How well do pediatric anesthesiologists agree when assigning ASA physical status classifications to their patients?

The scope and application of the American Society of Anesthesiologists Physical Status (ASA PS) classification has been called into question and interobserver consistency even by specialist anesthesiologists has been described as only fair. Our purpose was to evaluate the consistency of the application of the ASA PS amongst a group of pediatric anesthesiologists. We randomly selected 400 names from the active list of specialist members of the Society for Pediatric Anesthesia. Respondents were asked to rate 10 hypothetical pediatric patients and answer four demographic questions. We received 267 surveys, yielding a response rate of 66.8% and the highest number of responses in any study of this nature. The spread of answers was wide across almost all cases. Only one case had a response spread of only two classifications, with the remaining cases having three or more different ASA PS classifications chosen. The most variability was found for a hypothetical patient with severe trauma, who received five different ASA PS classifications. The Modified Kappa Statistic was 0.5, suggesting moderate agreement. No significant difference between the private and academic anesthesiologists was found (P = 0.26). We present the largest evaluation of interobserver consistency in ASA PS in pediatric patients by pediatric anesthesiologists. We conclude that agreement between anesthesiologists is only moderate and suggest standardizing assessment, so that it reflects the patient status at the time of anesthesia, including any acute medical or surgical conditions.