Use of the American Society of Anesthesiologists Physical Status Classification in non-trauma surgical versus trauma patients: a survey of inter-observer consistency

Background: The American Society of Anesthesiologists-Physical Status (ASA-PS) Classification is a grading system for classifying surgical patients based on their co-morbid background. Despite numerous benefits, its highly subjective nature has led to marked inconsistency when used. The purpose of this study was to assess consistency when public sector anaesthetists score trauma and non-trauma surgical patients using the Classification.Methods: A three-part questionnaire, with 18 clinical scenarios, was administered to 98 anaesthetists requiring them to grade the scenarios using the Classification and give their opinion on its usage.Results: A total of 97 completed questionnaires were received. Some 88% of respondents routinely use the Classification and 52% had read the Classification within the last 6 months. Many limitations of the use of the ASA system were identified. There was a lack of consistency in the scoring of the scenarios, with each scenario receiving at least three different gradings. Scenarios involving trauma, paediatrics, neurosurgery and the airway were associated with greater inconsistency. There was a statistically significant (p < 0.01) difference in inter-rater variability between the trauma and non-trauma scenarios.Conclusion: The ASA PS Classification shows poor inter-rater consistency when trauma patients are scored compared with non-trauma patients. Anaesthetists found it overall an inadequate tool to be used perioperatively in its current state. There has been a suggestion for a possible multifactorial modification with an aim to improve preoperative physical status and risk assessment of patients.