Development and characteristics of the Provincial Overdose Cohort in British Columbia, Canada

Opportunities to improve inpatient services and reduce rates of patient-direct discharge among people who use substances

PURPOSE

Patients who use substances (PWUS) report experiencing stigmatizing encounters and undertreatment of pain and withdrawal symptoms that increase the likelihood of patient-directed discharge (PDD). This scoping review examines North American literature to gain insights about how institutional factors intersect with patient experiences and contribute to PDD.

METHODS

A scoping review was conducted using MEDLINE, CINAHL, Scopus, and EMBASE databases. Screening was completed by two reviewers. A data extraction tool developed by the research team was used to collect demographic information and explore patients' experiences and reasons for PDD.

RESULTS

We present four themes related to PDD: i) effective management of pain and withdrawal symptoms, ii) therapeutic alliance with healthcare providers, iii) hospital policies, protocols, and procedures, and iv) recommendations. Notably, all patients in all qualitative studies reported predominant experiences of uncaring, stigmatizing interactions with healthcare providers.

DISCUSSION

Findings suggest that transformations are required at individual and institutional levels. At an individual level, to provide equitable care to all patients, healthcare providers in all practice settings should be competent to effectively and compassionately care for PWUS. At an institutional level, policies need to be re-envisioned to support the implementation of effective practices.

CONCLUSION

Hospitals are faced with the challenges to ensure respectful care environments guided by harm reduction policies that will improve engagement of PWUS in services.

Receipt of Opioid Agonist Treatment in provincial correctional facilities in British Columbia is associated with a reduced hazard of nonfatal overdose in the month following release

BACKGROUND

In many jurisdictions, policies restrict access to Opioid Agonist Treatment (OAT) in correctional facilities. Receipt of OAT during incarceration is associated with reduced risk of fatal overdose after release but little is known about the effect on nonfatal overdose. This study aimed to examine the association between OAT use during incarceration and nonfatal overdose in the 30 days following release.

METHODS AND FINDINGS

Using linked administrative healthcare and corrections data for a random sample of 20% of residents of British Columbia, Canada we examined releases from provincial correctional facilities between January 1, 2015 -December 1, 2018, among adults (aged 18 or older at the time of release) with Opioid Use Disorder. We fit Andersen-Gill models to examine the association between receipt of OAT in custody and the hazard of nonfatal following release. We conducted secondary analyses to examine the association among people continuing treatment initiated prior to their arrest and people who initiated a new episode of OAT in custody separately. We also conducted sex-based subgroup analyses. In this study there were 4,738 releases of 1,535 people with Opioid Use Disorder. In adjusted analysis, receipt of OAT in custody was associated with a reduced hazard of nonfatal overdose (aHR 0.55, 95% CI 0.41, 0.74). This was found for prescriptions continued from community (aHR 0.49, 95%CI 0.36, 0.67) and for episodes of OAT initiated in custody (aHR 0.58, 95%CI 0.41, 0.82). The effect was greater among women than men.

CONCLUSIONS

OAT receipt during incarceration is associated with a reduced hazard of nonfatal overdose after release. Policies to expand access to OAT in correctional facilities, including initiating treatment, may help reduce harms related to nonfatal overdose in the weeks following release. Differences in the effect seen among women and men indicate a need for gender-responsive policies and programming.

Medical training to effectively support patients who use substances across practice settings: a scoping review of recommended competencies

Background

The responsibility for addressing the healthcare needs of PWUS is the responsibility of all physicians. Within the healthcare system, research consistently reveals inequitable experiences in healthcare with people who use substances (PWUS) reporting stigmatization, marginalization, and a lack of compassion.

Objectives

The aim of this scoping review was to find and describe competencies being taught, developed, and fostered within medical education and then to provide recommendations to improve care for this population of patients.

Results

Nineteen articles were included. Recommended knowledge competencies tend to promote understanding neurophysiological changes caused by substances, alongside knowing how to evaluate of 'risky' behaviours. Commonly recommended skills relate to the screening and management of substance use disorders. Recommended attitude competencies include identifying personal bias and establishing a patient-centered culture among practice teams. The disease model of addiction informed all papers, with no acknowledgement of potential beneficial or non-problematic experiences of substance use. To enhance knowledge-type competencies, medical education programs are advised to include addiction specialists as educators and prevent stigmatization through the hidden curriculum.

Conclusion

To reduce experiences of stigmatization and marginalization among patients who use illicit substances and to improve quality of care, knowledge, skills, and attitudes competencies can be more effectively taught in medical education programs.Résumé.

Effect of Risk Mitigation Guidance opioid and stimulant dispensations on mortality and acute care visits during dual public health emergencies: retrospective cohort study

OBJECTIVE

To determine the effect of opioid and stimulant Risk Mitigation Guidance (RMG) dispensations on mortality and acute care visits during the dual public health emergencies of overdose and covid-19.

DESIGN

Population based retrospective cohort study.

SETTING

British Columbia, Canada.

PARTICIPANTS

5882 people with opioid or stimulant use disorder who received RMG prescriptions for opioids (n=5356) and/or stimulants (n=1061) (535 received both) from 27 March 2020 to 31 August 2021.

MAIN OUTCOME MEASURES

All cause and overdose specific mortality and acute care visits in the week after RMG opioid or stimulant dispensation. RMG recipients were matched 1:1 with controls through use of high dimensional propensity score matching. Marginal structural models, executed on weekly time steps, were used to measure the effect of dispensations on outcomes.

