Non-medical prescription opioid use, prescription opioid-related harms and public health in Canada: an update 5 years later

Sensitivity to change of generic preference-based instruments (EQ-5D-3L, EQ-5D-5L, and HUI3) in the context of treatment for people with prescription-type opioid use disorder in Canada

PURPOSE

Using data from a randomized controlled trial for treatment of prescription-type opioid use disorder in Canada, this study examines sensitivity to change in three preference-based instruments [EQ-5D-3L, EQ-5D-5L, and the Health Utilities Index Mark 3 (HUI3)] and explores an oft-overlooked consideration when working with contemporaneous responses for similar questions-data quality.

METHODS

Analyses focused on the relative abilities of three instruments to capture change in health status. Distributional methods were used to categorize individuals as 'improved' or 'not improved' for eight anchors (seven clinical, one generic). Sensitivity to change was assessed using area under the ROC (receiver operating characteristics) curve (AUC) analysis and comparisons of mean change scores for three time periods. A 'strict' data quality criteria, defined a priori, was applied. Analyses were replicated using 'soft' and 'no' criteria.

RESULTS

Data from 160 individuals were used in the analysis; 30% had at least one data quality violation at baseline. Despite mean index scores being significantly lower for the HUI3 compared with EQ-5D instruments at each time point, the magnitudes of change scores were similar. No instrument demonstrated superior sensitivity to change. While six of the 10 highest AUC estimates were for the HUI3, 'moderate' classifications of discriminative ability were identified in 12 (of 22) analyses for each EQ-5D instrument, compared with eight for the HUI3.

CONCLUSION

Negligible differences were observed between the EQ-5D-3L, EQ-5D-5L, and HUI3 regarding the ability to measure change. The prevalence of data quality violations-which differed by ethnicity-requires further investigation.

Flexible Buprenorphine/Naloxone Model of Care for Reducing Opioid Use in Individuals With Prescription-Type Opioid Use Disorder: An Open-Label, Pragmatic, Noninferiority Randomized Controlled Trial

OBJECTIVE

Extensive exposure to prescription-type opioids has resulted in major harm worldwide, calling for better-adapted approaches to opioid agonist therapy. The authors aimed to determine whether flexible take-home buprenorphine/naloxone is as effective as supervised methadone in reducing opioid use in prescription-type opioid consumers with opioid use disorder.

METHODS

This seven-site, pan-Canadian, 24-week, pragmatic, open-label, noninferiority, two-arm parallel randomized controlled trial involved treatment-seeking adults with prescription-type opioid use disorder. Participants were randomized in a 1:1 ratio to treatment with sublingual buprenorphine/naloxone (target dosage, 8 mg/2 mg to 24 mg/6 mg per day; flexible take-home dosing) or oral methadone (≈60-120 mg/day; closely supervised). The primary outcome was the proportion of opioid-free urine drug screens over 24 weeks (noninferiority margin, 15%). All randomized participants were analyzed, excluding one who died shortly after randomization, for the primary analysis (modified intention-to-treat analysis).

RESULTS

Of 272 participants recruited (mean age, 39 years [SD=11]; 34.2% female), 138 were randomized to buprenorphine/naloxone and 134 to methadone. The mean proportion of opioid-free urine drug screens was 24.0% (SD=34.4) in the buprenorphine/naloxone group and 18.5% (SD=30.5) in the methadone group, with a 5.6% adjusted mean difference (95% CI=-0.3, +∞). Participants in the buprenorphine/naloxone group had 0.47 times the odds (95% CI=0.24, 0.90) of being retained in the assigned treatment compared with those in the methadone group. Overall, 24 drug-related adverse events were reported (12 in the buprenorphine/naloxone group [N=8/138; 5.7%] and 12 in the methadone group [N=12/134; 9.0%]) and mostly included withdrawal, hypogonadism, and overdose.

CONCLUSIONS

The buprenorphine/naloxone flexible model of care was safe and noninferior to methadone in reducing opioid use among people with prescription-type opioid use disorder. This flexibility could help expand access to opioid agonist therapy and reduce harms in the context of the opioid overdose crisis.

Trends in opioid analgesic utilisation among people with a history of opioid dependence

BACKGROUND

We aimed to characterise opioid analgesic utilisation over a 16-year period among a cohort of people with a history of opioid dependence, comparing rates of use in and out of opioid agonist treatment (OAT).

METHODS

Retrospective cohort study in New South Wales, Australia, including 28,891 people with documented opioid dependence initiating opioid analgesics between July 2003 and December 2018. Linked administrative records provided data on prescription dispensings, sociodemographics, clinical characteristics, and OAT. Generalised estimating equation models estimated the incidence and adjusted incidence rate ratios (IRR) comparing periods in and out of OAT for the number of opioid analgesic dispensings (overall, for strong opioids, and the most commonly dispensed opioid types) and the amount dispensed in oral morphine equivalent milligrams (OME).

RESULTS

At initiation, 43.7% of the cohort were enrolled in OAT. The most commonly initiated opioid was codeine (including combinations with paracetamol; 67.8%), and 49.6% of the cohort were dispensed a psychotropic medicine in the previous 90 days. Incidence of all opioid analgesic dispensings was higher during periods out of OAT compared to in OAT (5.8 v. 2.3 dispensings per person-year; IRR 0.39, 95% CI 0.38, 0.41), with findings similar when stratified by type. Being in OAT was associated with a lower OME amount dispensed compared to out of OAT (-57.7%, 95% CI-58.8, -56.7).

CONCLUSIONS

People with opioid dependence had high rates of recent psychotropic medicine utilisation and current OAT enrolment at the time of opioid analgesic initiation. OAT was associated with a significant reduction in opioid analgesic dispensing.

Increasing trend in accidental pharmaceutical opioid overdose deaths and diverging overdose death correlates following the opioid prescription policy liberalization in Norway 2010-2018

BACKGROUND

During the last decade, opioid prescription policies in Norway have been liberalised and pharmaceutical opioid (PO) dispensing has increased. Against this backdrop, we examined the trends in and the correlates of accidental overdose deaths attributable to PO in the period 2010-2018 in comparison with traditional heroin overdose deaths.

METHODS

Accidental overdose deaths attributable to PO or heroin were identified through the Norwegian Cause of Death Registry (n = 1267) and cross-linked with population and patient registries. Overdose death correlates were examined using multivariable logistic regression.

FINDINGS

The trend in accidental overdose deaths attributable to PO increased significantly from 2010 to 2018. Females, people aged 50 years or older, disability pension recipients and/or those with the highest net wealth had a greater risk of a PO vs. heroin overdose death, while those dying in public spaces, living in urban areas, having recent specialized drug treatment encounters, and/or criminal charge(s) had a lower risk. Among those with primary health care encounters, those with back problems and accidents and injuries had a greater risk of a PO vs. heroin overdose death, while those with a substance use disorder had a lower risk.

