The American Society of Anesthesiologists' class as a comorbidity index in a cohort of head and neck cancer surgical patients

Background. We assessed the American Society of Anesthesiologists' (ASA) class, as a measure of comorbidity in comparison to the commonly used Charlson index for prognostic ability in a HNCA population. Methods. Proportional hazards methods were applied to head and neck cancer patients whose treatment included surgery by the Johns Hopkins Otolaryngology service (n = 388). Results. The Charlson index and ASA class were modestly correlated (Spearman 0.36, p < .001). Compared with patients with ASA class 1 or 2, those with ASA class 3 or 4 had a two-fold elevated mortality rate (Relative Hazard (RH) = 2.00, 95% Cl, 1.36-2.89). This association was stronger than observed for a Charlson index score of 1 or more compared with 0 (RH = 1.59, 95% Cl, 1.17-2.17). Both the Charlson index and ASA class adjusted RHs displayed dose-response patterns (p value for trend <.001). Conclusions. Compared with the Charlson index, the ASA class had comparable if not greater prognostic ability for mortality in this elderly HNCA population. (C) 2001 John Wiley & Sons, Inc.