RESULTS

RMG opioid dispensations of one day or more were associated with reduced all cause mortality (adjusted hazard ratio 0.39, 95% confidence interval 0.25 to 0.60) and overdose related mortality (0.45, 0.27 to 0.75) in the subsequent week. Dispensations of RMG stimulants (≥1 days) were not significantly associated with reduced all cause mortality (adjusted hazard ratio 0.50, 0.20 to 1.23) or overdose related mortality (0.53, 0.18 to 1.56). The protective effect of RMG opioid dispensations increased with the number of days the medications were dispensed in a given week. People who received four or more days of RMG opioid dispensations had reduced all cause mortality (adjusted hazard ratio 0.09, 0.04 to 0.21) and overdose related mortality (0.11, 0.04 to 0.32) compared with the control group. Opioid RMG dispensations did not significantly modify the odds of all cause or overdose related acute care visits. Dispensations of RMG stimulants were associated with a significant decrease in the odds of acute care visits for any cause but did not affect the odds of overdose related acute care visits.

CONCLUSIONS

RMG opioid dispensations were associated with reduced overdose related and all cause mortality among a sample of people with opioid use disorder. Pharmaceutical alternatives to the illegal drug supply are promising interventions to reduce mortality in people with opioid use disorder.

Database quality assessment in research in paramedicine: a scoping review

BACKGROUND

Research in paramedicine faces challenges in developing research capacity, including access to high-quality data. A variety of unique factors in the paramedic work environment influence data quality. In other fields of healthcare, data quality assessment (DQA) frameworks provide common methods of quality assessment as well as standards of transparent reporting. No similar DQA frameworks exist for paramedicine, and practices related to DQA are sporadically reported. This scoping review aims to describe the range, extent, and nature of DQA practices within research in paramedicine.

METHODS

This review followed a registered and published protocol. In consultation with a professional librarian, a search strategy was developed and applied to MEDLINE (National Library of Medicine), EMBASE (Elsevier), Scopus (Elsevier), and CINAHL (EBSCO) to identify studies published from 2011 through 2021 that assess paramedic data quality as a stated goal. Studies that reported quantitative results of DQA using data that relate primarily to the paramedic practice environment were included. Protocols, commentaries, and similar study types were excluded. Title/abstract screening was conducted by two reviewers; full-text screening was conducted by two, with a third participating to resolve disagreements. Data were extracted using a piloted data-charting form.

RESULTS

Searching yielded 10,105 unique articles. After title and abstract screening, 199 remained for full-text review; 97 were included in the analysis. Included studies varied widely in many characteristics. Majorities were conducted in the United States (51%), assessed data containing between 100 and 9,999 records (61%), or assessed one of three topic areas: data, trauma, or out-of-hospital cardiac arrest (61%). All data-quality domains assessed could be grouped under 5 summary domains: completeness, linkage, accuracy, reliability, and representativeness.

CONCLUSIONS

There are few common standards in terms of variables, domains, methods, or quality thresholds for DQA in paramedic research. Terminology used to describe quality domains varied among included studies and frequently overlapped. The included studies showed no evidence of assessing some domains and emerging topics seen in other areas of healthcare. Research in paramedicine would benefit from a standardized framework for DQA that allows for local variation while establishing common methods, terminology, and reporting standards.

Using a cascade of care framework to identify gaps in access to medications for alcohol use disorder in British Columbia, Canada

BACKGROUND AND AIMS

Despite the significant burden of alcohol use disorder (AUD) and availability of safe and effective medications for AUD (MAUD), population-level estimates of access and engagement in AUD-related care are limited. The aims of this study were to generate a cascade of care for AUD in British Columbia (BC), Canada, and to estimate the impacts of MAUD on health outcomes.

DESIGN

This was a retrospective population-based cohort study using linked administrative health data.

SETTING

British Columbia, Canada, 2015-2019.

PARTICIPANTS

Using a 20% random sample of BC residents, we identified 7231 people with moderate-to-severe alcohol use disorder (PWAUD; overall prevalence = 0.7%).

MEASUREMENTS

We developed a six-stage AUD cascade (from diagnosis to ≥6 months retention in MAUD) among PWAUD. We evaluated trends over time and estimated the impacts of access to MAUD on AUD-related hospitalizations, emergency department visits and death.

FINDINGS

Between 2015 and 2019, linkage to AUD-related care decreased (from 80.4% to 46.5%). However, rates of MAUD initiation (11.4% to 24.1%) and retention for ≥1 (7.0% to 18.2%), ≥3 (1.2% to 4.3%) or ≥6 months (0.2% to 1.6%) increased significantly. In adjusted analyses, access to MAUD was associated with reduced odds of experiencing any AUD-related adverse outcomes, with longer retention in MAUD showing a trend to greater odds reduction: adjusted odds ratio (95% CI) ranging from 0.59 (0.48-0.71) for MAUD retention <1 month to 0.37 (0.21-0.67) for ≥6 months retention.

CONCLUSIONS

Access to medications for alcohol use disorder among people with moderate-to-severe alcohol use disorder in British Colombia, Canada increased between 2015 and 2019; however, initiation and retention remained low. There was a trend between longer retention in medications for alcohol use disorder and greater reductions in the odds of experiencing alcohol use disorder-related adverse outcomes.

Delivery of public health interventions by the ambulance sector: a scoping review

BACKGROUND

With millions of unscheduled patient contacts every year and increasing call outs clustered around the most deprived communities, it is clear the ambulance sector could have a role to play in improving population health. However, the application and value of a public health approach within the ambulance sector has not been comprehensively explored. A scoping review was undertaken to explore the role of the ambulance sector in the delivery of public health interventions and what impact this has on population health and ambulance sector outcomes.