CONCLUSION

The increase in accidental overdose deaths attributable to PO coincides with the period of opioid prescription policy liberalization and an increase in PO consumption in Norway. The PO and heroin overdose deaths differed in terms of the associated sociodemographic characteristics, primary and secondary health care encounters, diagnoses, and criminal charges, indicating a need for additional interventions aimed at preventing PO overdose deaths specifically.

Dealing with the epidemic of endocarditis in people who inject drugs

North America is facing an opioid epidemic and growing illicit drug supply, contributing to growing numbers of injection drug use-related infective endocarditis (IDU-IE). Patients with IDU-IE have high early and late mortality. Patients with IDU-IE more commonly present with right-sided IE compared to those with non-IDU-IE and a majority are a result of S. aureus. While most patients can be successfully managed with intravenous antibiotic treatment, surgery is often required in part related to high relapse rates, potential treatment biases, and more aggressive pathophysiology in some. Multidisciplinary management as endocarditis teams, including not only cardiologists and cardiac surgeons but also infectious disease specialists, drug addiction experts, social workers, neurologists and/or neurosurgeons, is essential to best manage substance use disorder and facilitate safe discharge to home and society. Structural and population-level interventions, such as harm reduction programs, are necessary to reduce IDU-IE relapse rates in the community and other IDU-related health concerns such as overdoses. In this review, we describe the pathophysiological, clinical, surgical, social, and ethical characteristics of IDU-IE and the management thereof. We present the most recent clinical guidelines for this condition and discuss existing gaps in knowledge to guide future research, practice changes, and policy interventions.

Trends in dispensing of individual prescription opioid formulations, Canada 2005-2020

Background

Canada has experienced a distinctly bifurcated pattern of (strong) opioid utilization post-2000, with multifold increases rendering it one of the world’s highest opioid consumption rates, followed by subsequent substantive declines since 2011/2012. Several interventions to control especially high-risk opioid use have been implemented post-2010 at different levels, yet with their effects assessed mostly for overall opioid utilization. Little knowledge exists for over-time patterns of individual opioid formulations.

Methods

Raw information on community-based prescription opioid dispensing for years 2005–2020 were obtained from a large national database based on a stratified sample of 6500 retail pharmacies across Canada (IQVIA/Compuscript), These data were converted into Defined-Daily-Doses/1000 population/day (DDD/1000/day) for individual (strong and weak) opioid formulations—specifically: fentanyl, hydromorphone, hydrocodone, morphine, oxycodone, codeine—per standard methods. Descriptive data on individual opioid dispensing were computed, and segmented regression (or ‘broken-stick’) analysis was applied to the overtime dispensing towards assessing potentially significant ‘breakpoints’ interrupting linear utilization trends. Akaike information criterion (AIC) values were computed to assess the resulting models’ quality-of-fit.

Results

Five of the six opioid formulations featured a lower dispensing level in 2020 compared with 2005, but mostly with peak values in years between, contributing to the overall inversion pattern. For five of the six opioid formulations, a three-segmented model emerged as the best fit for the dispensing observed; only hydrocodone presented a linear (downward) dispensing trend. Among the five interrupted trend models for individual formulations, four (fentanyl, morphine, oxycodone, codeine but not hydromorphone) indicated their initial breakpoint during 2011–2014 introducing a downward dispensing trend. Inconsistently, morphine also featured a recent breakpoint (2018) towards a dispensing increase.

Conclusions

While all opioids showed marked declines, we found heterogeneous patterns of dispensing for individual opioid formulations. While we cannot estimate direct causal effects, opioid control interventions appear to have had differential impacts on dispensing of individual formulations. The earliest breakpoint occurred towards substantive decreases for oxycodone dispensing in 2011; subsequently, there were increases in dispensing of hydromorphone and fentanyl likely due to substitution effects, followed by across-the-board declines post-2015/2016. Recent ‘safer opioid’ distribution programs to reduce illicit/toxic opioid exposure linked with high levels of poisoning fatalities seem to fuel resurgences in select opioid (e.g., morphine) dispensing.

Patterns of prescription opioid dispensing among Red River Métis in Manitoba, Canada: a retrospective longitudinal cross-sectional study

BACKGROUND

Amid rising concern about opioid use across Canada, Métis leaders in Manitoba are seeking information on prescription opioid dispensing in Red River Métis populations to assist with planning and implementing appropriate evidence-based harm-reduction strategies in their communities. We examined patterns of prescription opioid dispensing among Red River Métis and compared them to those among other residents of Manitoba.

METHODS

We conducted a population-based retrospective cross-sectional study for fiscal years 2006/07-2018/19 using administrative data from the Manitoba Population Research Data Repository and a study designed in partnership with researchers from the Manitoba Métis Federation. We compared age- and sex-adjusted rates of prescription opioid dispensing and mean morphine equivalents (MEQ) between Red River Métis and all other Manitobans aged 10 years or older, in accordance with Indigenous data sovereignty principles. To better understand what was driving any differences in patterns of prescription opioid dispensing between the 2 groups, we stratified the groups by age, sex, urbanicity, number of comorbidities, income quintile and opioid type, and compared patterns in MEQ/person.

RESULTS

The 2018/19 cohort included 76 755 Red River Métis and 1 117 854 other Manitobans. Other Manitobans were more likely than Red River Métis to be in higher income quintiles and to live in urban areas, and were less likely to have been diagnosed with a mood or anxiety disorder or a substance use disorder in the previous 5 years. The rate of prescription opioid dispensing and the opioid-associated MEQ/person were consistently higher among Red River Métis than among other Manitobans in each study year (p < 0.001). The rate of prescription opioid dispensing declined and the MEQ/person rose among other Manitobans over the study period but did not change among Red River Métis.

INTERPRETATION

The rate of prescription opioid dispensing and the potency of prescribed opioids were higher among Red River Métis in Manitoba than among other Manitobans. Further investigation into the different dispensing patterns between the 2 groups and the potential opioid-related harms they may herald is warranted.

Patient perspectives from the multi-disciplinary chronic pain clinic: a qualitative study

Aim: The chronic pain clinic (CPC) is a multi-disciplinary program that incorporates pharmacological and non-pharmacological methods, including First Nations healing strategies, to manage pain, improve functioning and reduce opioid misuse among patients with chronic pain in Regina, Canada. Materials & methods: The care experiences of ten current clients were explored using a narrative interview approach. Results: The CPC provides high-quality and safe care for effective chronic pain management. Clients noted pain reduction and improvements in sleep, mobility, functionality, and mood. First Nation clients emphasized the importance of traditional healing strategies. Conclusion: This unique comprehensive multi-modal approach which incorporates First Nations healing strategies is effective in supporting the unique needs of local clients.

