Association between undetermined intent death classification and county death investigation system for drug poisoning deaths in nine US jurisdictions

Background Both suicides and unintentional drug overdose deaths have risen dramatically over the last two decades in the USA. However, the classification of death manner intent can be a challenge for death investigators in drug poisoning deaths. This study assessed whether county death investigation system type was a predictive factor in the likelihood of ‘undetermined’ intent death classifications. Methods This study examines the association between undetermined intent classifications and death investigation systems among drug poisoning deaths in the USA. With novel data from the Centres for Disease Control and Prevention and from the State Unintentional Drug Overdose Reporting System in nine states, we used logistic regression models to analyse whether county coroner systems were differentially associated with ‘undetermined’ intent death classifications as compared with county medical examiner systems. Results County coroner systems were associated with increased odds of undetermined intent classifications in drug poisoning deaths as compared with county medical examiner systems (OR: 1.79; 95% CI 1.43 to 2.27). Even after a full set of county and individual decedent controls, the association remained (adjusted OR: 1.60; 95% CI 1.25 to 2.05). Conclusions Future work should examine ways to identify suicides in drug poisoning deaths, as the consequences of misclassification echo forward into data used for prevention. The type of death investigation system may be an important factor in how drug poisoning deaths are classified.