Patterns and history of prescription drug use among opioid-related drug overdose cases in British Columbia, Canada, 2015-2016

Dynamics of overdose and non-overdose mortality among people living with HIV amidst the illicit drug toxicity crisis in British Columbia

We sought to characterize overdose and non-overdose mortality among PLWH amidst the illicit drug toxicity crisis in British Columbia, Canada. A population-based analysis of PLWH (age ≥19) in British Columbia accessing healthcare from April 1996 to March 2017 was conducted using data from the Seek and Treat for Optimal Prevention of HIV/AIDS (STOP HIV/AIDS) cohort linkage. Underlying causes of deaths were stratified into overdose and non-overdose causes. We compared (bivariate analysis) health-related characteristics and prescription history between PLWH died of overdose and non-overdose causes between April 2009 and March 2017. Among 9,180 PLWH, we observed 962 deaths (142 [14.7%] overdoses; 820 [85.2%] other causes). Compared to those who died from other causes, those who died of overdose were significantly younger (median age [Q, Q3]: 46 years [42, 52] vs. 54 years [48, 63]); had an indication of chronic pain (35.9% vs. 27.1%) and hepatitis C virus (64.8% vs. 50.4%), but fewer experienced hospitalization in the year before death. PLWH who died were most likely to be prescribed with opioids (>50%) and least likely with opioid agonist therapy (<10%) in a year before death. These findings highlight the syndemic of substance use, HCV, and chronic pain, and how the crisis is unqiuely impacting females and younger people.

Identification of Factors Necessary for Gatekeeper of Overdose

Overdose has become a global social problem. The Japanese government requires gatekeeper training to detect and prevent indicators of overdose and suicide. However, knowledge of necessary factors for the gatekeeper of overdose (patient intervention) is limited. This study aimed to investigate the characteristics of individuals who experienced intervening persons expected to overdose, and to identify the factors required of gatekeepers. A Google form was used to survey 298 pharmacists and registered sellers in Japan. We searched for factors by logistic analysis. Knowledge of prescription drugs used for overdose was higher among pharmacists than among registered sellers. Conversely, pharmacists and registered sellers had similar knowledge about OTC drugs. Overall multivariate logistic regression analysis revealed countermeasures against overdose at their workplace (odds ratio (OR): 4.01, 95% confidence interval (CI): 2.25-7.15, p < 0.01) and knowledge that overdose is on the rise (OR: 1.93, 95% CI: 1.04-3.69, p < 0.05) to be significantly associated with intervention experience as a gatekeeper. Countermeasures against overdose at their workplace (OR: 2.40, 95% CI: 1.10-5.25, p < 0.05) in pharmacists and years of work experience (OR: 1.13, 95% CI: 1.04-1.24, p < 0.05), countermeasure against overdose at their workplace (OR: 3.43, 95% CI: 1.18-10.0, p < 0.05), and willingness to participate in study sessions and workshops on overdose (OR: 3.50, 95% CI: 1.51-8.10, p < 0.05) in registered seller were significantly associated with intervention experience as a gatekeeper. These results are useful evidences for countermeasures and gatekeeper training for overdose at pharmacies and drugstores in the community.

The Impact of Preoperative Patient Education on Postoperative Pain, Opioid Use, and Psychological Outcomes: A Narrative Review

Background

Recent studies have shown that preoperative education can positively impact postoperative recovery, improving postoperative pain management and patient satisfaction. Gaps in preoperative education regarding postoperative pain and opioid use may lead to increased patient anxiety and persistent postoperative opioid use.

Objectives

The objective of this narrative review was to identify, examine, and summarize the available evidence on the use and effectiveness of preoperative educational interventions with respect to postoperative outcomes.

Method

The current narrative review focused on studies that assessed the impact of preoperative educational interventions on postoperative pain, opioid use, and psychological outcomes. The search strategy used concept blocks including "preoperative" AND "patient education" AND "elective surgery," limited to the English language, humans, and adults, using the MEDLINE ALL database. Studies reporting on preoperative educational interventions that included postoperative outcomes were included. Studies reporting on enhanced recovery after surgery protocols were excluded.

Results

From a total of 761 retrieved articles, 721 were screened in full and 34 met criteria for inclusion. Of 12 studies that assessed the impact of preoperative educational interventions on postoperative pain, 5 reported a benefit for pain reduction. Eight studies examined postoperative opioid use, and all found a significant reduction in opioid consumption after preoperative education. Twenty-four studies reported on postoperative psychological outcomes, and 20 of these showed benefits of preoperative education, especially on postoperative anxiety.

Conclusion

Preoperative patient education interventions demonstrate promise for improving postoperative outcomes. Preoperative education programs should become a prerequisite and an available resource for all patients undergoing elective surgery.

Evaluation of audit and feedback to family physicians on prescribing of opioid analgesics to opioid-naïve patients: A pragmatic randomized delay trial

BACKGROUND

Exposure to opioid analgesics have historically raised concern for a risk of developing opioid use disorder. Prescriber audit-and-feedback interventions may reduce opioid prescribing, but some studies have shown detrimental effects for current users. We examined the effectiveness of an audit and feedback intervention, named Portrait, to reduce initiation of opioid analgesics among opioid-naïve patients experiencing pain.

METHODS

REDONNA was a single-blinded, two-arm (Early vs Delayed mailing) randomized trial of a portrait for eligible family physicians (FPs) in British Columbia (BC), Canada. The primary outcome was the change in the number of initiations of opioid analgesic prescriptions written by FPs for acute/chronic pain management. We compared outcomes for a 6-month window before vs. after each mailed intervention, using differences in percent differences (DPD) with 95% confidence intervals (CI) and odds ratios (OR) from logistic regressions adjusted for clustering of patients by FP.

