Title : Optimising NELA risk stratification through enhanced accuracy in ASA grading
Abstract:
Background: Accurate ASA (American Society of Anaesthesiologists) grading is essential for perioperative risk assessment, anaesthetic planning, and surgical risk communication. It is also a key input in audit tools such as the National Emergency Laparotomy Audit (NELA) calculator [1]. At a district general hospital, Year 9 NELA data (1 December 2021-31 March 2023) recorded fifteen deaths, identifying it as a potential outlier for 30-day risk-adjusted mortality. Retrospective analysis showed systematic underestimation of ASA grades, resulting in lower NELA scores. This may delay recognition of high-risk patients, affect theatre planning, and compromise postoperative care such as HDU or ICU admission. In emergency cases, anaesthetists may consider the surgeon’s NELA estimate, including ASA grade, to support triage decisions. Underestimated risk may delay escalation or result in inappropriate prioritisation. We hypothesised this variability stemmed from inconsistent understanding of ASA criteria among both surgeons and anaesthetists.
Methods: A consultant-led teaching session was delivered to clinicians, covering ASA principles, common grading errors, and the clinical and audit implications of misclassification. Pre-intervention (Cycle 1), clinicians (n=25) completed a questionnaire assigning ASA grades to four anonymised vignettes drawn from the fifteen deaths in the audit cohort. Post-intervention (Cycle 2), the same questionnaire was repeated (n=6) to assess changes in grading accuracy and inter-rater agreement.
Results: Cycle 1 revealed significant inter-rater variability across both groups, with a trend toward underestimating ASA grades. Anaesthetist responses were generally more consistent than surgeons’, particularly in straightforward cases.
Following the teaching intervention (Cycle 2), grading accuracy and inter-rater agreement improved in both groups. Clinicians also reported increased confidence in ASA assignment. Feedback highlighted an improved awareness of how ASA grading influences NELA scoring, anaesthetic planning, and patient safety.
Discussion: While ASA grading is inherently subjective, structured multidisciplinary teaching improved clinicians’ understanding and reduced variability. This supports more accurate risk stratification, safer perioperative planning, and improved data quality. Anaesthetic-led initiatives can strengthen cross- specialty collaboration and promote shared responsibility for accurate preoperative assessment.
