Assignment of ASA-physical status relates to anesthesiologists’ experience: a survey-based national-study

BACKGROUND: The American Society of Anesthesiologists physical status (ASA-PS) is a grading system adopted worldwide by anesthesiologists to classify the overall health status of patients. Its importance is demonstrated not only by its routine use in clinical practice, but also by its deployment in other healthcare-related environments. However, a weak/moderate inter-rater reliability for ASA-PS has been previously shown, and although definitions and clinical examples of each class are provided by ASA, doubts remain on the individual factors influencing assignment to an ASA-PS class. The aim of this study was to investigate whether and how an anesthesiologist’s experience affects classification into a specific ASA-PS class. METHODS: An online survey presenting eight fictitious patients was administered to a group of Italian anesthesiologists and residents. Respondents were asked to assign each of the eight patients to a specific ASA-PS class. Anesthesiologists were subdivided into five classes according to years of experience as an anesthesiologist. RESULTS: Six hundred one surveys were correctly completed. The highest mean number of correct answers was obtained by residents (3.95 ± 1.13), with the number decreasing progressively with increasing work experience. The lowest value was recorded in the most experienced group (3.13 ± 1.25). Inter-rater reliability was weak/moderate in all experience level groups (k = 0.38). CONCLUSIONS: Low inter-reliability of the ASA-PS and the experience-dependence of the anesthesiologist in assigning classifications must be taken into account when evaluating a patient, particularly in settings where wide differences in experience are present.