RESULTS

In the Early (n = 2260) and Delayed (n = 2156) groups, opioid initiations per month were the same in the Before (2.10 Early; 2.06 Delayed) and After (1.94 Early; 1.95 Delayed) windows. The DPD was -2.1% (CI: -4.4% to 0.3%), and ORs were: 0.98 (CI: 0.96 to 1.01) for any opioid, 0.97 (CI: 0.94 to 1.01) for codeine (62% of initiations), and 1.0 (CI: 0.97 to 1.07) for tramadol (25% of initiations). There were no differences in mean quantity of tablets, mean milligrams of morphine equivalents (MME), or mean number of days.

CONCLUSION

Portrait had no impact on FPs' rates of prescribing opioid analgesics to opioid-naïve patients experiencing pain.

TRIAL REGISTRATION

The study was registered prospectively on 30 March 2020 at the ISRCTN Register (https://www.isrctn.com/ISRCTN34246811).

Examining fentanyl and its analogues in the unregulated drug supply of British Columbia, Canada using drug checking technologies

INTRODUCTION

The emergence of fentanyl and its analogues have contributed to a drastic rise in overdose-related mortality in recent years. The objective of this study was to determine the number of drug checking samples containing fentanyl and fentanyl analogues using both point of care and confirmatory drug checking technologies.

METHODS

Point-of-care drug checking data, using a combination of fentanyl immunoassay strips and Fourier-transform infrared spectroscopy (FTIR), were collected at harm reduction sites in Vancouver and Surrey, British Columbia. Based on current recommendations from the British Columbia Centre on Substance Use Drug Checking Project, a subset of these samples was sent for confirmatory analysis using quantitative nuclear resonance spectroscopy, gas chromatography-mass spectrometry and/or liquid chromatography-mass spectrometry.

RESULTS

A total of 22,916 samples were tested using FTIR and fentanyl immunoassay strips, of which 6125 (29%) were positive for fentanyl and/or fentanyl analogues. FTIR identified a fentanyl analogue in five samples (all carfentanil). Of the 1467 samples sent for confirmatory analysis, fentanyl was identified in 855 (58%) and fentanyl analogues in 85 (6%), including: carfentanil (n = 56), acetyl fentanyl (n = 15), furanyl fentanyl (n = 9) and cyclopropyl fentanyl (n = 5).

DISCUSSION AND CONCLUSION

Our research found that FTIR does not consistently distinguish between fentanyl and its analogues at point of care and that highly sensitive confirmatory drug checking technologies are needed to identify fentanyl analogues. These findings underscore the limitations of current drug checking technologies and the importance of using both point of care and confirmatory drug checking initiatives for monitoring changes in the drug supply.

Drug overdose and the risk of cardiovascular diseases: a nested case-control study

BACKGROUND

North America has been experiencing an unprecedented epidemic of drug overdose. This study investigated the associations of drug overdose with the risk of cardiovascular disease (CVD) and 11 major CVD subtypes.

METHODS

This nested case-control study was based on a cohort of 20% random sample of residents in British Columbia, Canada, who were aged 18-80 years and did not have known CVD at baseline (n = 617,863). During a 4-year follow-up period, persons who developed incident CVD were identified as case subjects, and the onset date of CVD was defined as the index date. For each case subject, we used incidence density sampling to randomly select up to five control subjects from the cohort members who were alive and did not have known CVD by the index date, were admitted to an emergency department or hospital on the index date for non-CVD causes, and were matched on age, sex, and region of residence. Overdose exposure on the index date and each of the previous 5 days was examined for each subject.

RESULTS

This study included 16,113 CVD case subjects (mean age 53 years, 59% male) and 66,875 control subjects. After adjusting for covariates, overdose that occurred on the index date was strongly associated with CVD [odds ratio (OR), 2.9; 95% confidence interval (CI), 2.4-3.5], especially for arrhythmia (OR, 8.6; 95% CI, 6.2-12.0), ischemic stroke (OR, 5.3; 95% CI, 2.0-14.1), hemorrhagic stroke (OR, 3.1; 95% CI, 1.2-8.3), and myocardial infarction (OR, 3.0; 95% CI, 1.5-5.8). The CVD risk was decreased but remained significantly elevated for overdose that occurred on the previous day, and was not observed for overdose that occurred on each of the previous 2-5 days.

CONCLUSIONS

Drug overdose appears to be associated with increased risk of cardiovascular diseases.

Individualized Prospective Prediction of Opioid Use Disorder

OBJECTIVE

Opioid use disorder (OUD) is a chronic relapsing disorder with a problematic pattern of opioid use, affecting nearly 27 million people worldwide. Machine learning (ML)-based prediction of OUD may lead to early detection and intervention. However, most ML prediction studies were not based on representative data sources and prospective validations, limiting their potential to predict future new cases. In the current study, we aimed to develop and prospectively validate an ML model that could predict individual OUD cases based on representative large-scale health data.

METHOD

We present an ensemble machine-learning model trained on a cross-linked Canadian administrative health data set from 2014 to 2018 (n  =  699,164), with validation of model-predicted OUD cases on a hold-out sample from 2014 to 2018 (n  =  174,791) and prospective prediction of OUD cases on a non-overlapping sample from 2019 (n  =  316,039). We used administrative records of OUD diagnosis for each subject based on International Classification of Diseases (ICD) codes.