Evaluation of Opioid Prescribing Patterns and Use Following Hysterectomy for Benign Indication: A Prospective Cohort Study

OBJECTIVES

To evaluate surgeon opioid prescribing patterns for patients undergoing hysterectomy for benign indication, as well as patient use of postoperative medications and satisfaction with postoperative pain management.

METHODS

Patients undergoing hysterectomy for benign indications at Kingston Health Sciences Centre were invited to participate in a telephone survey 2 weeks post-surgery to review their analgesia use and pain management. Patient demographics, medical history, intraoperative surgical details, and postoperative prescriptions were gathered through patient record review. Opioid prescribing and utilization patterns were assessed, as was satisfaction with postoperative pain management.

RESULTS

Of 124 eligible patients 110 (89%) completed the telephone survey, a mean 15.9 ± 2.3 days after surgery. The mean age of participants was 51.6 ± 11.9 years. Most surgeries (84.5%) were minimally invasive, and 45.5% of patients were discharged within 24 hours of surgery. An opioid prescription was given to 71.8% of participants, and 52.7% used at least 1 dose of opioid medication after discharge. Most participants described very good or adequate postoperative pain management (88.2%). Satisfaction with postoperative pain control was not associated with receipt of an opioid prescription (P = 0.89). A greater proportion of those who used 1 or more doses of opioids versus none indicated poor or inadequate pain management (19.0% vs. 4.1%; P = 0.035).

CONCLUSION

Many patients do not use postoperative opioid analgesia following hospital discharge after hysterectomy, without experiencing poor pain management. Surgeons should assess each individual and tailor the analgesia plan as necessary, optimizing non-opioid options.

Patterns, trends and determinants of medical opioid utilization in Canada 2005-2020: characterizing an era of intensive rise and fall

BACKGROUND

Into the 21st century, the conflation of high rates of chronic pain, systemic gaps in treatment availability and access, and the arrival of potent new opioid medications (e.g., slow-release oxycodone) facilitated strong increases in medical opioid dispensing in Canada. These persisted until post-2010 alongside rising opioid-related adverse (e.g., morbidity/mortality) outcomes. We examine patterns, trends and determinants of opioid dispensing in Canada, and specifically its 10 provinces, for the years 2005-2020.

METHODS

Raw data on prescription opioid dispensing were obtained from a large national community-based pharmacy database (IQVIA/Compuscript), converted into Defined-Daily-Doses/1,000 population/day for 'strong' and 'weak' opioid categories per standard methods. Dispensing by opioid category and formulations by province/year was assessed descriptively; regression analysis was applied to examine possible segmentation of over-time strong opioid dispensing.

RESULTS

All provinces reported starkly increasing strong opioid dispensing peaking 2011-2016, and subsequent marked declines. About half reported lower strong opioid dispensing in 2020 compared to 2005, with continuous inter-provincial differences of > 100 %; weak opioids also declined post-2011/12. Segmented regression suggests breakpoints for strong opioids in 2011/12 and 2015/16, coinciding with main interventions (e.g., selective opioid delisting, new prescribing guidelines) towards more restrictive opioid utilization control.

CONCLUSIONS

We characterized an era of marked rise and fall, while featuring stark inter-provincial heterogeneity in opioid dispensing in Canada. While little evidence for improvements in pain care outcomes exists, the starkly inverting opioid utilization have been associated with extensive population-level harms (e.g., misuse, morbidity, mortality) over-time. This national case study raises fundamental questions for opioid-related health policy and practice.

Association of Opioid Consumption Profiles After Hospitalization With Risk of Adverse Health Care Events

IMPORTANCE

Although better pain management has guided policies for opioid use over the past few decades, evidence is limited regarding how patterns of use are associated with the risk of potentially avoidable opioid-related adverse events.

OBJECTIVE

To estimate the risk of harms associated with opioid dose and duration of use, and to ascertain whether the risk is modified by treatment indication and age.

DESIGN, SETTING, AND PARTICIPANTS

This ad hoc cohort study followed up patients who were enrolled in a cluster randomized trial of medication reconciliation between October 1, 2014, and November 30, 2016, 12 months after they were discharged from the McGill University Health Centre in Montreal, Quebec, Canada. To be eligible for this study, patients needed to have filled at least 1 opioid prescription 3 months after discharge. Patients with a history of using methadone or buprenorphine were excluded. Data analyses were performed between February 1, 2019, and February 28, 2020.

EXPOSURES

Time-varying measures of opioid use included current use, daily morphine milligram equivalent (MME) dose, cumulative and continuous use duration, and type of ingredients in prescription opioids used. Hospitalization records, dispensed prescriptions records, and postdischarge interviews were used to evaluate adherence to the opioid prescriptions after discharge.

MAIN OUTCOMES AND MEASURES

Opioid-related emergency department visits, hospital readmissions, or all-cause death. Outcomes were ascertained using provincial medical services claims and hospitalization databases.

RESULTS

Of 3486 participants in the cluster randomized trial (mean [SD] age of 69.6 [14.9] years; 2010 men [57.7%]), 1511 patients were included in this ad hoc cohort study. Among those with at least 1 opioid dispensation, 241 patients (15.9%) experienced an opioid-related emergency department visit, hospital readmission, or death. Results from marginal structural Cox proportional hazards regression models showed more than a 2-fold increase in the risk of opioid-related adverse events associated with a cumulative use duration of more than 90 days (adjusted hazard ratio, 2.56; 95% CI, 1.25-5.27) compared with 1 to 30 days. A 3-fold risk increase was found with a mean daily dose higher than 90 MME (adjusted hazard ratio, 3.51; 95% CI, 1.58-7.82) compared with 90 MME or lower.

CONCLUSIONS AND RELEVANCE

This study found an association between risk of adverse health care events and higher opioid doses and longer treatment duration. This finding can inform policies for limiting opioid duration and dose to attenuate the risk of avoidable morbidity.

Overdose Risk and Acquiring Opioids for Nonmedical Use Exclusively from Physicians in Vancouver, Canada

BACKGROUND

A primary response to the alarming rise in overdose and mortality due to nonmedical prescription opioid (PO) use has been to restrict opioid prescribing; however, little is known about the relationship between obtaining opioids from a physician and overdose risk among people who use POs nonmedically and illicit street drugs. Objectives: Investigate the relationship between non-fatal overdose and acquiring POs exclusively from physicians for the purposes of engaging in nonmedical PO use. Methods: Data were collected between 2013 and 2016 among participants in two harmonized prospective cohort studies of people who use drugs in Vancouver: the At-Risk Youth Study (ARYS) and the Vancouver Injection Drug Users Study (VIDUS). Analyses were restricted to participants who engaged in nonmedical PO use and used generalized estimating equations. Results: Among 599 participants who used POs nonmedically, 82 (14%) individuals reported acquiring POs exclusively from a physician and 197 (33%) experienced a non-fatal overdose at some point over the study period. Acquiring POs exclusively from physicians was significantly and negatively associated with non-fatal overdose in the bivariate analysis (Odds Ratio = 0.60, 95% Confidence Interval (CI): 0.39-0.94) but not the final multivariate analysis (Adjusted Odds Ratio =0.87, 95% CI: 0.53-1.44). Conclusions: Compared to individuals who acquired POs from friends or the streets, participants who acquired POs exclusively from a physician were not at an increased risk of non-fatal overdose. Although responsible opioid prescribing is an important priority, additional strategies to address nonmedical PO use are urgently needed to reduce overdose and related morbidity and mortality.

