Improving Accuracy of ASA Grading in Patients with Neck of Femur Fractures: A Closed-Loop Audit Incorporating the Clinical Frailty Scale

This is the authors' abstract. We don't add key points for this paper.

Introduction Accurate American Society of Anaesthesiologists (ASA) Physical Status classification is essential for peri-operative risk stratification in patients with neck of femur (NOF) fractures who are typically older, frail, and multimorbid. ASA is a key variable used within the National Hip Fracture Database (NHFD) to adjust for casemix when calculating expected mortality and benchmarking institutional performance. Inaccurate ASA grading may underestimate patient comorbidity and frailty, leading to artificially low expected mortality and misrepresentation of service outcomes. Aim To assess the accuracy of ASA grading in patients admitted with NOF fractures using the Clinical Frailty Scale (CFS), baseline mobility, and comorbidities, and to re-audit performance following targeted quality improvement interventions prompted by concerns regarding NHFD casemix adjustment. Methods Three audit cycles were undertaken at a UK district general hospital. This abstract reports Audit Cycle 3, with Audit Cycle 2 as the baseline comparator. ASA grades recorded in the NHFD were compared with revised ASA grades assigned following structured review of electronic patient records, incorporating documented comorbidities, baseline functional status, and CFS. Where CFS was not prospectively documented, frailty was assigned retrospectively from contemporaneous clinical documentation. Results In Audit Cycle 2 (n=129), ASA was underestimated in 33 patients (25.6%). In Audit Cycle 3 (n=114), underestimation reduced to 17 patients (14.9%), with no cases of overestimation. The most frequent discrepancy remained revision from ASA 3 to ASA 4. Prospective CFS documentation was absent throughout. Conclusion ASA underestimation improved but remains clinically significant. Persistent gaps in frailty documentation risk distortion of NHFD casemix-adjusted mortality. Embedding routine frailty assessment may improve outcome benchmarking.