Predicting Adverse Outcomes After Total Hip Arthroplasty: A Comparison of Demographics, the American Society of Anesthesiologists class, the Modified Charlson Comorbidity Index, and the Modified Frailty Index

Introduction: No known study has compared the predictive power of the American Society of Anesthesiologists (ASA) class, modified Charlson Comorbidity Index, modified Frailty Index, and demographic characteristics for general health complications after total hip arthroplasty (THA). Methods: Comorbidity indices and demographics from National Surgical Quality Improvement Program THA patients were evaluated for discriminative ability in predicting adverse outcomes using the area under the curve analysis from the receiver operating characteristic curves. Perioperative outcomes included any adverse event, severe adverse events, minor adverse events, extended hospital stay, and discharge to higher-level care. Results: In total, 64,792 THA patients were identified. The most predictive comorbidity index was ASA, and demographic factor was age. Of these, age had the greatest discriminative ability for four of the five adverse outcomes. Conclusion: For THA, easily obtained patient ASA and age are more predictive of perioperative adverse outcomes than the more complex and numerically tabulated modified Charlson Comorbidity Index and modified Frailty Index.