Framework for improving outcome prediction for acute to chronic low back pain transitions

Clinical practice guidelines and the Federal Pain Research Strategy (United States) have recently highlighted research priorities to lessen the public health impact of low back pain (LBP). It may be necessary to improve existing predictive approaches to meet these research priorities for the transition from acute to chronic LBP. In this article, we first present a mapping review of previous studies investigating this transition and, from the characterization of the mapping review, present a predictive framework that accounts for limitations in the identified studies. Potential advantages of implementing this predictive framework are further considered. These advantages include (1) leveraging routinely collected health care data to improve prediction of the development of chronic LBP and (2) facilitating use of advanced analytical approaches that may improve prediction accuracy. Furthermore, successful implementation of this predictive framework in the electronic health record would allow for widespread testing of accuracy resulting in validated clinical decision aids for predicting chronic LBP development.

The Surgeon's Role in the Opioid Crisis: A Narrative Review and Call to Action

Over the past two decades, there has been a sharp rise in the use of prescription opioids. In several countries, most notably the United States, opioid-related harm has been deemed a public health crisis. As surgeons are among the most prolific prescribers of opioids, growing attention is now being paid to the role that opioids play in surgical care. While opioids may sometimes be necessary to provide patients with adequate relief from acute pain after major surgery, the impact of opioids on the quality and safety of surgical care calls for greater scrutiny. This narrative review summarizes the available evidence on rates of persistent postsurgical opioid use and highlights the need to target known risk factors for persistent postoperative use before patients present for surgery. We draw attention to the mounting evidence that preoperative opioid exposure places patients at risk of persistent postoperative use, while also contributing to an increased risk of several other adverse clinical outcomes. By discussing the prevalence of excess opioid prescribing following surgery and highlighting significant variations in prescribing practices between countries, we note that there is a pressing need to optimize postoperative prescribing practices. Guided by the available evidence, we call for specific actions to be taken to address important research gaps and alleviate the harms associated with opioid use among surgical patients.

The opioid mortality epidemic in North America: do we understand the supply side dynamics of this unprecedented crisis?

While there has been extensive attention to the 'demand side' - or use and adverse consequences, including mortality - of the 'opioid crisis' presently unfolding across North America, few considerations have focused on the supply side. This paper examines the supply side dynamics of this unprecedented public health phenomenon. We provide evidence for several interrelated supply-side elements that have contributed to the present public health crisis. We observe that initially, persistently high levels of prescription opioid availability and use exposed large proportions of the North American population to opioids, resulting in correspondingly high levels of medical and non-medical use (e.g., involving diversion). While various intervention measures to control prescription opioid availability and use have been implemented in recent years, leading to eventual reductions in opioid dispensing levels, these occurred late in the crisis's evolution. Moreover, these supply reductions have not been met by corresponding reductions in opioid use or demand levels. These growing discrepancies between opioid demand and prescription-based sources have left major gaps in opioid supplies. In response to such supply gaps, highly potent and toxic illicit opioid products have rapidly proliferated across North America, and become a core driver of the dramatic spikes in opioid overdose fatality levels in recent years. These supply-related interrelations are corroborated by a corresponding increase in illicit opioid-related fatalities, which arose just as medical opioid supplies began to decrease in many jurisdictions. Improved analyses and understanding of the supply-side dynamics of the opioid crisis are urgently needed in order to inform future intervention and policy development. Meanwhile, the high mortality toll related to illicit, highly toxic opioid exposure requires sustained solutions, including supply-oriented measures (e.g., safer opioid distribution for at-risk users) towards improved public health protection.

A decade of extreme oscillations in opioid control and availability: implications for public health in a Canadian setting

We comment on developments in and impacts of medical opioid control and availability in the province of British Columbia (Canada). Population-level dispensing of (strong) prescription opioids doubled in 2005-2011, yet subsequently declined by half 2011-2018 following implementation of various opioid control measures. Notwithstanding this inversion, BC has featured the highest population rates of opioid-related mortality and morbidity in Canada. The erratic opioid availability patterns presumably facilitated major increases in opioid misuse, morbidity, and mortality. Tangible benefits for pain care from increased medical opioid availability remain un-evidenced. Rather, recent decreases in medical opioid dispensing have not been matched by equivalent reductions in demand for (non-)medical use yet have coincided with widespread proliferation of toxic, illicit opioid supply and related major increases in opioid-related mortality. These developments appear to have undermined rather than benefitted public health and offer a poignant case study in ineffective psychotropic drug control and public health policy towards preventing similar experiences elsewhere.

The risk of infective endocarditis among people who inject drugs: a retrospective, population-based time series analysis

BACKGROUND

Infective endocarditis is an increasingly common complication among people who inject drugs. We conducted this study to determine whether the removal of traditional controlled-release oxycodone from the Canadian market would be associated with an increase in the use of hydromorphone and an increased risk of infective endocarditis.

METHODS

We conducted a retrospective, population-based time series analysis using the linked health administrative databases of Ontario, Canada. We measured the quarterly risk of admissions for infective endocarditis related to injection drug use and changes in opioid prescription rates from 2006 to 2015. We set the intervention point at the fourth quarter of 2011, when traditional controlled-release oxycodone was removed from the Canadian market.

RESULTS

We observed an increase in the risk of admissions for infective endocarditis related to injection drug use during the study period. Before the intervention point, we observed a mean of 13.4 admissions per quarter, and after the intervention, we observed a mean of 35.1 admissions per quarter. However, no significant change in this risk occurred at the intervention point. Rather, the risk of infectious endocarditis appeared to have increased earlier and in parallel with the rise in hydromorphone prescriptions. Hydromorphone represented 16% of all opioid prescriptions at the start of the observation period and 53% by the end.

INTERPRETATION

The risk of infective endocarditis related to injection drug use is increasing and is temporally associated with increasing prescriptions for hydromorphone. This relation warrants further exploration.

A gender-based analysis of nonmedical prescription opioid use among people who use illicit drugs

BACKGROUND

Research investigating the unique impacts associated with engaging in nonmedical prescription opioid use (NMPOU) among males and females who also use illicit drugs is needed.

METHODS

Data were collected between 2013 and 2017 from two linked prospective cohort studies in Vancouver: the At-Risk Youth Study and Vancouver Injection Drug Users Study. Generalized estimating equations were used to identify factors associated with engaging in NMPOU among females and males separately.

