ASA Physical Status Classifications

TLDR

A questionnaire sent to 304 anesthesiologists asked them to classify ten hypothetical patients to assess consistency of ASA Physical Status Classification use. Among 255 respondents (77.3 %), the ASA classification was applied consistently to an average of 5.9 of 10 cases; however, four cases and factors such as age, obesity, prior myocardial infarction, and anemia produced wide rating variability, with academics outperforming private practitioners, while regional and billing differences were negligible, indicating the system is useful yet imprecise.

Abstract

The American Society of Anesthesiologists' (ASA) Physical Status Classification was tested for consistency of use by a questionnaire sent to 304 anesthesiologists. They were requested to classify ten hypothetical patients. Two hundred fifty-five (77.3 percent) responded to two mailings. The mean number of patients rated consistently was 5.9. Four patients elicited wide ranges of responses. Age, obesity, previous myocardial infarction, and anemia provoked controversy. There was no significant difference in responses from different regions of the country. Academic anesthesiologists rated a greater number identical than did those in private practice (P less than 0.01). There was no difference in ratings between those who used the classification for billing purposes and those who did not. The ASA Physical Status Classification is useful but suffers from a lack of scientific precision.