RESULTS

With 6409 OUD cases in 2019 (mean [SD], 45.34 [14.28], 3400 males), our model prospectively predicted OUD cases at a high accuracy (balanced accuracy, 86%, sensitivity, 93%; specificity 79%). In accord with prior findings, the top risk factors for OUD in this model were opioid use indicators and a history of other substance use disorders.

CONCLUSION

Our study presents an individualized prospective prediction of OUD cases by applying ML to large administrative health datasets. Such prospective predictions based on ML would be essential for potential future clinical applications in the early detection of OUD.

Discontinuation and tapering of prescribed opioids and risk of overdose among people on long-term opioid therapy for pain with and without opioid use disorder in British Columbia, Canada: A retrospective cohort study

BACKGROUND

The overdose crisis in North America has prompted system-level efforts to restrict opioid prescribing for chronic pain. However, little is known about how discontinuing or tapering prescribed opioids for chronic pain shapes overdose risk, including possible differential effects among people with and without concurrent opioid use disorder (OUD). We examined associations between discontinuation and tapering of prescribed opioids and risk of overdose among people on long-term opioid therapy for pain, stratified by diagnosed OUD and prescribed opioid agonist therapy (OAT) status.

METHODS AND FINDINGS

For this retrospective cohort study, we used a 20% random sample of residents in the provincial health insurance client roster in British Columbia (BC), Canada, contained in the BC Provincial Overdose Cohort. The study sample included persons aged 14 to 74 years on long-term opioid therapy for pain (≥90 days with ≥90% of days on therapy) between October 2014 and June 2018 (n = 14,037). At baseline, 7,256 (51.7%) persons were female, the median age was 55 years (quartile 1-3: 47-63), 227 (1.6%) persons had been diagnosed with OUD (in the past 3 years) and recently (i.e., in the past 90 days) been prescribed OAT, and 483 (3.4%) had been diagnosed with OUD but not recently prescribed OAT. The median follow-up duration per person was 3.7 years (quartile 1-3: 2.6-4.0). Marginal structural Cox regression with inverse probability of treatment weighting (IPTW) was used to estimate the effect of prescribed opioid treatment for pain status (discontinuation versus tapered therapy versus continued therapy [reference]) on risk of overdose (fatal or nonfatal), stratified by the following groups: people without diagnosed OUD, people with diagnosed OUD receiving OAT, and people with diagnosed OUD not receiving OAT. In marginal structural models with IPTW adjusted for a range of demographic, prescription, comorbidity, and social-structural exposures, discontinuing opioids (i.e., ≥7-day gap[s] in therapy) was associated with increased overdose risk among people without OUD (adjusted hazard ratio [AHR] = 1.44; 95% confidence interval [CI] 1.12, 1.83; p = 0.004), people with OUD not receiving OAT (AHR = 3.18; 95% CI 1.87, 5.40; p < 0.001), and people with OUD receiving OAT (AHR = 2.52; 95% CI 1.68, 3.78; p < 0.001). Opioid tapering (i.e., ≥2 sequential decreases of ≥5% in average daily morphine milligram equivalents) was associated with decreased overdose risk among people with OUD not receiving OAT (AHR = 0.31; 95% CI 0.14, 0.67; p = 0.003). The main study limitations are that the outcome measure did not capture overdose events that did not result in a healthcare encounter or death, medication dispensation may not reflect medication adherence, residual confounding may have influenced findings, and findings may not be generalizable to persons on opioid therapy in other settings.

CONCLUSIONS

Discontinuing prescribed opioids was associated with increased overdose risk, particularly among people with OUD. Prescribed opioid tapering was associated with reduced overdose risk among people with OUD not receiving OAT. These findings highlight the need to avoid abrupt discontinuation of opioids for pain. Enhanced guidance is needed to support prescribers in implementing opioid therapy tapering strategies with consideration of OUD and OAT status.

Concurrent use of opioids and stimulants and risk of fatal overdose: A cohort study

Background

Stimulant use has been rising among people with opioid use disorder in recent years in North America, alongside a parallel rise in illicit drug toxicity (overdose) deaths. This study aimed to examine the association between stimulant use and overdose mortality.

Methods

Data from a universal health insurance client roster were used to identify a 20% random general population sample (aged ≥12) in British Columbia, Canada between January 1 2015 and December 31 2018 (N = 1,089,682). Provincial health records were used to identify people who used opioids and/or stimulants. Fatal overdose observed during follow-up (January 12,015- December 312,018) was retrieved from Vital Statistics Death Registry and BC Coroners Service Data. Potential confounders including age, sex, health region, comorbidities and prescribed medications were retrieved from the provincial client roster and health records.

Results

We identified 7460 people who used stimulants and or opioids. During follow-up there were 272 fatal overdose events. People who used both opioids and stimulants had more than twice the hazard of fatal overdose (HR: 2.02, 95% CI: 1.47-2.78, p < 0.001) compared to people who used opioids only. The hazard of death increased over time among people who used both opioids and stimulants.

Conclusions

There is an urgent need to prioritize the service needs of people who use stimulants to reduce overdose mortality in British Columbia. Findings have relevance more broadly in other North American settings, where similar trends in opioid and stimulant polysubstance use have been observed.

