Modifiable risk factors increase length of stay and 90-day cost of care after shoulder arthroplasty.

Background: Baseline health conditions can negatively impact cost of care and risk of complications after joint replacement, necessitating additional care and incurring higher costs. Bundled payments have been used for hip and knee replacement and the Centers for Medicare & Medicaid Services (CMS) is testing bundled payments for upper extremity arthroplasty. The purpose of this study was to determine the impact of predefined modifiable risk factors (MRFs) on total encounter charges, hospital length of stay (LOS), related emergency department (ED) visits and charges, and related hospital readmissions within 90 days after shoulder arthroplasty.

Methods: We queried the electronic medical record (EPIC) for all shoulder arthroplasty cases under DRG 483 within a regional 7-hospital system between October 2015 and December 2019. Data was used to calculate mean LOS, total 90-day charges, related emergency department (ED) visits and charges, and related hospital readmissions after shoulder arthroplasty. Data for patients who had 1 or more MRFs, defined as anemia (hemoglobin < 10 g/dL), malnutrition (albumin < 3.4 g/dL), obesity (BMI > 40), uncontrolled diabetes (random glucose > 180 mg/dL or glycated hemoglobin > 8.0%), tobacco use (International Classification of Diseases, Tenth Revision, code indicating patient is a smoker), and opioid use (opioid prescription within 90 days of surgery), were evaluated as potential covariates to assess the relationship between MRFs and total encounter charges, LOS, ED visits, ED charges, and hospital readmissions.

Results: A total of 1317 shoulder arthroplasty patients were identified. Multivariable analysis demonstrated that anemia (+$19,847, confidence interval [CI] $15,743, $23,951; P < .001), malnutrition (+$5850, CI $3712, $7988; P < .001), and obesity (+$2762, CI $766, $4758, P = .007) independently contributed to higher charges after shoulder arthroplasty. Mean LOS was higher in patients with anemia (5.0 ± 4.0 days vs. 2.2 ± 1.6 days, P < .001), malnutrition (3.7 ± 2.8 days vs. 2.2 ± 1.5 days, P < .001), and uncontrolled diabetes (2.8 ± 2.8 days vs. 2.3 ± 1.7 days, P = .019). Univariate risk factors associated with a significant increase in total 90-day encounter charges included anemia (+$19,345, n = 37, P < .001), malnutrition (+$6971, n = 116, P < .001), obesity (+$2615, n = 184, P = .011), and uncontrolled diabetes (+$4377, n = 66, P = .011). Univariate risk for readmission within 90 days was higher in patients with malnutrition (odds ratio 3.0, CI 1.8, 4.9; P < .001).

Conclusion: Malnutrition, obesity, and anemia contribute to significantly higher costs after shoulder arthroplasty. Medical strategies to optimize patients before shoulder arthroplasty are warranted to reduce total 90-day encounter charges, length of stay, and risk of readmission within 90 days of surgery. Optimizing patient health before shoulder surgery will positively impact outcomes and cost containment for patients, institutions, and payors after shoulder arthroplasty.