The Accuracy of the ICD-10 Code for Trauma Patients Visiting on Emergency Department and the Error in the ICISS

Lee, Jae Hyuk; Sim, Min Seob

Abstract

PURPOSE
We designed a retrospective study to measure the accuracy of the ICD-10 (International Classification of Disease-10) code for trauma patients. We also analyzed the error of the ICISS (International Classification of Disease based Injury Severity Score) due to a missing or an incorrect ICD-10 code.
METHODS
For the measuring the accuracy of the ICD-10 code for trauma patients in a tertiary teaching hospital's emergency department, two board certified emergency physician performed a retrospective chart review. The ICD-10 code was classified as a main code or a sub-code. The main code was defined as the code of the main department of treatment, and the sub-code was defined as a code other than the main code. We calculated and compared two ICISS for each patient one by using both the existing code and the other by using a corrected code. We compared the proportions of severe trauma (defined as an ICISS less than 0.9) between when the existing code and the corrected code was used respectively.
RESULTS
We reviewed the records of 4287 trauma patients who had been treated from July 2008 to November 2008. The accuracy of the main code, the sub-code of emergency department, main-code, the subcode of hospitalized patients were 97.1%, 59.8%, 98.2% and 57.0%, respectively. Total accuracy of the main and sub-code of emergency department and of hospitalized patients were 91.4% and 58.6%. The number of severe trauma patients increased from 33 to 49 when the corrected code was used in emergency department and increased from 35 to 60 in hospitalized patients.
CONCLUSION
The accuracy of the sub-code was lower than that of the main code. A missing or incorrect subcode could cause an error in the ICISS and in the number of patients with severe trauma.