METHODS

A search strategy was developed on MEDLINE and translated to other major medical and health related bibliographic databases (Embase; CINAHL; HMIC; Science and Social Sciences Citation Index; Cochrane Library) to identify literature published since 2000 in OECD countries. Targeted grey literature, reference list, and citation searching was also carried out. Search results were downloaded to Microsoft Excel and screened by three reviewers according to pre-determined inclusion / exclusion criteria. Data from included studies, such as the type of activity noted within the paper, the population involved and the public health approach that was utilised, was extracted from within the paper using a data extraction form and narratively synthesised.

RESULTS

Fifty-two references were included in the final review (37 database searching; 9 reference list searching; 6 grey literature). Included articles were categorised according to the relevant public health domains and subdomains as articulated by the UK Faculty of Public Health: 1. Health improvement domain: Public health education and advice (Health promotion sub-domain) (n=13) Emergency Services personnel providing vaccines (Disease prevention sub-domain) (n=1) 2. Health care public health domain Paramedicine (Service delivery sub-domain) (n=30) Screening tools and referral pathways used by the ambulance sector (Service delivery sub-domain) (n=28) Health intelligence using ambulance sector data (population health management sub-domain) (n=26) Of note, some domains (e.g. health protection) returned nil results.

DISCUSSION

The scoping review demonstrates the breadth of public health related activities in which the ambulance sector is involved. However, an overemphasis on demand management outcomes precludes definitive conclusions on the impact of ambulance sector-led public health initiatives on public health outcomes. Future evaluations of public health initiatives should incorporate wider health system perspectives beyond the immediately apparent remit of the ambulance sector.

Association between toxic drug events and encephalopathy in British Columbia, Canada: a cross-sectional analysis

BACKGROUND

Encephalopathy can occur from a non-fatal toxic drug event (overdose) which results in a partial or complete loss of oxygen to the brain, or due to long-term substance use issues. It can be categorized as a non-traumatic acquired brain injury or toxic encephalopathy. In the context of the drug toxicity crisis in British Columbia (BC), Canada, measuring the co-occurrence of encephalopathy and drug toxicity is challenging due to lack of standardized screening. We aimed to estimate the prevalence of encephalopathy among people who experienced a toxic drug event and examine the association between toxic drug events and encephalopathy.

METHODS

Using a 20% random sample of BC residents from administrative health data, we conducted a cross-sectional analysis. Toxic drug events were identified using the BC Provincial Overdose Cohort definition and encephalopathy was identified using ICD codes from hospitalization, emergency department, and primary care records between January 1st 2015 and December 31st 2019. Unadjusted and adjusted log-binomial regression models were employed to estimate the risk of encephalopathy among people who had a toxic drug event compared to people who did not experience a toxic drug event.

RESULTS

Among people with encephalopathy, 14.6% (n = 54) had one or more drug toxicity events between 2015 and 2019. After adjusting for sex, age, and mental illness, people who experienced drug toxicity were 15.3 times (95% CI = 11.3, 20.7) more likely to have encephalopathy compared to people who did not experience a drug toxicity event. People who were 40 years and older, male, and had a mental illness were at increased risk of encephalopathy.

CONCLUSIONS

There is a need for collaboration between community members, health care providers, and key stakeholders to develop a standardized approach to define, screen, and detect neurocognitive injury related to drug toxicity.

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.

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.

Stimulant use disorder diagnosis and opioid agonist treatment dispensation following release from prison: a cohort study

BACKGROUND

Concurrent opioid and stimulant use is on the rise in North America. This increasing trend of use has been observed in the general population, and among people released from prison in British Columbia (BC), who face an elevated risk of overdose post-release. Opioid agonist treatment is an effective treatment for opioid use disorder and reduces risk of overdose mortality. In the context of rising concurrent stimulant use among people with opioid use disorder, this study aims to investigate the impact of stimulant use disorder on opioid agonist treatment dispensation following release from prison in BC.

METHODS

Linked health and corrections records were retrieved for releases between January 1^st 2015 and December 29^th 2018 (N = 13,380). Hospital and primary-care administrative health records were used to identify opioid and stimulant use disorder and mental illness. Age, sex, and health region were derived from BC's Client Roster. Incarceration data were retrieved from provincial prison records. Opioid agonist treatment data was retrieved from BC's provincial drug dispensation database. A generalized estimating equation produced estimates for the relationship of stimulant use disorder and opioid agonist treatment dispensation within two days post-release.

RESULTS

Cases of release among people with an opioid use disorder were identified (N = 13,380). Approximately 25% (N = 3,328) of releases ended in opioid agonist treatment dispensation within two days post-release. A statistically significant interaction of stimulant use disorder and mental illness was identified. Stratified odds ratios (ORs) found that in the presence of mental illness, stimulant use disorder was associated with lower odds of obtaining OAT [(OR) = 0.73, 95% confidence interval (CI) = 0.64-0.84)] while in the absence of mental illness, this relationship did not hold [OR = 0.89, 95% CI = 0.70-1.13].

CONCLUSIONS

People with mental illness and stimulant use disorder diagnoses have a lower odds of being dispensed agonist treatment post-release compared to people with mental illness alone. There is a critical need to scale up and adapt opioid agonist treatment and ancillary harm reduction, and treatment services to reach people released from prison who have concurrent stimulant use disorder and mental illness diagnoses.

