In the United States, drug overdose mortality has increased. Death records categorize overdose deaths by type of drug involved, but do not include information about the route of drug administration.
We utilized data from drug treatment admissions (Treatment Episodes Dataset, TEDS-A) and National Vital Statistics Systems to estimate the percentage of reported drug overdose deaths that were injection-involved from 2000 to 2018 in the U.S. Data on reported route of administration at admission were used to calculate the percent injecting each drug type, by demographic group (race/ethnicity, sex, age group) and year. Using the resulting probabilities, we estimated the number of overdose deaths that were injection-involved. Estimates were compared across drug types, demographic characteristics, and year.
The number of overdose deaths among adults increased more than 3-fold from 2000 (n = 17,196) to 2018 (n = 67,021). During that timeframe, the number of estimated injection-involved overdose deaths increased more than 8-fold from 2000 (n = 3467, 95% CI: 3449–3485) to 2018 (n = 28,257, 95% CI: 28,192–28,322). From 2000–2007, the percent of overdose deaths that were injection-involved remained stable around 20%. From 2007–2018, the percent of overdose deaths that were injection-involved increased from 18.4% (95% CI: 18.3–18.6%) to 42.2% (95% CI: 42.1–42.3%). In 2018, most estimated injection-involved overdose deaths were due to injecting heroin/synthetic opioids (n = 24,860, 95% CI: 24,800–24,919), which accounted for 88.0% of all injection-involved deaths.
Much of the recent increase in overdose mortality is likely attributable to rising injection-involved overdose deaths.