Long-term prescription opioid users' risk for new-onset depression increases with frequency of use

ABSTRACT

Long-term opioid therapy (LTOT) is associated with increased risk for depression. It is not known if the frequency of opioid use during LTOT is associated with new-onset depression. We used Optum's de-identified Integrated Claims-Clinical dataset (2010-2018) to create a cohort of 5146 patients, 18 to 80 years of age, with an encounter or claims in the year before new LTOT. New LTOT was defined by >90-day opioid use after remaining opioid free for 6 months. Opioid use frequency during the first 90 days of LTOT was categorized into occasional use (<50% days covered), intermittent use (50% to <80% days covered), frequent use (80% to <90% days covered), and daily use (≥90% days covered). Propensity scores and inverse probability of exposure weighting controlled for confounding in models estimating risk for new-onset depression. Patients were on average 54.5 (SD ± 13.6) years of age, 55.7% were female, 72.5% were White, and 9.5% were African American. After controlling for confounding, daily users (hazard ratio = 1.40; 95% confidence interval: 1.14-1.73) and frequent users (hazard ratio = 1.34; 95% confidence interval: 1.05-1.71) were significantly more likely to develop new-onset depression compared with occasional users. This association remained after accounting for the contribution of post-index pain diagnoses and opioid use disorder. In LTOT, risk for new depression episodes is up to 40% greater in near-daily users compared with occasional users. Patients could reduce depression risk by avoiding opioid use on as many low pain days as possible. Repeated screening for depression during LTOT is warranted.

Mental disorder and opioid overdose: a systematic review

PURPOSE

This systematic review summarizes and presents the current state of research quantifying the relationship between mental disorder and overdose for people who use opioids.

METHODS

The protocol was published in Open Science Framework. We used the PECOS framework to frame the review question. Studies published between January 1, 2000, and January 4, 2021, from North America, Europe, the United Kingdom, Australia, and New Zealand were systematically identified and screened through searching electronic databases, citations, and by contacting experts. Risk of bias assessments were performed. Data were synthesized using the lumping technique.

RESULTS

Overall, 6512 records were screened and 38 were selected for inclusion. 37 of the 38 studies included in this review show a connection between at least one aspect of mental disorder and opioid overdose. The largest body of evidence exists for internalizing disorders generally and mood disorders specifically, followed by anxiety disorders, although there is also moderate evidence to support the relationship between thought disorders (e.g., schizophrenia, bipolar disorder) and opioid overdose. Moderate evidence also was found for the association between any disorder and overdose.

CONCLUSION

Nearly all reviewed studies found a connection between mental disorder and overdose, and the evidence suggests that having mental disorder is associated with experiencing fatal and non-fatal opioid overdose, but causal direction remains unclear.

Association Between Prescription Opioid Therapy for Noncancer Pain and Hepatitis C Virus Seroconversion

IMPORTANCE

Initiation of injection drug use may be more frequent among people dispensed prescription opioid therapy for noncancer pain, potentially increasing the risk of hepatitis C virus (HCV) acquisition.

OBJECTIVE

To assess the association between medically dispensed long-term prescription opioid therapy for noncancer pain and HCV seroconversion among individuals who were initially injection drug use-naive.

DESIGN, SETTING, AND PARTICIPANTS

A population-based, retrospective cohort study of individuals tested for HCV in British Columbia, Canada, with linkage to outpatient pharmacy dispensations, was conducted. Individuals with an initial HCV-negative test result followed by 1 additional test between January 1, 2000, and December 31, 2017, and who had no history of substance use at baseline (first HCV-negative test), were included. Participants were followed up from baseline to the last HCV-negative test or estimated date of seroconversion (midpoint between HCV-positive and the preceding HCV-negative test).

EXPOSURES

Episodes of prescription opioid use for noncancer pain were defined as acute (<90 days) or long-term (≥90 days). Prescription opioid exposure status (long-term vs prescription opioid-naive/acute) was treated as time-varying in survival analyses. In secondary analyses, long-term exposure was stratified by intensity of use (chronic vs. episodic) and by average daily dose in morphine equivalents (MEQ).

MAIN OUTCOMES AND MEASURES

Multivariable Cox regression models were used to assess the association between time-varying prescription opioid status and HCV seroconversion.

RESULTS

A total of 382 478 individuals who had more than 1 HCV test were included, of whom more than half were female (224 373 [58.7%]), born before 1974 (201 944 [52.8%]), and younger than 35 years at baseline (196 298 [53.9%]). Participants were followed up for 2 057 668 person-years and 1947 HCV seroconversions occurred. Of the participants, 41 755 people (10.9%) were exposed to long-term prescription opioid therapy at baseline or during follow-up. The HCV seroconversion rate per 1000 person-years was 0.8 among the individuals who were prescription opioid-naive/acute (1489 of 1947 [76.5%] seroconversions; 0.4% seroconverted within 5 years) and 2.1 with long-term prescription opioid therapy (458 of 1947 [23.5%] seroconversions; 1.1% seroconverted within 5 years). In multivariable analysis, exposure to long-term prescription opioid therapy was associated with a 3.2-fold (95% CI, 2.9-3.6) higher risk of HCV seroconversion (vs prescription opioid-naive/acute). In separate Cox models, long-term chronic use was associated with a 4.7-fold higher risk of HCV seroconversion (vs naive/acute use 95% CI, 3.9-5.8), and long-term higher-dose use (≥90 MEQ) was associated with a 5.1-fold higher risk (vs naive/acute use 95% CI, 3.7-7.1).

CONCLUSIONS AND RELEVANCE

In this cohort study of people with more than 1 HCV test, long-term prescription opioid therapy for noncancer pain was associated with a higher risk of HCV seroconversion among individuals who were injection drug use-naive at baseline or at prescription opioid initiation. These results suggest injection drug use initiation risk is higher among people dispensed long-term therapy and may be useful for informing approaches to identify and prevent HCV infection. These findings should not be used to justify abrupt discontinuation of long-term therapy, which could increase risk of harms.

