Combination of APACHE-II score and an obesity score (APACHE-O) for the prediction of severe acute pancreatitis

Background: The advent of specific therapeutic or preventive treatments for severe acute pancreatitis creates a need to determine the risk of complications for each individual. Scoring systems used in acute pancreatitis identify groups of patients at risk of complications, but the pancreatitis-specific scores require 48 h of hospital admission to give full information. The APACHE-II score is useful within 24 h, but ignores simple clinical features, such as obesity, known to predict severity. The aim of this study was to evaluate a combination of the APACHE-II score with an obesity score in patients with acute pancreatitis, to predict severity using information available during the first 24 h of hospital admission. Methods: Data were collected prospectively from 186 consecutive patients with acute pancreatitis, to allow calculation of the APACHE-II score and body mass index (BMI). BMI was categorised as normal (score = 0), overweight (BMI 26–30: score = 1), or obese (BMI > 30: score = 2). A logistic regression model was used to identify factors significantly associated with complications (Atlanta criteria; 104 complications in 60 patients). Results: Age, BMI and the acute physiology score independently predicted complications. Addition of the score for obesity to the APACHE-II score gave a composite score (APACHE-O) with greater predictive accuracy. At cut-off of > 8, APACHE-O had sensitivity 82%, specificity 86%, positive predictive value 74%, negative predictive value 91% and overall accuracy 85%. Conclusions: This study confirms that age, obesity and APACHE-II measured in the first 24 h of hospital admission can predict complications in acute pancreatitis. Combination of the APACHE-II and obesity scores by simple addition improved categorical prediction of severity (mild or severe) in patients with acute pancreatitis.