Measuring Treatment Attrition at Various Stages of Engagement in Opioid Agonist Treatment in Ontario Canada Using a Cascade of Care Framework

Background The cascade of care framework is an effective way to measure attrition at various stages of engagement in Opioid Agonist Treatment (OAT). The primary objective of the study was to describe the cascade of care for individuals who have accessed OAT from a network of specialized addiction clinics in Ontario, Canada. The secondary objectives were to evaluate correlates associated with retention in OAT at various stages and the impact of patients' location of the residence on retention in OAT. Design: A multi-clinic retrospective cohort study was conducted using electronic medical record (EMR) data from the largest network of OAT clinics in Canada (70 clinics) from 2014-2020. Study participants included all individuals who received OAT from the network of clinics during the study period. Measurements: In this study, four stages of the cascade of care framework were operationalized to identify treatment engagement patterns, including patients retained within 90 days, 90 to 365 days, one to two years, and more than two years. Correlates associated with OAT retention for 90 days, 90 to 365 days, one to two years, and more than two years were also evaluated and compared across rural and urban areas in northern and southern Ontario. Results A total of 32,487 individuals were included in the study. Compared to individuals who were retained in OAT for 90 days, individuals who were retained for 90 to 365 days, one to two years, or more than two years were more likely to have a higher number of treatment attempts, a higher number of average monthly urine drug screening and a lower proportion of positive urine drug screening results for other drug use. Conclusion Distinct sociodemographic and clinical factors are likely to influence treatment retention at various stages of engagement along the OAT continuum. Research is required to determine if tailored strategies specific to people at different stages of engagement have the potential to improve outcomes of OAT.

Startle-elicited Event-Related Potentials to Affective Stimuli are Associated with Recent Illicit Opioid use among Patients Receiving Opioid Agonist Treatment

Opioid use disorder (OUD) has been linked to exaggerated attentional, affective, and arousal responses to opioid-related stimuli, as well as altered responses to other affective (eg, naturally rewarding or aversive) stimuli, particularly blunted responses to pleasant/rewarding stimuli. Both exaggerated responses to drug-related stimuli and reduced response to pleasant stimuli may influence the course of OUD and its treatment, however interpretation of studies thus far is limited by methodological issues. In the present study, we examined subjective ratings, and attenuation of the P3 component of the acoustic startle-evoked event-related potential (as a measure of attention), while viewing neutral, pleasant, unpleasant, and drug-related images. Participants prescribed opioid agonist treatment (OAT) for OUD (n = 82) were compared to a carefully-matched control group (n = 33) and to recently-abstinent participants with OUD (n = 22). Relative to controls, participants prescribed OAT gave higher positive valence ratings of drug images, and blunted valence responses to other affective images, but groups did not differ in terms of arousal ratings or P3 amplitude. Within the OAT group, linear modeling of associations between frequency of recent illicit opioid use and startle P3 amplitude found an association between increased recent illicit opioid use and reduced attention to pleasant, relative to unpleasant, images. The latter finding may have implications for interventions targeting cognitive biases in people with substance use disorder. In particular, they suggest that enhancing attention to pleasant stimuli may be as, if not more important, than the typical approach of trying to reduce attentional bias to drug-related stimuli.

Effectiveness and Safety of Low-Threshold Opioid-Agonist Treatment in Hard-To-Reach Populations with Opioid Dependence

<b><i>Objectives:</i></b> Opioid-use disorder is related to premature death worldwide. Opioid-agonist treatment (OAT) is an effective treatment for opioid dependence. OAT delivery platforms may influence treatment access and outcomes, especially for the most vulnerable groups. The aim of this study was to determine the effectiveness and safety of low-threshold OAT compared to the standard treatment. <b><i>Methods:</i></b> Patients with diagnosed opioid dependence undergoing low-threshold OAT at the Bergen delivery platform in Norway were enrolled in a cohort study in 2014–2019. A national OAT cohort was the reference group. The main outcomes were treatment retention, the use of illicit opioids, non-fatal overdose, overdose death, and all-cause mortality during the first year following treatment initiation and the full treatment period. Additionally, healthcare utilization in the periods before and during OAT was investigated. <b><i>Results:</i></b> Compared to the reference cohort, the low-threshold cohort (<i>n</i> = 128, mean age: 38 years, women: 28%) showed treatment retention rates of 95% versus 92%, illicit opioid use of 7% versus 10%, non-fatal overdose of 7% versus 6%, and death at 1.0% versus 1.3%, respectively. The incident rate ratios (IRRs) for healthcare utilization increased substantially during the OAT period compared to the period before; the IRR increased by 3.3 (95% confidence interval (CI): 2.8, 3.9) and 3.4 (95% CI: 3.1, 3.9) for all in- and outpatient healthcare, respectively. <b><i>Conclusions:</i></b> Low-threshold OAT was at least as effective and safe as the standard OAT in terms of treatment retention, the use of illicit opioids, non-fatal overdose, and death. Healthcare utilization increased during the OAT compared to the period before. Lowering the threshold for OAT entrance within proper delivery platforms should be broadly considered to reduce harm and improve healthcare access among patients with opioid dependence.