Preoperative Hemoglobin A1c >7.5 Is Associated With Increased Bundled Payment Costs in Total Hip and Knee Arthroplasties.

INTRODUCTION

Studies have shown that patients with diabetes mellitus are at an increased risk for complications and higher episode-of-care costs after total hip (THA) and total knee arthroplasties (TKA), but the effect of poor glycemic control on episode-of-care costs has yet to be addressed in the literature. The purpose of this study was to determine whether patients with a higher preoperative hemoglobin A1c have increased episode-of-care costs in diabetic patients undergoing THA and TKA.

METHODS

We reviewed a consecutive series of 9,511 primary THA and TKA patients between 2015 and 2018. We recorded demographics, medical comorbidities, and hemoglobin A1c for patients with diabetes mellitus. We compared complications, readmissions, and 90-day episode-of-care costs from Medicare claims data across A1c levels. A multivariate logistic regression analysis was done to assess the independent effect of A1c on episode-of-care costs.

RESULTS

Diabetic patients (n = 1,042) had higher episode-of-care costs ($20,577 vs $19,414, P < 0.001) than patients without diabetes. Higher stratified A1c levels were associated with increasing mean episode-of-care costs (6.5% to 6.9% = $18,912; 7.0% to 7.49% = $19,832; 7.5% to 7.9% = $20,827; >8% = $21,169). In multivariate analysis, patients with hemoglobin A1c >7.5% had higher episode-of-care costs ($2,331, 95% confidence interval, $511-$4,151, P = 0.012). Those with a hemoglobin A1c >7.5% had increased rates of complications (7% vs 3%, P = 0.049) and readmissions (11% vs 5%, P = 0.020).

DISCUSSION

Hemoglobin A1c levels above 7.5% are associated with increased episode-of-care costs, complications, and readmissions after THA and TKA. Optimizing glycemic control before surgery may improve quality of care and lead to success in Medicare bundled payment models.