Naloxone use among overdose prevention trainees in New York City: A longitudinal cohort study.

Background: Providing naloxone to laypersons who are likely to witness an opioid overdose is now a widespread public health response to the national opioid overdose epidemic. Estimating the proportion of individuals who use naloxone can define its potential impact to reduce overdose deaths at a population level. We determined the proportion of study participants who used naloxone within 12 months following training and factors associated with witnessing overdose and naloxone use.

Methods: We conducted a prospective, observational study of individuals completing overdose prevention training (OPT) between June and September 2013. Participants were recruited from New York City's six largest overdose prevention programs, all operated by syringe exchange programs. Questionnaires were administered at four time points over 12 months. Main outcomes were witnessing or experiencing overdose, and naloxone administration.

Results: Of 675 individuals completing OPT, 429 (64%) were approached and 351 (52%) were enrolled. Overall, 299 (85%) study participants completed at least one follow-up survey; 128 (36%) witnessed at least one overdose. Of 312 witnessed opioid overdoses, naloxone was administered in 241 events (77%); 188 (60%) by the OPT study participant. Eighty-six (25%) study participants administered naloxone at least once. Over one third of study participants (30, 35%) used naloxone 6 or more months after training.

Conclusions: Witnessing an overdose and naloxone use was common among this study cohort of OPT trainees. Training individuals at high risk for witnessing overdoses may reduce opioid overdose mortality at a population level if sufficient numbers of potential responders are equipped with naloxone.