Application of APACHE II in the assessment, classification of severity and predictive ability of Chinese patients presenting to an emergency department resuscitation room

Objectives: To evaluate the use of APACHE II (Acute Physiology and Chronic Health Status Evaluation) in Chinese patients managed in the resuscitation room of an Accident & Emergency Department of one of the teaching hospitals in Hong Kong. Design: Prospective study on Chinese patients. Setting: Resuscitation Room in an Accident & Emergency Department of a university hospital in Hong Kong. Patients and measurements: Consecutive patients managed in the resuscitation room between 14th August, 2000 and 20th August 2000 (excluding patients younger than 18 years old and patients who were not admitted to hospital after initial assessment and treatment). For each patient, demographic data, diagnosis, the chronic health points, and the worst physiological parameters in the A&E resuscitation room were recorded. The total APACHE II scores and the probability of death were calculated. The accuracy of APACHE II for predicting group mortality was assessed by receiver operating characteristic curve analysis and linear regression analysis. Results: Of the 88 patients included in the study, 13 (15%) died and 75 (85%) survived. Significant factors associated with mortality included age, mean arterial pressure, heart rate, respiratory rate, arterial pH, serum sodium, Glasgow coma score, and chronic health points. For the three scoring subdivisions of APACHE II – total APS score, age points and chronic health points – higher mean values were found in those patients who died compared with patients who survived. Using logistic regression analysis, the APACHE II score determined in the emergency resuscitation room is a strong predictor of mortality (r=0.712). At a cut off score of >28 the sensitivity is 100.0% (95% CI 100.0-100.0), specificity is 68.0% (95% CI 56.278.3), positive likelihood ratio is 3.13, positive predictive value is 35.1 and negative likelihood ratio is 100.0. Analysis of the ROC curve reveals an area under the curve of 0.910 (95% CI 0.829-0.960). In patients not admitted to ICU, there was a positive correlation between APACHE score and length of hospital stay in patient who survived (r=0.320, P=0.0075) and a negative correlation between APACHE score and length of hospital stay in patients who died (r=-0.760, P=0.0225). Conclusions: The APACHE II scoring system may be usefully applied in emergency departments for predicting mortality, for classifying and assessing severity of disease, for evaluating performance and for planning departmental resource allocation. (Hong Kong j.emerg.med. 2002;9:188-194)