Assessing the Predictive Accuracy of Popular Comorbidity Indices in Total Ankle Arthroplasty Outcomes

• Published in: Foot & ankle orthopaedics 2024-12, Vol.9
• Main Authors: Weston E. McDonald BS, Alexander S. Guareshi BS, Joshua L. Morningstar BS, Daniel J. Scott MBA, MD, Christopher E. Gross MD
• Format: Article
• Language: English
• ISSN: 2473-0114
• DOI: 10.1177/2473011424S00153

Category: Ankle; Ankle Arthritis Introduction/Purpose: As the incidence of TAA increases, identifying ways to stratify a patient’s risk for adverse outcomes becomes imperative. Two potential tools, the Charlson Comorbidity Index (CCI) and Elixhauser Comorbidity Index (ECI), have been widely supported and utilized across various fields of medicine and orthopaedic surgery. Despite encouraging results in TAA literature, the validity of the CCI and ECI as predictive tools for postoperative complications and functional outcomes following TAA remains ultimately unexplored. This study aims to describe and compare the predictive capacity of the CCI and ECM on the outcomes of TAA to further understand the reliability of such comorbidity indices in orthopaedic research. Methods: The Nationwide Readmissions Database (NRD) was queried from 2015 to 2020 to identify 29,705 patients undergoing primary TAA. Patients’ comorbidity was measured via CCI and ECI score, with patients who experienced adverse postoperative outcomes (any complication, readmission, mortality, extended length of stay (LOS), and adverse discharge) identified. Each index’s predictive ability was measured using the c statistic, a measure of area under the receiver operating characteristic curve (AUC). The value for AUC ranges from 0.50 to 1.0, indicating the discriminative ability of each index in assigning probability of the examined outcome, with 0.50 indicating no ability to discriminate and 1.0 indicating perfect ability to discriminate. AUC was categorized into poor (AUC