RESULTS

Among 1459 participants, 534 were female (37%). Similar proportions of females (46%) and males (48%) engaged in NMPOU at their first visit during the study period. In multivariable analyses, factors associated with NMPOU among both males and females included heroin use, overdose, drug dealing, and difficulty accessing health and social services. Among females, those who engaged in NMPOU were more likely to report Caucasian or white ethnicity, cocaine use, crystal methamphetamine use, and sex work; among males, those who engaged in NMPOU were older, reported crack use and engaged in binge drug use (all p < 0.05).

CONCLUSION

The prevalence of NMPOU was similar among males and females who use illicit drugs in Vancouver, and NMPOU was independently associated with markers of vulnerability among both genders. Findings highlight the need for a comprehensive public health approach to address NMPOU that integrates overdose prevention and reversal services, employment opportunities, and better access to services for both women and men.

Inappropriate opioid prescribing practices: A narrative review

Purpose

Results of a literature review to identify indicators of inappropriate opioid prescribing are presented.

Summary

While prescription opioids can be effective for the treatment of acute pain, inappropriate prescribing practices can increase the risk of opioid-related harms, including overdose and mortality. To date, little research has been conducted to determine how best to define inappropriate opioid prescribing. Five electronic databases were searched to identify studies (published from database inception to January 2017) that defined inappropriate opioid prescribing practices. Search terms varied slightly across databases but included opioid, analgesics, inappropriate prescribing, practice patterns, and prescription drug misuse. Gray literature and references of published literature reviews were manually searched to identify additional relevant articles. From among the 4,665 identified articles, 41 studies were selected for data extraction and analysis. Fourteen studies identified high-daily-dose opioid prescriptions, 14 studies identified coadministration of benzodiazepines and opioids, 10 studies identified inappropriate opioid prescribing in geriatric populations, 8 studies identified other patient-specific factors, 4 studies identified opioid prescribing for the wrong indication, and 4 studies identified factors such as initiation of long-acting opioids in opioid-naive patients as indicators of inappropriate opioid prescribing.

Conclusion

A literature review identified various indicators of inappropriate opioid prescribing, including the prescribing of high daily doses of opioids, concurrent benzodiazepine administration, and geriatric-related indicators. Given the significant contribution of inappropriate opioid prescribing to opioid-related harms, identification of these criteria is important to inform and improve opioid prescribing practices among healthcare providers.

Chronic pain management among people who use drugs: A health policy challenge in the context of the opioid crisis

BACKGROUND

In Canada, the rise in prescription opioid (PO) overdoses and addiction is a major public health concern. Various health authorities have recently recommended that physicians use caution when prescribing opioids, especially to people with histories of substance use. As a result, fewer therapeutic options are available for people who use drugs (PWUD) and suffer from chronic non-cancer pain (CNCP). This paper examines how PWUD describe their experiences with CNCP management in the context of the opioid crisis.

METHODS

This qualitative study is based on in-depth interviews with Montreal (Canada) PWUD experiencing CNCP for 3 months or more.

RESULTS

Most of the 25 participants (27-61 years; 10 women, 15 men) were polysubstance users (cocaine, opioids, amphetamine, etc.) suffering from CNCP for several years, with multiple additional health and social problems. The majority were unsatisfied with their CNCP management. They felt labelled as "addicts" and stigmatized within the healthcare system. Many participants had been denied PO, even those with severe CNCP and those who were not opioid-dependent. Participants expressed a desire to access non-pharmacological CNCP therapies, but these were often too expensive. Some PWUD were offered methadone to relieve CNCP and found this inappropriate. As a last resort several participants reported self-medicating CNCP with street drugs, increasingly known to be laced with fentanyl.

CONCLUSION

PWUD with CNCP are affected by two opioid crises: the PO crisis and the street-opioid crisis. The lack of a coherent policy that addresses their pain management produces reoccurring problems when seeking CNCP relief. Restrictive prescription measures implemented in response to the PO crisis may have consequences similar to prohibitionist policies: they heighten overdose risks for PWUD by increasing exposure to street drugs laced with fentanyl. Improving access to diverse CNCP management options for PWUD can help reduce harms related to street-opioid use.

Opioid prescribing and dispensing: Experiences and perspectives from a survey of community pharmacists practising in the province of Quebec

Background

Canada leads in opioid prescription and consumption rates, and this has resulted in high levels of opioid-related morbidity and mortality. Pharmacists' input could contribute significantly to understanding the disadvantages of opioid prescribing and dispensing and improving the service. This study aimed to examine the experiences of community pharmacists in relation to opioid prescribing and dispensing, with a focus on optimizing collaboration and communication.

Methods

An online survey was performed among pharmacists from the province of Quebec, Canada, in 2016. Pharmacists were eligible if registered and working in community pharmacies.

Results

In all, 542 questionnaires were analyzed (participation rate of 8.1%). Pharmacotherapy-related problems were reported in at least 50% of opioid prescriptions: additional drug(s) required (reported by 30% of pharmacists), interaction(s) between opioid(s) and other drug(s) (16%), physician did not meet the general issuing standards for opioid prescriptions (26%) and patient had mild to moderate pain that was easily managed by a nonopioid analgesic (20%). Half of the patients were reported as requesting anticipated refills, possibly indicating abuse or poor pain control. Most pharmacists (89.6%) reported needing to contact physicians in 1 to 3 out of 10 opioid prescriptions, but many pharmacists (71.8%, often or very often) reported difficulties communicating with physicians.

Conclusions

Pharmacists' observations of pharmacotherapy-related problems and patients' unusual behaviours reveal a significant number of issues related to opioid prescribing and dispensing in an outpatient setting. Improved collaboration between physicians and pharmacists appears mandatory to address the issues reported in this study.

The prescription opioid epidemic: a review of qualitative studies on the progression from initial use to abuse

Most research designed to answer the “why” of the prescription opioid epidemic has relied on structured interviews, which rigidly attempt to capture the complex reasons people use opioids. In contrast this systematic literature review focuses on peer-reviewed studies that have used a qualitative approach to examine the development of an opioid-use disorder from the point of initial exposure. Rather than simply providing a “high,” opioids reportedly relieve psychological/emotional problems or provide an escape from life stressors. As use continues, avoidance of withdrawal sickness becomes an overriding concern, with all other benefits playing minor roles in persistent use. These studies indicate that terms used in structured interviews, such as “nontherapeutic use” or variations thereof, poorly capture the complex range of needs opioids satisfy. Both quantitative/structured studies and more qualitative ones, as well as more focused studies, have an important role in better informing prevention and treatment efforts.

Crude estimates of prescription opioid-related misuse and use disorder populations towards informing intervention system need in Canada

BACKGROUND

Numerous interventions aimed at addressing the Canadian 'opioid crisis' have been implemented. However, no empirical estimaes of the number of people with problematic prescription opioid (PO) use exist to inform and guide intervention system needs.

