Variations in drug specificity in US death certificate data for drug poisoning mortality surveillance, National Vital Statistics System, 2008-2009

There are over 2,000 death investigation jurisdictions in the US. Death investigations procedures and reporting for drug deaths may vary among these jurisdictions. This research uses the National Vital Statistics System multiple cause of death (NVSS-MCOD) data to examine the variation in the specificity of drugs involved in drug poisoning deaths by jurisdictional factors. Using 2008-2009 NVSS-MCOD files drug poisoning deaths were defined as having ICD-10 underlying cause of death: X40-X44, X60-X64, X85, Y10-Y14. Among drug poisoning deaths, deaths with only non-specified drug(s) involved were defined as those with T50.9 and no MCOD in the range T36-T50.8. The proportion of drug poisoning deaths in which the drug involved was not specified were calculated for factors related to jurisdiction, including state, centralized medical examiner, and urbanization. In the US, for 25% of drug poisoning deaths the drug(s) involved were not specified. In 5 states, the drug involved was not specified in over 50% of drug poisoning deaths. In the 15 states and District of Columbia with state-wide medical examiners, the drug was not specified in 9% of the deaths. For jurisdictions with state-wide ME, only 3 states had more than 10% of deaths with drug not specified. Large metropolitan areas had a lower percentage with unspecified drugs. Variations by state and other jurisdictional factors in reporting the specificity of drugs involved needs to be considered when presenting rates of drug poisoning deaths for specific drugs. Medical examiners and coroners should review and standardize their investigation and reporting methods.