Citation

Carroll CP, Cochran JA, Guse CE, Wang MC. Neurosurgery 2012; 71(6): 1064-70; discussion 1070.

Affiliation

1Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI 2Injury Research Center, Department of Family & Community Medicine, Medical College of Wisconsin, Milwaukee, WI.

Copyright

(Copyright © 2012, Congress of Neurological Surgeons)

DOI

10.1227/NEU.0b013e31826f7c16

PMID

22922677

Abstract

BACKGROUND:: The epidemiology of traumatic brain injury (TBI) is often studied using International Classification of Disease, 9 Revision, Clinical Modification (ICD-9-CM) diagnosis codes from the Centers for Disease Control and Prevention (CDC) TBI Surveillance System. Recent studies suggest these codes may underestimate the burden of TBI due to inaccuracies and low sensitivity. OBJECTIVE:: To determine sensitivity/specificity of ICD-9-CM-codes in a severe TBI population. METHODS:: We retrospectively reviewed medical records of all hospital admissions undergoing computed tomography of the head at a single center to identify severe blunt TBI patients, their injuries, and neurosurgical procedures performed. We calculated sensitivity/specificity by comparing ICD-9-CM diagnosis and procedure codes assigned by hospital coders to medical records, the gold standard. RESULTS:: In 2008, there were 148 qualifying admissions. These codes were 89% sensitive for the presence of any severe TBI. However, 1/5 of these cases were only identified with a code defining a non-specific head injury. Next, we studied types of TBI by 1) categories defined by the CDC (Morbidity Groups) and 2) by ICD-9-CM-codes for types of injury (any skull fracture, intracranial contusion, intracranial hemorrhage, concussion/loss of consciousness), and found widely varying sensitivity/specificity for both. In general, these codes had higher specificity than sensitivity. Both sensitivity/specificity were >80% for only two categories: any skull fracture and intracranial hemorrhage. In contrast, we found high sensitivity/specificity for neurosurgical procedures (97%/94%). CONCLUSION:: ICD-9-CM-codes were sensitive for the presence of any severe TBI, but further classification of specific types of TBI was limited by variable sensitivity/specificity. Use of these codes should be supplemented by other methodology.

Language: en