. 514 patients met the study inclusion criteria. 125 had CKD, 389 had normal GFR. Patients with CKD were more likely to require transfusion [OR 16.2 (1.9, 139.7), p=0.011] despite similar intraoperative estimated blood loss (156.9±132.5mL versus 153.8±89.7mL, p=0.768). In addition, CKD patients had longer LOS (2.8±1.3 days versus 2.3±1.0 days, p<0.001), had higher 90-day readmission rates (p=0.001), were more likely to visit the ED within 90 days after shoulder arthroplasty (p=0.018), and had higher total 90-day encounter charges ($37,769±$6,901 versus $35,684±$5,312, p=0.001). Each unit increase in eGFR independently reduced total encounter charges by $67 (-$132, -$2, p=0.043); dialysis patients incurred higher total 90-day encounter charges compared to patients with less severe renal disease ($42,733 ± $8,985 v. $37,531± $6,749, p=0.002). Also, patients with CKD were older (73.2±8.9 versus 68.1±9.4 years, p<0.001); had lower preoperative Hg (12.4±1.5g/dL versus 13.4±1.5g/dL; p<0.001), higher ASA score (p<0.001), and more preoperative comorbidities (5.9±2.9 versus 5.0±3.1, p=<0.001); and were more likely to use opioids preoperatively (p=0.043). Patients with CKD have a higher risk for blood transfusion, ED visits, and readmission after shoulder arthroplasty, with higher total 90-day encounter charges. Identifying and optimizing this patient population before surgery can reduce costs and improve outcomes, which benefits patients, physicians, institutions, and payors.