Demographic and geographic shifts in the preferred route of methamphetamine administration among treatment cases in the US, 2010–2019

Abstract

BackgroundMethamphetamine use disorder has increased rapidly in the past decade. Injecting is also increasing and has multifaceted implications for disease severity, overall health, and treatment outcomes, but less is known about where or among whom injecting has shifted the most. This national study assessed temporal changes in the preferred route of methamphetamine administration by race/ethnicity and within urban/rural geographies. MethodsWe used the Treatment Episode Dataset-Discharges (2010–2019) to identify outpatient treatment cases who reported methamphetamine as their primary drug of choice at admission (N = 531,799; 2010 n = 33,744; 2019 n = 81,885). We created a combined variable indicating race/ethnicity and the rural/urban location of treatment, and used logistic regression to model the predicted probability of cases reporting injection, smoking, or snorting as their preferred route of administration. We included an interaction term to determine differences over time (race/ethnicity/rurality*year). ResultsAcross all years, smoking methamphetamine was the most common route of administration (66%), followed by injection (24%) and snorting (10%). Over time and among most sub-groups, the rates of injection increased while the rates of smoking decreased. Compared to 2010, the odds of injecting methamphetamine in 2019 were highest among Black cases in urban areas (aOR = 2.30, 95% CI = 1.76–3.00, p < 0.0001). ConclusionIncreasing methamphetamine injection was most pronounced among Black treatment cases in more urban areas, which is in contrast to the longstanding narrative that methamphetamine is a White and rural drug. Methamphetamine prevention, treatment, and harm reduction should target populations with high injection prevalence and growing incidence.