Awareness and access to naloxone necessary but not sufficient: Examining gaps in the naloxone cascade

Background: Despite promising findings of opioid overdose education and naloxone distribution (OEND) programs, overdose continues to be a major cause of mortality. The "cascade of care" is a tool for identifying steps involved in achieving optimal health outcomes. We applied the cascade concept to identify gaps in naloxone use. Methods: Data came from a cross-sectional survey of 353 individuals aged 18 and older who self-reported lifetime history of heroin use. Results: The sample was majority male (65%) and reported use of heroin (74%) and injection (57%) in the past 6 months. Ninety percent had ever witnessed an overdose and of these 59% were in the prior year. Awareness of naloxone (90%) was high. Of those aware, over two-thirds reported having ever received (e.g. access) (69%) or been trained to use naloxone (60%). Of those who had ever received naloxone (n = 218) over one-third reported possession never (36%) or rarely/sometimes carrying naloxone (38%), while 26% reported always carrying. Nearly half of those who had ever received naloxone reported ever use to reverse an opiate overdose (45%). Among individuals who had ever received naloxone, possession often/always compared to never was associated with being female (RRR = 2.88, 95%CI = 1.31-6.27) and ever used naloxone during an overdose (RRR = 4.68, 95%CI = 2.00-11.0). Conclusions: This study identifies that consistent possession is a gap in the naloxone cascade. Future research is needed to understand reasons for not always carrying naloxone.