Addressing Inter-Rater Variability in the ASA-PS Classification System

Abstract

Introduction: The American Society of Anesthesiologists' Physical Status (ASA-PS) Classification System was established to grade a patient's physical status prior to surgery. The literature shows inconsistencies in the application of the ASA-PS classification among providers. The many uses of the ASA-PS class require reliable ASA-PS class designations between providers. While much literature illustrates the inconsistency, there is limited research on how to improve inter-rater agreement. Material and Methods: Following an educational intervention targeted at medicine providers, a retrospective chart review was completed to determine the long-term impact of an educational intervention on ASA-PS class agreement among providers of different specialties. To assess the overall agreement between the data sets following the intervention, kappa statistics were calculated for the medicine and anesthesia data sets. These values were compared to the kappa statistics from a similar study completed prior to the educational intervention. Results: Overall, the kappa score, or agreement, between medicine and anesthesia providers improved from the range generally accepted to indicate slight agreement to the range indicating moderate agreement. Conclusions: While there was improvement in agreement following an education intervention, the agreement seen was not statistically significant. More research needs to be done to determine how to improve inter-rater reliability of the ASA-PS classification system with a focus on non-anesthesia providers.