Development of a Coroner-Based Surveillance System for Drug-Related Deaths in Los Angeles County

Existing data sources do not provide comprehensive and timely information to adequately monitor drug-related mortality in Los Angeles County. To fill this gap, a surveillance system using coroner data was developed to examine patterns in drug-related deaths. The coroner provided data on all injury deaths in Los Angeles County. A list of keywords that indicate a death was caused by drug use was developed. The cause of death variables in the coroner data were searched for mentions of one of the keywords; if a keyword was detected, that death was classified as drug related. The effectiveness of the keyword list in classifying drug-related deaths was evaluated by matching records in the coroner death data to records in the state death files. Then, the drug-related deaths identified using the keywords were compared to drug-related deaths in the state mortality files identified using International Classification of Death codes. Toxicological test results were used to categorize drug-related deaths based on the type and legality of the drug(s) ingested. Mortality rates were calculated for each category of drug and legal status and for different demographic groups. Compared to the gold standard state mortality files, the coroner data had a sensitivity of 95.6% for identifying drug-related deaths. Over three quarters of all drug-related deaths tested positive for opiates and/or stimulants. Males, Whites, and 35–54-year-olds each accounted for more than half of all drug-related deaths. The surveillance of drug-related deaths using coroner data has several advantages: data are available in a timely fashion, the data include information about the specific substances each victim ingested, and the data can be broken down to compare mortality among specific subpopulations.