Impact of the Addition of Examples to the American Society of Anesthesiologists Physical Status Classification System.

Abstract

Examples of comorbidities for the widely used American Society of Anesthesiologists physical status (ASA-PS) classification system were developed and approved in 2014. We conducted a retrospective cohort study of patients with 4 comorbidities included in the examples as warranting a specific minimum ASA-PS class. For each comorbidity subgroup, we used interrupted time-series models to compare ASA-PS underclassification for the periods before (2011-2014) and after (2015-2017) the introduction of examples. Rates of underclassification ranged from 4.8% to 38.7%. We observed no evidence of a significant impact on ASA-PS classification with the introduction of examples in 2014.