Accuracy of International classification of diseases, 10th revision codes for identifying severe sepsis in patients admitted from the emergency department

To determine the accuracy of International classification of diseases, 10th revision, Australian modification (ICD-10-AM) codes in identifying severe sepsis in patients admitted from the emergency department (ED). A retrospective cohort study of ED patients transferred to the intensive care unit of a tertiary hospital within 24 hours of leaving ED, 2000- 2006. Clinical diagnosis of severe sepsis compared with diagnosis-based code (DB-C) categories based on ICD-10-AM codes in the Emergency Department Information Systems (EDIS) and Hospital Morbidity Data System (HMDS); sensitivity, specificity, positive predictive value (PPV) and negative predictive value of these databases. In the study period, 1645 patients were transferred to the ICU from the ED, of whom 254 had severe sepsis. Single discharge ICD-10-AM codes recorded in the EDIS and the principal ICD-10-AM codes recorded in the HMDS that fell into D-BC categories for sepsis, pneumonia, viscous perforation, peritonitis, cholecystitis or cholangitis had a PPV of 85.0% (95% CI, 78.4%-91.6%; 96/113) and 88.2% (95%CI, 72.6%-82.6%; 112/127), respectively. The respective sensitivity was 37.8% (95% CI, 31.8%-43.8%) (96/254) and 44.1% (95% CI, 38.0-50.2) (112/254). In contrast, ICD-10-AM codes in the HMDS that code for infection and organ dysfunction had a PPV of 33.5% (95% CI, 30.0%-37.0%; 227/677) and sensitivity of 89.4% (95% CI, 85.6%-93.2%; 227/254). ICD-10-AM codes recorded in the EDIS or HMD had limited utility for identifying severe sepsis in patients admitted to ICU from the ED.