Self-injecting non-prescribed substances into vascular access devices: a case study of one health system's ongoing journey from clinical concern to practice and policy response

BACKGROUND

Overdose-associated deaths and morbidity related to substance use is a global public health emergency with devastating social and economic costs. Complications of substance use are most pronounced among people who inject drugs (PWID), particularly infections, resulting in increased risk of hospitalization. PWID often require intravenous access for medical treatments such as antibiotics; however, vascular access may be limited due to the impacts of long-term self-venipuncture. While vascular access devices including peripherally inserted central catheters (PICCs) allow reliable and sustained routes of administration for indicated therapies, the use of PICCs among PWID presents unique challenges. The incidence and risks associated with self-injecting non-prescribed substances into vascular access devices (SIVAD) is one such concern for which there is limited evidence and absence of formal practice guidance.

CASE PRESENTATION

We report the experience of a multidisciplinary team at a health organization in Vancouver, Canada, working to characterize the incidence, patient and healthcare provider perspectives, and overall impact of SIVAD. The case study of SIVAD begins with a patient's perspective, including patient rationale for SIVAD, understanding of risks and the varying responses given by healthcare providers following disclosure of SIVAD. Using the limited literature available on the subject, we summarize the intersection of SIVAD and substance use and outline known and anticipated health risks. The case study is further contextualized by experience from a Vancouver in-hospital Overdose Prevention Site (OPS), where 37% of all individual visits involve SIVAD. The case study concludes by describing the systematic process by which local clinical guidance for SIVAD harm reduction was developed with stakeholder engagement, medical ethics consultation, expert consensus guideline development and implementation with staff education and planned research evaluation.

CONCLUSION

SIVAD is encountered with enough frequency in an urban healthcare setting in Vancouver, Canada, to warrant an organizational approach. This case study aims to enhance appreciation of SIVAD as a common and complex clinical issue with anticipated health risks. The authors conclude that using a harm reduction lens for SIVAD policy and research can provide benefit to clinicians and patients by offering a clear and a consistent healthcare response to this common issue.

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.

Association of Opioid and Stimulant Use Disorder Diagnoses With Fatal and Nonfatal Overdose Among People With a History of Incarceration

IMPORTANCE

Studies have suggested a rise in opioid- and stimulant-involved overdoses in recent years in North America. This risk may be acute for individuals who have had contact with the criminal justice system, who are particularly vulnerable to overdose risk.

OBJECTIVE

To examine the association of opioid and/or stimulant use disorder diagnoses with overdose (fatal and nonfatal) among people with histories of incarceration.

DESIGN, SETTING, AND PARTICIPANTS

In this cohort study, population-based health and corrections data were retrieved from the British Columbia Provincial Overdose Cohort, which contains a 20% random sample of residents of British Columbia. The analysis included all people in the 20% random sample who had a history of incarceration between January 1, 2010, and December 31, 2014. Outcomes were derived from 5-years of follow-up data (January 1, 2015, to December 31, 2019). Statistical analysis took place from January 2022 to June 2022.

EXPOSURES

Substance use disorder diagnosis type (ie, opioid use disorder, stimulant use disorder, both, or neither), sociodemographic, health, and incarceration characteristics.

MAIN OUTCOMES AND MEASURES

Hazard ratios (HRs) are reported from an Andersen-Gill model for recurrent nonfatal overdose events and from a Fine and Gray competing risk model for fatal overdose events.

RESULTS

The study identified 6816 people (5980 male [87.7%]; 2820 aged <30 years [41.4%]) with histories of incarceration. Of these, 293 (4.3%) had opioid use disorder only, 395 (6.8%) had stimulant use disorder only, and 281 (4.1%) had both diagnoses. During follow-up, 1655 people experienced 4026 overdoses including 3781 (93.9%) nonfatal overdoses, and 245 (6.1%) fatal overdoses. In adjusted analyses, the hazard of both fatal (HR, 2.39; 95% CI, 1.48-3.86) and nonfatal (HR, 2.45; 95% CI, 1.94-3.11) overdose was highest in the group with both opioid and stimulant use disorder diagnoses.

CONCLUSIONS AND RELEVANCE

This cohort study of people with a history of incarceration found an elevated hazard of fatal and nonfatal overdose among people with both opioid and stimulant use disorder diagnoses. This study suggests an urgent need to address the service needs of individuals who have had contact with the criminal justice system and who co-use opioids and stimulants.

Using linked data to identify pathways of reporting overdose events in British Columbia, 2015-2017

Introduction

Overdose events related to illicit opioids and other substances are a public health crisis in Canada. The BC Provincial Overdose Cohort is a collection of linked datasets identifying drug-related toxicity events, including death, ambulance, emergency room, hospital, and physician records. The datasets were brought together to understand factors associated with drug-related overdose and can also provide information on pathways of care among people who experience an overdose.

Objectives

To describe pathways of recorded healthcare use for overdose events in British Columbia, Canada and discrepancies between data sources.

Methods

Using the BC Provincial Overdose Cohort spanning 2015 to 2017, we examined pathways of recorded health care use for overdose through the framework of an injury reporting pyramid. We also explored differences in event capture between linked datasets.

Results

In the cohort, a total of 34,113 fatal and non-fatal overdose events were identified. A total of 3,056 people died of overdose. Nearly 80% of these deaths occurred among those with no contact with the healthcare system. The majority of events with healthcare records included contact with EHS services (72%), while 39% were seen in the ED and only 7% were hospitalized. Pathways of care from EHS services to ED and hospitalization were generally observed. However, not all ED visits had an associated EHS record and some hospitalizations following an ED visit were for other health issues.

