Latent Classes of Drug Use among Current and Former People who Inject Drugs in Baltimore, MD, 2017
We interpreted item response probabilities for a 3-class model of drug use to characterize the predominant drug use typologies among participants in the ALIVE study during 2017. Most participants (76.3%) were assigned to an infrequent drug use class. All participants in the infrequent use class used ≤5 total substances and tended to use <once per day (Table 2). Nearly all participants in the heroin and/or cocaine injection class (11.8% of participants) injected heroin by itself (99.2%), cocaine by itself (97.1%), and speedball (heroin and cocaine at the same time, 96.5%). The remaining 11.9% of participants commonly used prescription drugs (93.7% used sedatives and/or tranquilizers and 91.3% used prescription opioids).