Opioid analgesic prescribing for opioid-naïve individuals prior to identification of opioid use disorder in British Columbia, Canada

BACKGROUND AND AIMS

Prescription opioid analgesics have contributed to the development of opioid use disorder (OUD) in many individuals. We aimed to characterize non-cancer opioid prescribing for opioid-naive individuals prior to OUD identification.

DESIGN

Population-based retrospective cohort study using six linked health administrative databases.

SETTING

British Columbia (BC), Canada.

PARTICIPANTS

People with OUD between 1 January 2001 and 30 September 2018 who initiated opioid analgesic therapy for non-cancer pain prior to OUD identification.

MEASUREMENTS

Dose (morphine milligram equivalent per day), days prescribed and clinical guideline non-concordance for initial opioid prescriptions (dose ≥ 90 morphine milligram equivalent per day; ≥ 7 days prescribed; concomitant sedative prescription). We estimated the probability of non-concordant initial prescriptions by source (inpatient post-discharge, non-inpatient acute, non-acute) using logistic regression, adjusting for individual characteristics and comorbidities.

FINDINGS

Among 66 372 individuals identified with OUD from 2001 to 2018, 21 331 (32.1%) received opioid analgesics prior to OUD identification. This proportion increased from 3.0% in 2001 to 41.0% in 2011, before decreasing to 34.2% in 2017. Roughly half of opioid prescriptions were attributed to non-acute care visits, peaking at 56.8% in 2007, while the proportion from inpatient visits increased from 19.7% in 2001 to 28.5% in 2017. The predicted probability of receiving non-guideline concordant prescriptions declined over time-periods across all three measures for inpatient and non-inpatient acute care, while remaining stable for non-acute care. In particular, the predicted probability of receiving ≥ 7-day prescriptions following inpatient visits decreased from 53.3% [95% confidence interval (CI) = 50.9, 55.8%] in 2001-06 to 37.2% (95% CI = 33.9, 40.5%) in 2013-18.

CONCLUSIONS

Among the 66 372 individuals in British Columbia, Canada diagnosed with opioid use disorder between 2001 and 2018, more than 32% were earlier prescribed non-cancer opioid analgesics. The proportion who had received an opioid analgesic prescription prior to OUD identification peaked at more than 40% in 2011, before stabilizing between 2011 and 2016 and declining thereafter. Guideline concordance improved over time for high-dose and concomitant sedative prescribing.

Prescription opioid treatment for non-cancer pain and initiation of injection drug use: large retrospective cohort study

OBJECTIVE

To assess the association between long term prescription opioid treatment medically dispensed for non-cancer pain and the initiation of injection drug use (IDU) among individuals without a history of substance use.

DESIGN

Retrospective cohort study.

SETTING

Large administrative data source (containing information for about 1.7 million individuals tested for hepatitis C virus or HIV in British Columbia, Canada) with linkage to administrative health databases, including dispensations from community pharmacies.

PARTICIPANTS

Individuals age 11-65 years and without a history of substance use (except alcohol) at baseline.

MAIN OUTCOME MEASURES

Episodes of prescription opioid use for non-cancer pain were identified based on drugs dispensed between 2000 and 2015. Episodes were classified by the increasing length and intensity of opioid use (acute (lasting <90 episode days), episodic (lasting ≥90 episode days; with <90 days' drug supply and/or <50% episode intensity), and chronic (lasting ≥90 episode days; with ≥90 days' drug supply and ≥50% episode intensity)). People with a chronic episode were matched 1:1:1:1 on socioeconomic variables to those with episodic or acute episodes and to those who were opioid naive. IDU initiation was identified by a validated administrative algorithm with high specificity. Cox models weighted by inverse probability of treatment weights assessed the association between opioid use category (chronic, episodic, acute, opioid naive) and IDU initiation.

RESULTS

59 804 participants (14 951 people from each opioid use category) were included in the matched cohort, and followed for a median of 5.8 years. 1149 participants initiated IDU. Cumulative probability of IDU initiation at five years was highest for participants with chronic opioid use (4.0%), followed by those with episodic use (1.3%) and acute use (0.7%), and those who were opioid naive (0.4%). In the inverse probability of treatment weighted Cox model, risk of IDU initiation was 8.4 times higher for those with chronic opioid use versus those who were opioid naive (95% confidence interval 6.4 to 10.9). In a sensitivity analysis limited to individuals with a history of chronic pain, cumulative risk for those with chronic use (3.4% within five years) was lower than the primary results, but the relative risk was not (hazard ratio 9.7 (95% confidence interval 6.5 to 14.5)). IDU initiation was more frequent at higher opioid doses and younger ages.

CONCLUSIONS

The rate of IDU initiation among individuals who received chronic prescription opioid treatment for non-cancer pain was infrequent overall (3-4% within five years) but about eight times higher than among opioid naive individuals. These findings could have implications for strategies to prevent IDU initiation, but should not be used as a reason to support involuntary tapering or discontinuation of long term prescription opioid treatment.

Sensitivity and specificity of self-reported psychiatric diagnoses amongst patients treated for opioid use disorder

BACKGROUND

Patients with opioid use disorder (OUD) frequently present with comorbid psychiatric illnesses which have significant implications for their treatment outcomes. Notably, these are often identified by self-report. Our study examined the sensitivity and specificity of self-reported psychiatric diagnoses against a structured diagnostic interview in a cohort of patients receiving outpatient pharmacological treatment for OUD.