Conclusions

These findings emphasize the importance of accessing timely healthcare for people experiencing overdose. These findings can be applied to understanding pathways of care for people who experience overdose events and estimating the total burden of healthcare-attended overdose events.

Highlights

In British Columbia, Canada:Multiple sources of linked administrative health data were leveraged to understand recorded healthcare use among people with fatal and non-fatal overdose eventsThe majority of fatal overdose events occurred with no contact with the healthcare system and only appear in mortality dataMany non-fatal overdose events were captured in data from emergency health services, emergency departments, and hospital recordsAccessing timely healthcare services is critical for people experiencing overdose.

Alcohol use in adolescence as a risk factor for overdose in the 1986 Northern Finland Birth Cohort Study

Background

Overdoses and poisonings are among the most common causes of death in young adults. Adolescent problem drinking has been associated with psychiatric morbidity in young adulthood as well as with elevated risk for suicide attempts. There is limited knowledge on adolescent alcohol use as a risk factor for alcohol and/or drug overdoses in later life.

Methods

Here, data from The Northern Finland Birth Cohort 1986 study with a follow-up from adolescence to early adulthood were used to assess the associations between adolescent alcohol use and subsequent alcohol or drug overdose. Three predictors were used: age of first intoxication, self-reported alcohol tolerance and frequency of alcohol intoxication in adolescence. ICD-10-coded overdose diagnoses were obtained from nationwide registers. Use of illicit drugs or misuse of medication, Youth Self Report total score, family structure and mother’s education in adolescence were used as covariates.

Results

In multivariate analyses, early age of first alcohol intoxication [hazard ratios (HR) 4.5, 95% confidence intervals (CI) 2.2–9.2, P < 0.001], high alcohol tolerance (HR 3.1, 95% CI 1.6–6.0, P = 0.001) and frequent alcohol intoxication (HR 1.9, 95% CI 1.0–3.4, P = 0.035) all associated with the risk of overdoses. Early age of first intoxication (HR 5.2, 95% CI 1.9–14.7, P = 0.002) and high alcohol tolerance (HR 4.4, 95% CI 1.7–11.5, P = 0.002) also associated with intentional overdoses.

Conclusions

Alcohol use in adolescence associated prospectively with increased risk of overdose in later life. Early age of first intoxication, high alcohol tolerance and frequent alcohol intoxication are all predictors of overdoses.

Analysis of community deaths during the catastrophic 2021 heat dome: Early evidence to inform the public health response during subsequent events in greater Vancouver, Canada

BACKGROUND

British Columbia, Canada, was impacted by a record-setting heat dome in early summer 2021. Most households in greater Vancouver do not have air conditioning, and there was a 440% increase in community deaths during the event. Readily available data were analyzed to inform modifications to the public health response during subsequent events in summer 2021 and to guide further research.

METHODS

The 434 community deaths from 27 June through 02 July 2021 (heat dome deaths) were compared with all 1,367 community deaths that occurred in the same region from 19 June through 09 July of 2013-2020 (typical weather deaths). Conditional logistic regression was used to examine the effects of age, sex, neighborhood deprivation, and the surrounding environment. Data available from homes with and without air conditioning were also used to illustrate the indoor temperatures differences.

RESULTS

A combined index of material and social deprivation was most predictive of heat dome risk, with an adjusted odds ratio of 2.88 [1.85, 4.49] for the most deprived category. Heat dome deaths also had lower greenness within 100 m than typical weather deaths. Indoor temperatures in one illustrative home without air conditioning ranged between 30°C and 40°C.

CONCLUSIONS

Risk of death during the heat dome was associated with deprivation, lower neighborhood greenness, older age, and sex. High indoor temperatures likely played an important role. Public health response should focus on highly deprived neighborhoods with low air conditioning prevalence during extreme heat events. Promotion of urban greenspace must continue as the climate changes.

Prevalence of co-occurring mental illness and substance use disorder and association with overdose: a linked data cohort study among residents of British Columbia, Canada

AIMS

To estimate the treated prevalence of mental illness, substance use disorder (SUD) and dual diagnosis and the association between dual diagnosis and fatal and non-fatal overdose among residents of British Columbia (BC), Canada.

DESIGN

A retrospective cohort study using linked health, income assistance, corrections and death records.

SETTING

British Columbia (BC), Canada.

PARTICIPANTS

A total of 921 346 BC residents (455 549 males and 465 797 females) aged 10 years and older.

MEASUREMENTS

Hospital and primary-care administrative data were used to identify a history of mental illness only, SUD only, dual diagnosis or no history of SUD or mental illness (2010-14) and overdoses resulting in medical care (2015-17). We calculated crude incidence rates of non-fatal and fatal overdose by dual diagnosis history. Andersen-Gill and competing risks regression were used to examine the association between dual diagnosis and non-fatal and fatal overdose, respectively, adjusting for age, sex, comorbidities, incarceration history, social assistance, history of prescription opioid and benzodiazepine dispensing and region of residence.

FINDINGS

Of the 921 346 people in the cohort, 176 780 (19.2%), 6147 (0.7%) and 15 269 (1.7%) had a history of mental illness only, SUD only and dual diagnosis, respectively; 4696 (0.5%) people experienced 688 fatal and 6938 non-fatal overdoses. In multivariable analyses, mental illness only, SUD only and dual diagnosis were associated with increased rate of non-fatal [hazard ratio (HR) = 1.8, 95% confidence interval (CI) = 1.6-2.1; HR = 9.0, 95% CI = 7.0-11.5, HR = 8.7, 95% CI = 6.9-10.9, respectively] and fatal overdose (HR = 1.6, 95% CI = 1.3-2.0, HR = 4.3, 95% CI = 2.8-6.5, HR = 4.1, 95% CI = 2.8-6.0, respectively) compared with no history.

