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

Background: 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 shoulder arthroplasty (SA) in patients with and without renal disease. A secondary aim was to define the characteristics of patients with renal disease.

Methods: We conducted a retrospective cohort study of all patients who underwent primary SA 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 mL/min/1.73 m) and without CKD (GFR ≥60 mL/min/1.73 m). Univariate regression was performed to assess the influence of CKD on health care utilization, including LOS, transfusion, and risk for emergency department (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 estimated GFR on total 90-day encounter charges.

Results: A total of 514 patients met the study inclusion criteria, with 125 having CKD and 389 having normal GFR. Patients with CKD were more likely to require transfusion (odds ratio: 16.2 [confidence interval: 1.9, 139.7], P = .011) despite similar intraoperative estimated blood loss (156.9 ± 132.5 mL vs. 153.8 ± 89.7 mL; P = .768). In addition, patients with CKD had longer LOS (2.8 ± 1.3 days vs. 2.3 ± 1.0 days; P < .001), had higher 90-day readmission rates (P = .001), were more likely to visit the ED within 90 days after SA (P = .018), and had higher total 90-day encounter charges ($37,769 ± $6901 vs. $35,684 ± $5312; P = .001). Each unit increase in eGFR independently reduced total encounter charges by $67 (-$132, -$2; P = .043); dialysis patients incurred higher total 90-day encounter charges compared with patients with less severe renal disease ($42,733 ± $8985 vs. $37,531 ± $6749; P = .002). Also, patients with CKD were older (73.2 ± 8.9 vs. 68.1 ± 9.4 years; P < .001); had a lower preoperative hemoglobin level (12.4 ± 1.5 g/dL vs. 13.4 ± 1.5 g/dL; P < .001), higher American Society of Anesthesiologists score (P < .001), and more preoperative comorbidities (5.9 ± 2.9 vs. 5.0 ± 3.1; P < .001); and were more likely to use opioids preoperatively (P = .043).

Conclusion: Patients with CKD have a higher risk for blood transfusion, ED visits, and readmission after SA, 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.