Concordance between controlled substance receipt and post-mortem toxicology in opioid-detected overdose deaths: A statewide analysis.

BACKGROUND

Opioid overdoses are a leading cause of preventable death in the United States. There is limited research linking decedents' receipt of controlled substances and presence of controlled substances on post-mortem toxicology (PMT).

METHODS

We linked data on opioid-detected deaths in Connecticut between May 3, 2016, and December 31, 2017 from the Office of the Chief Medical Examiner, Department of Consumer Protection, and Department of Mental Health and Addiction Services. Exposure was defined as receipt of an opioid or benzodiazepine prescription within 90 days prior to death. Our primary outcome was concordance between medication received and metabolites in PMT.

RESULTS

Our analysis included 1412 opioid-detected overdose deaths. 47 % received an opioid or benzodiazepine 90 days prior to death; 36 % received an opioid and 27 % received a benzodiazepine. Concordance between receipt of an opioid or benzodiazepine and its presence in PMT was observed in 30 % of opioid-detected deaths. Concordance with an opioid was present in 17 % of opioid-detected deaths and concordance with a benzodiazepine was present in 21 % of opioid-detected deaths. Receipt of an opioid or benzodiazepine and concordance with PMT were less common in fentanyl or heroin-detected deaths and more common in pharmaceutical opioid-detected deaths.

DISCUSSION: Our results suggest medically supplied opioids and benzodiazepines potentially contributed to a substantial number, though minority, of opioid-detected deaths during the study period. Efforts to reduce opioid and benzodiazepine prescribing may reduce risk of opioid-detected deaths in this group, but other approaches will be needed to address most opioid-detected deaths that involved non-pharmaceutical opioids.