Using Literal Text From the Death Certificate to Enhance Mortality Statistics: Characterizing Drug Involvement in Deaths.

Objectives-This report describes the development and use of a method for analyzing the literal text from death certificates to enhance national mortality statistics on drug-involved deaths. Drug-involved deaths include drug overdose deaths as well as other deaths where, according to death certificate literal text, drugs were associated with or contributed to the death. Methods-The method uses final National Vital Statistics System-Mortality files linked to electronic files containing literal text information from death certificates. Software programs were designed to search the literal text from three fields of the death certificate (the cause of death from Part I, significant conditions contributing to the death from Part II, and a description of how the injury occurred from Box 43) to identify drug mentions as well as contextual information. The list of drug search terms was developed from existing drug classification systems as well as from manual review of the literal text. Literal text surrounding the identified drug search terms was analyzed to ascertain the context. Drugs mentioned in the death certificate literal text were assumed to be involved in the death unless contextual information suggested otherwise (e.g., "METHICILLIN RESISTANT STAPHYLOCOCCUS AUREUS INFECTION"). The literal text analysis method was assessed by comparing the results from application of the method with results based on ICD-10 codes, and by conducting a manual review of a sample of records.