CONCLUSIONS

In a large sample of residents of British Columbia (Canada), approximately one in five people had sought care for a substance use disorder or mental illness in the past 5 years. The rate of overdose was elevated in people with a mental illness alone, higher again in people with a substance use disorder alone and highest in people with a dual diagnosis. The adjusted hazard rates were similar for people with substance use disorder only and people with a dual diagnosis.

Risk of cardiovascular diseases in relation to substance use disorders

BACKGROUND

Substance use disorder (SUD) has become increasingly prevalent worldwide, this study investigated the associations of SUD and alcohol, cannabis, opioid, or stimulant use disorder with cardiovascular disease (CVD) and 11 major CVD subtypes.

METHODS

This study was based on a 20% random sample of residents in British Columbia, Canada, who were aged 18 - 80 years at baseline on January 1, 2015. Using linked administrative health data during 2010 - 2014, we identified people with various SUDs and prevalent CVDs at baseline, and examined the cross-sectional associations between SUDs and CVDs. After excluding people with CVDs at baseline, we followed the cohort for 4 years to identify people who developed incident CVDs, and examined the longitudinal associations between SUDs and CVDs.

RESULTS

The cross-sectional analysis at baseline included 778,771 people (mean age 45 years, 50% male), 13,279 (1.7%) had SUD, and 41,573 (5.3%) had prevalent CVD. After adjusting for covariates, people with SUD were 2.7 (95% confidence interval [CI], 2.5 - 2.8) times more likely than people without SUD to have prevalent CVD. The longitudinal analysis included 617,863 people, 17,360 (2.8%) developed incident CVD during the follow-up period. After adjusting for covariates, people with SUD were 1.7 (95% CI, 1.6 - 1.9) times more likely than people without SUD to develop incident CVD. The cross-sectional and longitudinal associations were more pronounced for people with opioid or stimulant use disorder.

CONCLUSIONS

People with SUD are more likely to have prevalent CVD and develop incident CVD compared with people without SUD.

Use of community healthcare and overdose in the 30 days following release from provincial correctional facilities in British Columbia

BACKGROUND

Interruptions in healthcare services contribute to an elevated risk of overdose in the weeks following release from incarceration. This study examined the association of use of community healthcare with nonfatal and fatal overdose in the 30 days following release.

METHODS

We conducted a retrospective cohort study using linked administrative data from a random sample of 20% of the population of British Columbia. We examined releases from provincial correctional facilities between January 1, 2015-December 1, 2018. We fit multivariate Andersen-Gill models to examine nonfatal overdoses after release from incarceration and applied Standard Cox regression for analyses of fatal overdoses.

RESULTS

There were a combined 16,809 releases of 6721 people in this study. At least one overdose occurred in 2.8% of releases. A community healthcare visit preceded the first nonfatal overdose in 86.4% of releases with a nonfatal overdose event. Only 48.4% of people who had a fatal overdose used community healthcare. In adjusted analysis, people who had used community healthcare had a higher hazard of healthcare-attended nonfatal overdose (aHR 2.83 95% CI 2.13, 3.78) and lower hazard of fatal overdose (aHR 0.58, 95%CI 0.28, 1.19).

CONCLUSIONS

Community healthcare visits after release from custody may be an important opportunity to provide overdose prevention and harm reduction supports. Policies and resourcing are needed to facilitate better connection to primary healthcare during the transition to community. Providers in community should be equipped to offer care to people who have recently experienced incarceration in a way that is accessible, acceptable and trauma-informed.

Fatal overdoses after release from prison in British Columbia: a retrospective data linkage study

BACKGROUND

People recently released from prison are at increased risk of preventable death; however, the impact of the current overdose epidemic on this population is unknown. We aimed to document the incidence and identify risk factors for fatal overdose after release from provincial prisons in British Columbia.

METHODS

We conducted a retrospective, population-based, open cohort study of adults released from prisons in BC, using linked administrative data. Within a random 20% sample of the BC population, we linked provincial health and correctional records from 2010 to 2017 for people aged 23 years or older as of Jan. 1, 2015, who were released from provincial prisons at least once from 2015 to 2017. We identified exposures that occurred from 2010 to 2017 and deaths from 2015 to 2017. We calculated the piecewise incidence of overdose-related and all-cause deaths after release from prison. We used multivariable, mixed-effects Cox regression to identify predictors of all-cause death and death from overdose.

RESULTS

Among 6106 adults released from prison from 2015 to 2017 and followed in the community for a median of 1.6 (interquartile range 0.9-2.3) years, 154 (2.5%) died, 108 (1.8%) from overdose. The incidence of all-cause death was 16.1 (95% confidence interval [CI] 13.7-18.8) per 1000 person-years. The incidence of overdose deaths was 11.2 (95% CI 9.2-13.5) per 1000 person-years, but 38.8 (95% CI 3.2-22.6) in the first 2 weeks after release from prison. After adjustment for covariates, the hazard of overdose death was 4 times higher among those who had been dispensed opioids for pain.

INTERPRETATION

People released from prisons in BC are at markedly increased risk of overdose death. Overdose prevention must go beyond provision of opioid agonist treatment and naloxone on release to address systemic social and health inequities that increase the risk of premature death.