METHODS

Using cross-sectional data from adults receiving outpatient opioid agonist treatment for OUD in clinics across Ontario, Canada, we compared participants' self-reported psychiatric diagnoses with those identified by the Mini Neuropsychiatric Interview (MINI) Version 6.0 administered at the time of study entry. Sensitivity and specificity were calculated for self-report of psychiatric diagnoses.

RESULTS

Amongst a sample of 683 participants, 24% (n = 162) reported having a comorbid psychiatric disorder. Only 104 of these 162 individuals (64%) reporting a comorbidity met criteria for a psychiatric disorder as per the MINI; meanwhile, 304 (75%) participants who self-reported no psychiatric comorbidity were in fact identified to meet MINI criteria for a psychiatric disorder. The sensitivity and specificity for any self-reported psychiatric diagnoses were 25.5% (95% CI 21.3, 30.0) and 78.9% (95% CI 73.6, 83.6), respectively.

CONCLUSIONS

Our findings raise questions about the utility of self-reported psychiatric comorbidity in patients with OUD, particularly in the context of low sensitivity of self-reported diagnoses. Several factors may contribute to this including remittance and relapse of some psychiatric illnesses, underdiagnosis, and the challenge of differentiating psychiatric and substance-induced disorders. These findings highlight that other methods should be considered in order to identify comorbid psychiatric disorders in patients with OUD.

Opioid prescribing practice standard in British Columbia, Canada: Rationale, controversies, and directions

British Columbia (BC) has been the hardest hit province in Canada's ongoing overdose epidemic. As part of the province-level response, the College of Physicians and Surgeons of British Columbia (CPSBC) implemented the "Safe Prescribing of Drugs with Potential for Misuse/Diversion" practice standard in June 2016. The practice standard established specific dose and quantity thresholds for opioid prescribing as professional and ethical conduct expectations for physicians in BC. This supply side intervention was based on expert interpretation of available evidence of non-superiority of opioid treatments to non-opioid treatments. However, the potential for misinterpretation of dosage ceiling thresholds and the negative repercussions to patients that could follow raised concerns among both physicians and patients. We provide a comprehensive overview of the rationale, early impact, controversies, and potential shortcomings of the CPSBC's practice standard.

Cohort profile: development and characteristics of a retrospective cohort of individuals dispensed prescription opioids for non-cancer pain in British Columbia, Canada

PURPOSE

Prescription opioids (POs) are widely prescribed for chronic non-cancer pain but are associated with several risks and limited long-term benefit. Large, linked data sources are needed to monitor their harmful effects. We developed and characterised a retrospective cohort of people dispensed POs.

PARTICIPANTS

We used a large linked administrative database to create the Opioid Prescribing Evaluation and Research Activities cohort of individuals dispensed POs for non-cancer pain in British Columbia (BC), Canada (1996-2015). We created definitions to categorise episodes of PO use based on a review of the literature (acute, episodic, chronic), developed an algorithm for inferring clinical indication and assessed patterns of PO use across a range of characteristics.

FINDINGS TO DATE

The current cohort includes 1.1 million individuals and 3.4 million PO episodes (estimated to capture 40%-50% of PO use in BC). The majority of episodes were acute (81%), with most prescribed for dental or surgical pain. Chronic use made up 3% of episodes but 88% of morphine equivalents (MEQ). Across the acute to episodic to chronic episode gradient, there was an increasing prevalence of higher potency POs (hydromorphone, oxycodone, fentanyl, morphine), long-acting formulations and chronic pain related indications (eg, back, neck, joint pain). Average daily dose (MEQ) was similar for acute/episodic but higher for chronic episodes. Approximately 7% of the cohort had a chronic episode and chronic pain was the characteristic most strongly associated with chronic PO use. Individuals initiating a chronic episode were also more likely to have higher social/material deprivation and previous experience with a mental health condition or a problem related to alcohol or opioid use. Overall, these findings suggest our episode definitions have face validity and also provide insight into characteristics of people initiating chronic PO therapy.

FUTURE PLANS

The cohort will be refreshed every 2 years. Future analyses will explore the association between POs and adverse outcomes.

Death after emergency department visits for opioid overdose in British Columbia: a retrospective cohort analysis

BACKGROUND

Visits to the emergency department are critical opportunities to engage individuals after an overdose. We sought to estimate and compare the 12-month mortality between persons with visits to the emergency department related to opioid overdose and those with non-overdose-related visits.

METHODS

We conducted a retrospective cohort study using the Provincial Overdose Cohort, which contains data for patients in British Columbia who had an opioid-related overdose between 2015 and 2017, along with a 20% random sample of BC residents for comparison. We examined all nonfatal visits to the emergency department between Jan. 1, 2015, and Dec. 31, 2016, among persons aged 14 to 74 years and compared the 12-month mortality between those with overdose-related visits and those with non-overdose-related visits. We estimated the hazard ratio for death, with adjustment for age, sex, comorbidity and disposition (discharged or left against medical advice).

RESULTS

We included 3593 persons with overdose-related visits and 216 453 with non-overdose-related visits to the emergency department. Those with overdose-related visits were younger, were predominantly male and had more mental health conditions. The 12-month crude mortality probability was 5.4% (95% confidence interval [CI] 4.7%-6.2%) in this group and 1.7% (95% CI 1.6%-1.8%) among those with non-overdose-related visits. After adjustment, for persons who were discharged, the 12-month mortality hazard was 3.5 (95% CI 3.0-4.2) times higher among those with overdose-related visits than those with non-overdose-related visits. For persons who left against medical advice, the mortality hazard was 7.1 (95% CI 4.0-12.5) times higher among those with opioid overdose.