METHODS

The annual numbers of Canadian adults (≥ 15 years) with PO misuse and/or use disorders ('addiction') were estimated by combining data on the prevalence and associated 95% Confidence Intervals (CIs) of PO use in the Canadian population, obtained from national surveys, with PO misuse and use disorders transition probabilities, obtained from high-quality studies in recent meta-analyses. Uncertainty Intervals (UI) were estimated using Monte Carlo simulations.

RESULTS

Population estimates of PO use were highest in 2008, with 5,967,046 (95% CI: 5,635,543-6,326,173) people using POs (representing 21.6% of adults), and lowest in 2015, with 3,941,935 (95% CI: 3,580,842-4,272,937) people using POs (13.1%). Furthermore, PO misuse and use disorders were highest in 2008, with 1,408,223 (95% UI: 878,686-1,951,211; 5.1% of adults) and 525,100 (95% UI 258,288-801,472; 1.9%) people with PO misuse and use disorders respectively. These numbers declined to 930,297 (95% UI: 576,083-1,295,310; 3.1% of adults) and 346,890 (95% UI: 168,310-532,941; 1.2%) people with PO misuse and use disorders, respectively, in 2015.

CONCLUSION

While seemingly declining over-time, the crude population estimates for problematic PO use were high, likely outweighing current intervention capacities. Furthermore, these estimates do not account for the delay of onset and duration of PO misuse and disorders. Thus, more rigorous problem population estimates should be generated to guide interventions.

The OPTIMA study, buprenorphine/naloxone and methadone models of care for the treatment of prescription opioid use disorder: Study design and rationale

BACKGROUND

Rates of non-medical use of opioids, and opioid use disorders (OUD) have been rising throughout North America. Methadone and buprenorphine/naloxone are the recommended first-line treatment options for OUD in Canada. Most studies to date have been conducted among heroin users, in controlled settings, and using similar strict dosing schedules (i.e., daily witnessed ingestion) despite buprenorphine/naloxone's superior safety profile, which allows a more flexible take-home dosing schedule. This study was designed to assess the relative effectiveness of buprenorphine/naloxone- and methadone-based models of opioid agonist therapy (OAT) for the treatment of prescription opioid use disorder (POUD) in routine clinical care.

METHODS

OPTIMA is a multicenter, open-label, pragmatic, randomized, two-arm, non-inferiority, 24-week study comparing the relative effectiveness of buprenorphine/naloxone (provided via flexible take-home doses) to methadone (provided via daily witnessed ingestion) models of OAT for the treatment of POUD. Approximately 276 non-pregnant adults meeting DSM-5 criteria for OUD, currently not in OAT, will be randomized across 7 Canadian sites. The primary outcome is reduction of non-medical opioid use, measured by bi-weekly urine drug screens during the 24-week study period. Secondary outcomes include treatment retention and satisfaction, safety, medication adherence, and patient engagement.

DISCUSSION

The OPTIMA study is the first randomized clinical trial to compare the relative effectiveness of buprenorphine/naloxone (flexible take-home doses) versus methadone (daily witnessed ingestion) models of OAT for POUD in real-world clinical settings. This study will generate urgently needed evidence towards treatment options to guide the health system response to the ongoing opioid crisis.

CLINICAL TRIAL REGISTRATION

NCT03033732.

Epidemiologic trends in substance and opioid misuse-related emergency department visits in Alberta: a cross-sectional time-series analysis

OBJECTIVES

Substance and opioid misuse are growing public health concerns. This study's objectives were to evaluate trends in substance and opioid misuse-related emergency department (ED) visits in Alberta, Canada.

METHODS

This is a cross-sectional time-series analysis utilizing National Ambulatory Care Reporting System ED data from Alberta, Canada. All substance and opioid misuse-related visits made by adults (≥ 18 years) from 2010/11 to 2014/15 were analyzed. Acuity was measured by the Canadian Triage and Acuity Scale (CTAS). Relevant visits were identified by ICD-10 diagnostic coding. Substance and opioid visits over 60 months were compared to all ED visits per 100,000 adult population using regression analysis, while controlling for temporal and seasonal variation. Trends among age and sex subgroups were also evaluated.

RESULTS

From 2010/11 to 2014/15, substance and opioid misuse-related visits increased by 38.0% and 57.3% to 1119 and 118 visits per 100,000 population, respectively. Annual growth rates for substance and opioid visits were 4.4% higher (95% CI: 2.2, 6.7) and 10.6% higher (95% CI: 6.8, 14.6) than all ED visits. The 18-29 year-old category experienced the highest annual growth rate of all age groups, and the annual opioid visit growth rate was 5.6% higher among males than females. Compared to all visits, substance misuse-related visits arrived more frequently by ambulance, were higher acuity, and were hospitalized more often.

CONCLUSION

Substance and opioid misuse-related ED visits increased significantly from 2010 to 2015, especially among younger patients. Future research should elaborate causes and evaluate interventions to curb the growth of this issue.

Increasing availability of illicit and prescription opioids among people who inject drugs in a Canadian setting, 2010-2014

BACKGROUND

Nonmedical use of prescription opioid and illicit opioid has been increasing at an alarming rate in North America over the past decade.

OBJECTIVE

We sought to examine the temporal trends and correlates of the availability of illicit and prescription opioids among people who inject drugs (PWID) in Vancouver, Canada.

METHODS

Data were derived from three prospective cohort studies of PWID in Vancouver between 2010 and 2014. In semiannual interviews, participants reported the availability of five sets of illicit and prescription opioids: (1) heroin; (2) Percocet (oxycodone/acetaminophen), Vicodin (hydrocodone/acetaminophen), or Demerol (meperidine); (3) Dilaudid (hydromorphone); (4) Morphine; (5) oxycontin/OxyNEO (controlled-release oxycodone). We defined perceived availability as immediate (e.g., available within 10 minutes) versus no availability/available after 10 minutes. The trend and correlation of immediate availability were identified by multivariable generalized estimating equations logistic regression.

RESULTS

Among 1584 participants, of which 564 (35.6%) were female, the immediate availability of all illicit and prescribed opioids (except for oxycontin/OxyNEO) increased over time, independent of potential confounders. The Adjusted Odds Ratios of immediate availability associated with every calendar year increase were between 1.09 (95% confidence interval 1.05-1.12) (morphine and Dilaudid) and 1.13 (95% confidence interval 1.09-1.17) (Percocet/Vicodin/Demerol) (all p-values <0.05).

CONCLUSION

The availability of most prescription opioids had continued to increase in recent years among our sample of PWID in Vancouver. Concurrent increases in the availability of heroin were also observed, raising concerns regarding combination of both illicit and prescription opioid use among PWID that could potentially increase the risk of overdose.

Drug use among transgender people in Ontario, Canada: Disparities and associations with social exclusion

INTRODUCTION

We identified the prevalence and correlates of past-year illicit drug use among transgender people in Ontario, Canada, and disparities with the age-standardized non-transgender population.

