Comparative evaluation of ASA classification and ACE-27 index as morbidity scoring systems in oncosurgeries

The primary intention of the study was to find out whether Adult Comorbidity Evaluation Index (ACE-27) was better than the American Society of Anaesthesiologists' (ASA) risk classification system in predicting postoperative morbidity in head and neck oncosurgery. Another goal was to identify other risk factors for complications which are not included in these indexes. Univariate and multivariate analyses were performed on 250 patients to determine the impact of seven variables on morbidity-ACE-27 grade, ASA class, age, sex, duration of anaesthesia, chemotherapy and radiotherapy. In univariate analysis ACE-27 index, ASA score, duration of anaesthesia, radiotherapy and chemotherapy were significant. As both comorbidity scales were significant in univariate analysis they were analyzed together and separately in multivariate analysis to illustrate their individual strength. In the first multivariate analysis (excluding ACE-27 grade) ASA class, duration of anaesthesia, radiotherapy and chemotherapy were significant. The positive predictive value (PPV) of this model to predict morbidity was 60.86% and negative predictive value (NPV) was 77.9%. The sensitivity was 75% and specificity 62.2%. In the second multivariate analysis (excluding ASA class) ACE-27 grade, duration of anaesthesia and radiotherapy were significant. The PPV of this model to predict morbidity was 62.1% and NPV was 76.5%. The sensitivity was 61.6% and specificity 70.9%. In the third multivariate analysis which included both ACE-27 grade and ASA class only ASA class, duration of anaesthesia, radiotherapy and chemotherapy remained significant. In conclusion, ACE-27 grade and ASA class were reliable predictors of major complications but ASA class had more impact on complications than ACE-27 grade.