Big data and predictive modelling for the opioid crisis: existing research and future potential

A need exists to accurately estimate overdose risk and improve understanding of how to deliver treatments and interventions in people with opioid use disorder in a way that reduces such risk. We consider opportunities for predictive analytics and routinely collected administrative data to evaluate how overdose could be reduced among people with opioid use disorder. Specifically, we summarise global trends in opioid use and overdoses; describe the use of big data in research into opioid overdose; consider the potential for predictive modelling, including machine learning, for prevention and monitoring of opioid overdoses; and outline the challenges and risks relating to the use of big data and machine learning in reducing harms that are related to opioid use. Future research for improving the coverage and provision of existing interventions, treatments, and resources for opioid use disorder requires collaboration of multiple agencies. Predictive modelling could transport the concept of stratified medicine to public health through novel methods, such as predictive modelling and emulated trials for evaluating diagnoses and prognoses of opioid use disorder, predicting treatment response, and providing targeted treatment recommendations.

Risk of overdose-related death for people with a history of incarceration

BACKGROUND AND AIMS

Reported associations between previous incarceration and the risk of overdose-related death are substantially heterogeneous, and previous studies are limited by an inability to control for confounding factors in risk assessment. This study investigated the associations of overdose-related death with previous incarceration and the number or cumulative duration of previous incarcerations, and individual or neighborhood characteristics that may potentially modify the associations.

DESIGN AND SETTING

A cohort study using a 20% random sample of residents in British Columbia, Canada.

PARTICIPANTS

A total of 765 690 people aged 23 years or older at baseline as of 1 January 2015. Mean age was 50 years; 49% were males.

MEASUREMENTS

Previous incarcerations that occurred during the 5-year exposure period (January 2010 to December 2014) were identified using provincial incarceration records. Overdose-related deaths that occurred during the 3-year follow-up period (January 2015 to December 2017) were identified using linked administrative health data. Baseline individual and neighborhood characteristics were retrieved from the provincial health insurance data.

FINDINGS

In the cohort, 5743 people had an incarceration history during the exposure period, and 634 people died from drug overdose during the follow-up period. The mortality rate was 897 and 22 per 100 000 person-years for people who did and did not have an incarceration history, respectively. After adjusting for baseline individual and neighborhood characteristics (without any interaction term), people who had an incarceration history were 4.04 times (95% confidence interval 3.23-5.06) more likely to die from drug overdose compared with people without an incarceration history. The association was stronger for females, people without diagnoses of substance use disorder and people without dispensation of opioids for pain or benzodiazepines (P < 0.001 for each interaction term). There was no discernible linear trend between the number or cumulative duration of previous incarcerations and the risk of overdose-related death.

CONCLUSIONS

Previous incarceration appears to be a major risk factor for overdose-related death.

Periods of altered risk for non-fatal drug overdose: a self-controlled case series

BACKGROUND

Being recently released from prison or discharged from hospital, or being dispensed opioids, benzodiazepines, or antipsychotics have been associated with an increased risk of fatal drug overdose. This study aimed to examine the association between these periods and non-fatal drug overdose using a within-person design.

METHODS

In this self-controlled case series, we used data from the provincial health insurance client roster to identify a 20% random sample of residents (aged ≥10 years) in British Columbia, Canada between Jan 1, 2015, and Dec 31, 2017 (n=921 346). Individuals aged younger than 10 years as of Jan 1, 2015, or who did not have their sex recorded in the client roster were excluded. We used linked provincial health and correctional records to identify a cohort of individuals who had a non-fatal overdose resulting in medical care during this time period, and key exposures, including periods of incarceration, admission to hospital, emergency department care, and supply of medications for opioid use disorder (MOUD), opioids for pain (unrelated to MOUD), benzodiazepines, and antipsychotics. Using a self-controlled case series, we examined the association between the time periods during and after each of these exposures and the incidence of non-fatal overdose with case-only, conditional Poisson regression analysis. Sensitivity analyses included recurrent overdoses and pre-exposure risk periods.

FINDINGS

We identified 4149 individuals who had a non-fatal overdose in 2015-17. Compared with unexposed periods (ie, all follow-up time that was not part of a designated risk period for each exposure), the incidence of non-fatal overdose was higher on the day of admission to prison (adjusted incidence rate ratio [aIRR] 2·76 [95% CI 1·51-5·04]), at 1-2 weeks (2·92 [2·37-3·61]), and 3-4 weeks (1·34 [1·01-1·78]) after release from prison, 1-2 weeks after discharge from hospital (1·35 [1·11-1·63]), when being dispensed opioids for pain (after ≥4 weeks) or benzodiazepines (entire use period), and from 3 weeks after discontinuing antipsychotics. The incidence of non-fatal overdose was reduced during use of MOUD (aIRRs ranging from 0·33 [0·26-0·42] to 0·41 [0·25-0·67]) and when in prison (0·12 [0·08-0·19]).

INTERPRETATION

Expanding access to and increasing support for stable and long-term medication for the management of opioid use disorder, improving continuity of care when transitioning between service systems, and ensuring safe prescribing and medication monitoring processes for medications that reduce respiratory function (eg, benzodiazepines) could decrease the incidence of non-fatal overdose.

FUNDING

Murdoch Children's Research Institute and National Health and Medical Research Council.