METHODS

Data on transgender persons aged 16+ (n=406) were obtained from Trans PULSE, a respondent-driven sampling (RDS) survey (2009-2010). Overall and sex-specific estimates of past-year drug use (cocaine and amphetamines, based on data availability) in the reference population were obtained from Ontario residents aged 16+ (n=39, 980) in the Canadian Community Health Survey (2009-2010), and standardized to the overall and gender-specific transgender age distributions. For regression analyses with Trans PULSE data, past-year drug use included drug types associated with high risk of physical, psychological, and social harm to the user, and RDS-II weights were applied to frequencies and prevalence ratios (PR) derived from blockwise logistic regression models.

RESULTS

An estimated 12.3% (95% CI: 7.7, 17.0) of transgender Ontarians had used at least one of the specified drugs in the past year, with no significant difference by gender identity. Transgender Ontarians were more likely to use both cocaine (standardized prevalence difference; SPD=6.8%; 95% CI=1.6, 10.9) and amphetamines (SPD=SPD=1.3%, 95% CI=0.2, 3.1) as compared to the age-standardized non-transgender population. History of transphobic assault, homelessness or underhousing, and sex work were associated with greater drug use among transgender persons.

CONCLUSIONS

The prevalence of cocaine and amphetamine use among transgender people in Ontario, Canada was higher than in the age-standardized reference population. Social exclusion predicted within-group variation in drug use among transgender persons.

The prescription opioid epidemic: a review of qualitative studies on the progression from initial use to abuse

Most research designed to answer the "why" of the prescription opioid epidemic has relied on structured interviews, which rigidly attempt to capture the complex reasons people use opioids. In contrast this systematic literature review focuses on peer-reviewed studies that have used a qualitative approach to examine the development of an opioid-use disorder from the point of initial exposure. Rather than simply providing a "high," opioids reportedly relieve psychological/emotional problems or provide an escape from life stressors. As use continues, avoidance of withdrawal sickness becomes an overriding concern, with all other benefits playing minor roles in persistent use. These studies indicate that terms used in structured interviews, such as "nontherapeutic use" or variations thereof, poorly capture the complex range of needs opioids satisfy. Both quantitative/structured studies and more qualitative ones, as well as more focused studies, have an important role in better informing prevention and treatment efforts.

HCN2 ion channels: basic science opens up possibilities for therapeutic intervention in neuropathic pain

Nociception — the ability to detect painful stimuli — is an invaluable sense that warns against present or imminent damage. In patients with chronic pain, however, this warning signal persists in the absence of any genuine threat and affects all aspects of everyday life. Neuropathic pain, a form of chronic pain caused by damage to sensory nerves themselves, is dishearteningly refractory to drugs that may work in other types of pain and is a major unmet medical need begging for novel analgesics. Hyperpolarisation-activated cyclic nucleotide (HCN)-modulated ion channels are best known for their fundamental pacemaker role in the heart; here, we review data demonstrating that the HCN2 isoform acts in an analogous way as a ‘pacemaker for pain’, in that its activity in nociceptive neurons is critical for the maintenance of electrical activity and for the sensation of chronic pain in pathological pain states. Pharmacological block or genetic deletion of HCN2 in sensory neurons provides robust pain relief in a variety of animal models of inflammatory and neuropathic pain, without any effect on normal sensation of acute pain. We discuss the implications of these findings for our understanding of neuropathic pain pathogenesis, and we outline possible future opportunities for the development of efficacious and safe pharmacotherapies in a range of chronic pain syndromes.

Gender difference in prescription opioid abuse: A focus on oxycodone and hydrocodone

Several data gathered in the last decade indicate an increase of abuse of prescription opioid drugs oxycodone (OXY) and hydrocodone (HYDRO) in women. However, to date there are no conclusive evidences investigating the gender-dependent abuse liability of prescription opioids. This study aims to supply a specific focus on women's data through a selective summary of the literature analyzing gender differences in the pharmacokinetic and pharmacodynamic dimension of OXY and HYDRO. Findings from this study suggest that the majority of OXY and HYDRO pharmacokinetic and pharmacodynamic effects do not differ according to gender, though confirming a significant difference in the incidence of adverse effects as demonstrated by the increased gastrointestinal adverse reactions in female subjects. Although the majority of recent clinical studies include an equal number of female and male subjects, the main outcome parameters do not relate specifically to gender differences. Due to the gender influence in activity of CYP3A4 and its crucial role in metabolism of both OXY than HYDRO, we suggest that assessing pharmacokinetic and pharmacodynamic interactions in clinical studies may be useful to clarify the effect of the higher CYP3A4 activity in female in relation to CYP2D6 genotype. Overall, considering the paucity of data regarding gender differences in European Union, this work highlights that impact of new abuse deterrent formulations should be assessed with a special focus on data concerning female subjects.

A cross-sectional examination of medicinal substance abuse and use of nonmedicinal substances among Canadian youth: findings from the 2012-2013 Youth Smoking Survey

BACKGROUND

Medicinal substance abuse is prevalent in Canada; however, little is known about patterns of abuse among young people. In this study, we sought to characterize the abuse of medicinal substances, such as prescription medications and selected over-the-counter substances, as well as that of licit and illicit nonmedicinal substances, using a nationally representative sample of young people.

METHODS

Cross-sectional, nationally representative data for children in grades 7-12 were obtained from Health Canada's 2012-2013 Youth Smoking Survey (n = 38 667). Multinomial regression analyses were conducted to examine subgroup differences in medicinal substance abuse and comorbid abuse of both medicinal and nonmedicinal substances.

RESULTS

About 5% of youth reported abusing medicinal substances in the previous year. Dextromethorphan, a substance found in many cough and cold syrups, was the most widely abused (2.9%), followed by pain medications (2.6%), sleeping medications (1.8%), stimulants (1.7%) and sedatives (1.0%). Abuse of nonmedicinal substances aside from tobacco and alcohol was reported by 21.3% of the population, and abuse of any substances was detected in 23.0% of the surveyed population. Girls at each grade level reported higher rates of abuse of medicinal substances than boys. Regional differences were seen with regard to the types of substances abused across Canada.

INTERPRETATION

A substantial minority of Canadian youth report abusing medicinal substances, including over-the-counter medications (e.g., cough syrup) and prescriptions medications (e.g., pain medication). In contrast to nonmedicinal substances, girls were more likely than boys to report abuse of medicinal substances.

Estimating the health care burden of prescription opioid abuse in five European countries

Background

Opioid abuse, including abuse of prescription opioids (“RxOs”) and illicit substances like heroin, is a serious public health issue in Europe. Currently, there is limited data on the magnitude of RxO abuse in Europe, despite increasing public and scientific interest in the issue. The purpose of this study was to use the best-available data to derive comparable estimates of the health care burden of RxO abuse in France, Germany, Italy, Spain, and the United Kingdom (EU5).