INTERPRETATION

Among persons with overdose-related visits to the emergency department, 12-month mortality was higher than among those with non-overdose-related visits. Overdose-related visits should prompt urgent evidence-based interventions (e.g., take-home naloxone kits, buprenorphine-naloxone induction) to prevent future deaths.

Abuse and Misuse of Pregabalin and Gabapentin: A Systematic Review Update

BACKGROUND

A 2017 systematic review (SR) identified 59 studies examining gabapentinoid (pregabalin and gabapentin) misuse/abuse. Evidence of gabapentinoid misuse/abuse has since grown substantially.

OBJECTIVE

Update previous SR and describe new insights regarding gabapentinoid abuse.

METHODS

A SR of PubMed was conducted to identify studies published from 7/29/2016-8/31/2020. Four searches were performed using the following terms: "gabapentin [MeSH] OR pregabalin [MeSH] OR gabapentinoid" AND one of the following substance misuse/abuse-related terms: "substance-related disorders [MeSH]", "overdose", "abuse", or "misuse". Clinicaltrials.gov and the Cochrane Library database were searched to identify ongoing studies or similar SRs. Reference lists of included studies were reviewed to identify additional literature. All studies with novel data related to pregabalin and/or gabapentin abuse, misuse, or overdose conducted during the study period were included. Articles not written in English, review articles, and animal studies were excluded.

RESULTS

Fifty-five studies were included (29 [52.7%] from North America, 17 [30.9%] Europe, 6 [10.9%] Asia, and 3 [5.5%] Australia). Forty-six observational studies and 10 case reports/series were included (one manuscript included both). Twenty (36.4%) studied gabapentin only, 18 (32.7%) pregabalin only, and 17 (30.9%) both pregabalin/gabapentin. These studies corroborate findings from the previous SR that gabapentinoids are increasingly abused or misused to self-medicate, that gabapentinoids can produce desirable effects alone but are often used concomitantly with other drugs, and that opioid use disorder is the greatest risk factor for gabapentinoid abuse. While the original SR identified the largest studies having been published in Europe, this review identified several more generalisable US studies that have subsequently been conducted. The most concerning finding was increased evidence of associated patient harm, including increased hospital utilisation and opioid-related overdose mortality risk.

CONCLUSION

Evidence suggests that gabapentinoid misuse/abuse represents a growing trend that is causing significant patient harm. Prescribers should exercise appropriate caution with use in high-risk populations and monitor for signs of misuse or abuse.

Pain management with opioids in adults

Given the ubiquitous nature of opioids in the treatment of pain, it is an interesting paradox that this class of medications also represents one of the least understood components of clinical pain medicine. For many years, there has been intense interest in the mechanisms of opioid activity, but this has not resulted in a corresponding increase in convincing clinical data. This review focuses primarily on the evidence surrounding the long-term use of opioids in chronic pain, but discussions of this research are often conflated with the very different data governing acute and cancer-related pain, where evidence of efficacy is clearer. It is therefore important to clarify the evidence-based indications for opioid therapy. There remains very little evidence that opioids improve function or quality of life beyond 3 months in people with chronic pain conditions. In all three patient populations, the development of tolerance, dependence, hyperalgesia and withdrawal are key phenomena that affect the patient experience, and in particular the decision to remain on opioids in the long term. This is a common thread that connects the opioid literature in all of these spheres, and justifies the burgeoning interest in these phenomena in the basic science literature. There is an urgent need to address these negative consequences of opioid use, in order to maximize the therapeutic benefit that opioids can offer.

Risk and protective factors for repeated overdose after opioid overdose survival

BACKGROUND

Nonfatal opioid overdose (OD) is an opportunity to identify patients who may benefit from interventions to reduce repeated overdose (rOD). In this study, we sought to determine risk and protective factors associated with rOD.

METHODS

In this retrospective cohort study of 4,155 patients aged 18-64 who presented to one of 16 emergency departments in a single Western Pennsylvania health system between July 2015 and January 2018 for index opioid overdose (iOD) and survived to discharge, we identified demographic and clinical factors association with rOD within one-year. Relative risk of repeated opioid overdose was estimated using adjusted Cox proportional hazard ratios (aHRs).

RESULTS

14.9 % of patients (95 % CI 13.9-16.1) had a rOD, with 29 % occurring within 30 days from iOD. The adjusted hazard of opioid overdose was increased for male patients (aHR = 1.19; 95 % CI 1.01, 1.41), those with pre-iOD diagnoses of anxiety (aHR = 1.41; 95 % CI1.13, 1.77), depression (aHR = 1.44; 95 % CI 1.17, 1.78), substance use disorders (aHR = 1.30; 95 % CI 1.09, 1.55), and alcohol use disorder (aHR = 1.52; 95 % CI 1.02, 2.25). The hazard was lower for individuals prescribed an opioid in the 90 days prior to iOD (aHR = 0.59; 95 % CI 0.37, 0.97) and those admitted to the hospital for iOD (aHR = 0.56; 95 % CI 0.37, 0.86).

CONCLUSION

We found that, among ED patients who survive an initial OD, mental health and substance use diagnoses are associated with a higher hazard of repeated overdoses whereas opioids prescriptions and admission are associated with lower hazards.

