ASA class is a reliable independent predictor of medical complications and mortality following surgery

Abstract Methods The American Society of Anesthesiologists Physical Status classification system (ASA PS) is a method of characterizing patient operative risk on a scale of 1–5, where 1 is normal health and 5 is moribund. Every anesthesiologist is trained in this measure, and it is performed before every procedure in which a patient undergoes anesthesia. We measured the independent predictive value of ASA-PS for complications and mortality in the ACS-NSQIP database by multivariate regression. We conducted analogous regressions after standardizing ASA-PS to control for interprocedural variations in risk in the overall model and sub-analyses by surgical specialty and the most common procedures. Results For 2,297,629 cases (2005–2012; median age 55, min = 16, max>90 [90 and above are coded as 90+]), at increasing levels of ASA-PS (2–5), odds ratios (OR's) from 2.05 to 63.25 (complications, p