Methods

Published data on the prevalence of problem opioid use and the share of opioid abuse patients reporting misuse of non-heroin opioids were used to estimate the prevalence of RxO abuse in the EU5 countries. The costs of RxO abuse were calculated by applying published estimates of the incremental health care costs of opioid abuse to country-specific estimates of the costs of chronic pain conditions. These estimates were input into an economic model that quantified the health care burden of RxO abuse in each of the EU5 countries. Sensitivity analyses examined key assumptions.

Results

Based on best-available current data, prevalence estimates of RxO abuse ranged from 0.7 to 13.7 per 10,000 individuals across the EU5 countries. Estimates of the incremental health care costs of RxO abuse ranged from €900 to €2,551 per patient per year. The annual health care cost burden of RxO abuse ranged from €6,264 to €279,927 per 100,000 individuals across the EU5 countries.

Conclusion

This study suggests that RxO abuse imposes a cost burden on health systems in the five largest European countries. The extent of RxO abuse in Europe should be monitored given the potential for change over time. Continued efforts should be made to collect reliable data on the prevalence and costs of RxO abuse in Europe to facilitate an accurate characterization of the extent of this potentially growing problem.

Illicit drug use and harms, and related interventions and policy in Canada: A narrative review of select key indicators and developments since 2000

BACKGROUND

By the year 2000, Canada faced high levels of illicit drug use and related harms. Simultaneously, a fundamental tension had raisen between continuing a mainly repression-based versus shifting to a more health-oriented drug policy approach. Despite a wealth of new data and numerous individual studies that have emerged since then, no comprehensive review of key indicators and developments of illicit drug use/harm epidemiology, interventions and law/policy exist; this paper seeks to fill this gap.

METHODS

We searched and reviewed journal publications, as well as key reports, government publications, surveys, etc. reporting on data and information since 2000. Relevant data were selected and extracted for review inclusion, and subsequently grouped and narratively summarized in major topical sub-theme categories.

RESULTS

Cannabis use has remained the principal form of illicit drug use; prescription opioid misuse has arisen as a new and extensive phenomenon. While new drug-related blood-borne-virus transmissions declined, overdose deaths increased in recent years. Acceptance and proliferation of - mainly local/community-based - health measures (e.g., needle exchange, crack paraphernalia or naloxone distribution) aiming at high-risk drug users has evolved, though reach and access limitations have persisted; Vancouver's 'supervised injection site' has attracted continued attention yet remains un-replicated elsewhere in Canada. While opioid maintenance treatment utilization increased, access to treatment for key (e.g., infectious disease, psychiatric) co-morbidities among drug users remained limited. Law enforcement continued to principally focus on cannabis and specifically cannabis users. 'Drug treatment courts' were introduced but have shown limited effectiveness; several attempts cannabis control law reform have failed, except for the recent establishment of 'medical cannabis' access provisions.

CONCLUSIONS

While recent federal governments introduced several law and policy measures reinforcing a repression approach to illicit drug use, lower-level jurisdictions (e.g., provincial/municipal levels) and non-governmental organizations increasingly promoted social- and health-oriented intervention frameworks and interventions, therefore creating an increasingly bifurcated - and inherently contradictory - drug policy landscape and reality in Canada.

Drug use patterns predict risk of non-fatal overdose among street-involved youth in a Canadian setting

BACKGROUND

Non-fatal drug overdose is a major cause of morbidity among people who use drugs, although few studies have examined this risk among street-involved youth. We sought to determine the risk factors associated with non-fatal overdose among Canadian street-involved youth who reported illicit drug use.

METHODS

Using data from a prospective cohort of street-involved youth in Vancouver, Canada, we identified youth without a history of overdose and employed Cox regression analyses to determine factors associated with time to non-fatal overdose between September 2005 and May 2012.

RESULTS

Among 615 participants, 98 (15.9%) reported a non-fatal overdose event during follow-up, resulting in an incidence density of 7.67 cases per 100 person-years. In multivariate Cox regression analyses, binge drug use (adjusted hazard ratio [AHR]=1.85; 95% confidence interval [CI]=1.20-2.84), non-injection crystal methamphetamine use (AHR=1.70; 95% CI=1.12-2.58), non-injection prescription opiate use (AHR=2.56; 95% CI=1.36-4.82), injection prescription opiate use (AHR=2.49; 95% CI=1.40-4.45) and injection heroin use (AHR=1.85; 95% CI=1.14-3.00) were positively associated with time to non-fatal overdose. Social, behavioural and demographic factors were not significantly associated with time to non-fatal overdose event.

CONCLUSIONS

Rates of non-fatal overdose were high among street-involved youth. Drug use patterns, in particular prescription opiate use, were associated with overdose. These findings underscore the importance of addiction treatment and prevention efforts aimed at reducing the risk of overdose among youth.

Prevalence and correlates of nonmedical prescription opioid use among a cohort of sex workers in Vancouver, Canada

BACKGROUND

The nonmedical use of prescription opioids (POs) is a major public health concern, causing extensive morbidity and mortality in North America. Canada has the second highest consumption rate of POs globally and data indicate nonmedical PO use (NPOU) is growing among key populations and increasingly available in street-level drug markets. Despite accumulating evidence documenting the rise of NPOU, few studies have systematically examined NPOU in Canada among key vulnerable populations, such as sex workers. This study prospectively evaluated the prevalence and correlates of NPOU within a Vancouver cohort of sex workers over three-years follow-up.

METHODS

Data were drawn from an open prospective cohort, AESHA (An Evaluation of Sex Workers Health Access) in Metro Vancouver, Canada (2010-2013). Women were recruited through outreach from outdoor street locations and indoor venues. Bivariate and multivariable logistic regression using Generalized Estimating Equations (GEE) were used to examine social and structural correlates of NPOU over 36 months.

RESULTS

Of the 692 sex workers at baseline, close to one-fifth (n=130, 18.8%) reported NPOU (injection or non-injection) in the last six months. In multivariable GEE analyses, factors independently correlated with recent NPOU were: exchanging sex while high (AOR 3.26, 95%CI 2.29-4.64), police harassment/arrest (AOR 1.83, 95%CI 1.43-2.35), intimate partner injects drugs (AOR 1.66, 95%CI 1.11-2.49), and recent physical/sexual intimate partner violence (AOR 1.65, 95%CI 1.21-2.24).

CONCLUSION

Our results demonstrate that nearly one-fifth of sex workers in Metro Vancouver report NPOU. Factors independently statistically associated with NPOU included exchanging sex while high, police harassment/arrest, a drug injecting intimate partner and recent physical/sexual intimate partner violence. The high prevalence of NPOU use among sex workers underscores the need for further prevention and management strategies tailored to this key population. The correlates of NPOU uncovered here suggest that structural interventions may be further implemented to ameliorate this growing concern.