To the Editor.
—In 1989 we published a study that used death certificates for surveillance of head injury-associated deaths in the United States.1 A recent study on the use of death certificates for this purpose found that 99.6% of firearmrelated head injury deaths in New Mexico were assigned International Statistical Classification of Diseases, Ninth Revision (ICD-9) codes 870 through 873, codes that we had not used to define head injury in our study (written communication, David Nelson, MD, October 1991). We excluded from our study head injury codes that we believed were unlikely to include intracranial injury. The ICD-9 codes 870 through 873 are supposed to be used for open wounds of the head without intracranial injury2; however, these codes are, in fact, assigned to gunshot wounds to the head with intracranial injury. Rather than explore the process that leads to the inappropriate use of these
Sosin DM, Nelson DE, Sacks JJ. Head Injury Deaths: The Enormity of Firearms. JAMA. 1992;268(6):791. doi:10.1001/jama.1992.03490060127048