Psychiatry and the Opioid Crisis in Canada

A position statement developed by the Canadian Psychiatric Association's Professional Standards and Practice Committee and approved by the CPA's Board of Directors on April 18, 2019.

Known fentanyl use among clients of harm reduction sites in British Columbia, Canada

BACKGROUND

North America is in the midst of an opioid overdose epidemic and it is commonly suggested that exposure to fentanyl is unknown. Using a provincial survey of harm reduction site clients, we aimed to characterize known and unknown fentanyl use and their correlates among people who use drugs in British Columbia, Canada.

METHODS

We recruited 486 clients who were >18 years old and 316 agreed to provide a urine sample for substance use testing. Reported known fentanyl use was defined as a three-level categorical variable assessing recent (i.e., in the previous three days) fentanyl exposure: (i) known exposure; (ii) unknown exposure; and (iii) no exposure. We also assessed any exposure to fentanyl (Yes vs. No) confirmed by urinalysis. Survey data were summarized using descriptive statistics. Multinomial logistic regression and modified Poisson regression models were built to examine different correlates of exposure to fentanyl.

RESULTS

Median age of the participants was 40 (IQR: 32-49). Out of the 303 eligible participants, 38.7% (117) reported known fentanyl use, 21.7% (66) had unknown fentanyl use, and 39.6% (120) had no recent fentanyl use. In the adjusted multinomial logistic regression model and in comparison with unknown fentanyl use, recent known fentanyl use was significantly associated with self-report of methadone use (aRRR = 3.18), heroin/morphine use (aRRR = 4.40), and crystal meth use (aRRR = 2.95). Moreover, any recent exposure to fentanyl (i.e., positive urine test for fentanyl) was significantly associated with living in urban settings (aPR = 1.49), and self-reporting recent cannabis use (aPR = 0.73), crystal meth (aPR = 1.45), and heroin/morphine use (aPR = 2.48).

CONCLUSION

The landscape of illicit opioid use is changing in BC and more people are using fentanyl knowingly. The increasing prevalence of known fentanyl use is concerning and calls for further investments in public awareness and public policy efforts regarding fentanyl exposure and risks.

Prescribing patterns before and after a non-fatal drug overdose using Tennessee's controlled substance monitoring database linked to hospital discharge data

We performed a statewide evaluation of prescribing patterns of controlled substances (CS) before and after an overdose, using Tennessee's Hospital Discharge Data System and the Controlled Substance Monitoring Database (CSMD). Adults' first non-fatal overdose discharges either from the emergency department (ED) or inpatient (IP) stay occurring between 2013 and 2016 were linked to prescriptions in the CSMD. The difference in the proportion of patients filling a prescription before versus after an overdose was calculated. Included were 49,398 patients with an overdose and a prescription record; most (60.5%) were treated in the ED. Among any drug type overdose the percentage of patients who filled a CS prescription within a year of experiencing an overdose was as follows: opioid analgesics: 59.1%, benzodiazepines: 37.3%, stimulants: 5.0%, muscle relaxants: 3.4%, concurrent opioid-benzodiazepines: 24.0% with the percent difference from before to after similar in both settings. Among patients treated for an opioid overdose, this represented a decrease in opioid analgesics filled by 9.7% (95%CI: -11.2, -8.3) among those treated in the ED, and by 7.1% (95% CI: -8.3, -5.9) among treated inpatients. Among patients treated for a heroin overdose, 12.2% (95%CI: -15.2, -9.3) fewer of those treated in the ED and 8.8% (95%CI: -15.0, -2.7%) fewer of treated inpatients filled a CS prescription in that year. The most common opioid analgesics included hydrocodone and oxycodone. The number of patients filling buprenorphine for treatment increased in the year after overdoses associated with any drug or opioids but decreased among those treated for a heroin overdose.

Policing space in the overdose crisis: A rapid ethnographic study of the impact of law enforcement practices on the effectiveness of overdose prevention sites

North America is in the midst of an overdose crisis. In some of the hardest hit areas of Canada, local responses have included the implementation of low-threshold drug consumption facilities, termed Overdose Prevention Sites (OPS). In Vancouver, Canada the crisis and response occur in an urban terrain that is simultaneously impacted by a housing crisis in which formerly 'undesirable' areas are rapidly gentrifying, leading to demands to more closely police areas at the epicenter of the overdose crisis. We examined the intersection of street-level policing and gentrification and how these practices re/made space in and around OPS in Vancouver's Downtown Eastside neighborhood. Between December 2016 and October 2017, qualitative interviews were conducted with 72 people who use drugs (PWUD) and over 200 h of ethnographic fieldwork were undertaken at OPS and surrounding areas. Data were analyzed thematically and interpreted by drawing on structural vulnerability and elements of social geography. While OPS were established within existing social-spatial practices of PWUD, gentrification strategies and associated police tactics created barriers to OPS services. Participants highlighted how fear of arrest and police engagement necessitated responding to overdoses alone, rather than engaging emergency services. Routine policing near OPS and the enforcement of area restrictions and warrant searches, often deterred participants from accessing particular sites. Further documented was an increase in the number of police present in the neighborhood the week of, and the week proceeding, the disbursement of income assistance cheques. Our findings demonstrate how some law enforcement practices, driven in part by ongoing gentrification efforts and buttressed by multiple forms of criminalization present in the lives of PWUD, limited access to needed overdose-related services. Moving away from place-based policing practices, including those driven by gentrification, will be necessary so as to not undermine the effectiveness of life-saving public health interventions amid an overdose crisis.