This study was conducted in two phases among independent samples of
illicit and licit opioid users. Phase 1 consisted of initial scale development
and Phase 2 consisted of scale confirmation. This study was approved by the
Johns Hopkins University and University of Vermont Institutional Review Boards
(IRBs) and waivers of informed consents were obtained for both sites.
Participants consisted of three subgroups of opioid users (total
N=848; Table 1) and
all data were collected between 12/2013 and 3/2015. All participants completed a
brief demographic and opioid overdose questionnaire to characterize the study
sample. The brief opioid overdose questionnaire asked whether the participant
had ever overdosed, had ever witnessed an overdose, or had ever been trained to
administer naloxone. To prevent biasing participant responses, overdose was not
operationalized for participants. Demographic and drug use characteristics from
the participants sampled in Phases 1 and 2 are presented in Table 1. The three samples differed in
several important ways, including race, likelihood of being married and
employed, and previous history of opioid overdose.