TRAUMA REGISTRY INJURY CODING IS SUPERFLUOUS - A COMPARISON OF OUTCOME PREDICTION BASED ON TRAUMA REGISTRY INTERNATIONAL CLASSIFICATION OF DISEASES 9TH REVISION (ICD-9) AND HOSPITAL INFORMATION-SYSTEM ICD-9 CODES

Background: Trauma registries are an essential but expensive tool for monitoring trauma system performance, The time required to catalog pat ients' injuries is the source of much of this expense, Typically, 15 m inutes of chart review per patient are required, which in a busy traum a center may represent 25% of a full-time employee, We hypothesized th at International Classification of Disease-Ninth Revision (ICD-9) code s generated by the hospital information system (HI) would be similar t o those coded by a dedicated trauma registrar (TR) and would be as acc urate as TR ICD-9 codes in predicting outcome. Methods: One thousand e ight hundred twelve patients admitted to a Level I trauma center durin g 2 years had International Classification of Disease Injury Severity Scores (ICISS) calculated based on HI and TR ICD-9 codes, The relative predictive powers of these two ICISSs were then compared for every pa tient using Receiver Operator Characteristic Curve Area (ROC) and Hosm er Lemeshow Statistics. Results: Eighty-nine percent of patients (1,60 8 of 1,812) had identical HI and TR ICISSs, Eleven patients' ICISSs di ffered by >0.1, and only two patients' scores differed by >0.2, ICISS proved to be a powerful predictor of outcome whether derived from HI ( ROC = 0.884; 95% confidence interval (CI) = 0.850 - 0.917) or TR (ROC = 0.872; 95% CI = 0.837 - 0.908), Although these predictive powers wer e not significantly different (p = 0.076), the trend was for HI to per form better than TR, ISS calculated for the same data set using the Ma cKenzie dictionary proved significantly less predictive of outcome tha n either ICISS (ROCMacKenzie = 0.843; 95% CI = 0.792 - 0.884; p = 0.03 4). Conclusion: We conclude that in our hospital TR data on individual injuries can be replaced by HI data without loss of predictive power, ISS based on the MacKenzie dictionary should be abandoned because it is much less predictive of outcome than ICISS.