Comparing mortality and healthcare utilization in the year following a paramedic-attended non-fatal overdose among people who were and were not transported to hospital: A prospective cohort study using linked administrative health data

BACKGROUND

As the overdose emergency continues in British Columbia (BC), paramedic-attended overdoses are increasing, as is the proportion of people not transported to hospital following an overdose. This study investigated risk of death and subsequent healthcare utilization for people who were and were not transported to hospital after a paramedic-attended non-fatal overdose.

METHODS

Using a linked administrative health data set which includes all overdoses that come into contact with health services in BC, we conducted a prospective cohort study of people who experienced a paramedic-attended non-fatal overdose between 2015 and 2016. People were followed for 365 days after the index event. The primary outcomes assessed were all-cause mortality and overdose-related death. Additionally, we examined healthcare utilization after the index event.

RESULTS

In this study, 8659 (84%) people were transported and 1644 (16%) were not transported to hospital at the index overdose event. There were 279 overdose deaths (2.7% of people, 59.4% of deaths) during follow-up. There was no significant difference in risk of overdose-related death, though people not transported had higher odds of a subsequent non-fatal overdose event captured in emergency department and outpatient records within 90 days. People transported to hospital had higher odds of using hospital and outpatient services for any reason within 365 days.

CONCLUSIONS

Transport to hospital after a non-fatal overdose is an opportunity to provide care for underlying and chronic conditions. There is a need to better understand factors that contribute to non-transport, particularly among people aged 20-59 and people without chronic conditions.

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.

Emergency Department-initiated Interventions for Patients With Opioid Use Disorder: A Systematic Review

OBJECTIVES

The opioid crisis has risen dramatically in North America in the new millennium, due to both illegal and prescription opioid use. While emergency departments (EDs) represent a potentially strategic setting for interventions to reduce harm from opioid use disorder (OUD), the absence of a recent synthesis of literature limits implementation and scalability. To fill this gap, we conducted a systematic review of the literature on interventions targeting OUDs initiated in EDs.

METHODS

Using an explicit search strategy (PROSPERO), the MEDLINE, CINAHL Complete, EMBASE, and EBM reviews databases were searched from 1980 to October 4, 2019. The gray literature was explored using Google Scholar. Study characteristics were abstracted independently. The methodologic quality and risk of bias were assessed.

RESULTS

Twelve of 2,270 studies met the inclusion criteria (two of high quality). In addition to the heterogeneity of the outcome measures used (retention in treatment, opioid consumption, and overdose), brief intervention and buprenorphine initiation (six of 12 studies) were the most documented with mixed effects for the former and positive short-term and confined to single ED sites effects for the latter.

CONCLUSION

Emergency departments can be an appropriate setting for initiating opioid agonist treatment, but to be sustained, it likely needs to be coupled with community-based follow-up and support to ensure longer-term retention. The scarcity of high-quality evidence on OUD interventions initiated in emergency settings highlights the need for future research.

Individual and county-level variation in outcomes following non-fatal opioid-involved overdose

BACKGROUND

A lack of large-scale, individually linked data often has impeded efforts to disentangle individual-level variability in outcomes from area-level variability in studies of many diseases and conditions. This study investigated individual and county-level variability in outcomes following non-fatal overdose in a state-wide cohort of opioid overdose patients.

METHODS

Participants were 24 031 patients treated by emergency medical services or an emergency department for opioid-involved overdose in Indiana between 2014 and 2017. Outcomes included repeat non-fatal overdose, fatal overdose and death. County-level predictors included sociodemographic, socioeconomic and treatment availability indicators. Individual-level predictors included age, race, sex and repeat non-fatal opioid-involved overdose. Multilevel models examined outcomes following non-fatal overdose as a function of patient and county characteristics.

RESULTS

10.9% (n=2612) of patients had a repeat non-fatal overdose, 2.4% (n=580) died of drug overdose and 9.2% (n=2217) died overall. Patients with a repeat overdose were over three times more likely to die of drug-related causes (OR=3.68, 99.9% CI 2.62 to 5.17, p<0.001). County-level effects were limited primarily to treatment availability indicators. Higher rates of buprenorphine treatment providers were associated with lower rates of mortality (OR=0.82, 95% CI 0.68 to 0.97, p=0.024), but the opposite trend was found for naltrexone treatment providers (OR=1.20, 95% CI 1.03 to 1.39, p=0.021). Cross-level interactions showed higher rates of Black deaths relative to White deaths in counties with high rates of naltrexone providers (OR=1.73, 95% CI 1.09 to 2.73, p=0.019).

CONCLUSION

Although patient-level differences account for most variability in opioid-related outcomes, treatment availability may contribute to county-level differences, necessitating multifaceted approaches for the treatment and prevention of opioid abuse.

Comparing the predictive capability of self-report and medically-verified non-fatal overdose in adults released from prison: A prospective data linkage study

BACKGROUND

Self-reported non-fatal overdose (NFOD) is a predictor of future overdose and is often used to target overdose prevention for people released from prison. However, the level of agreement between self-reported and medically-verified NFOD history remains unknown. This study aimed to determine the agreement between, and predictive value of, self-reported and medically-verified history of NFOD in people recently released from prison.

METHODS

Pre-release baseline survey data from 1307 adults in prison surveyed from 2008 to 2010 in Queensland, Australia were linked to ambulance, emergency department, and hospital records. We compared the agreement of self-reported NFOD history in the baseline survey and medically-verified NFOD ascertained through linked medical data. Unadjusted and adjusted regression models were used to determine the association between self-reported and medically verified NFOD history and medically-verified NFOD after release from prison.

RESULTS

224 (19 %) participants self-reported NFOD history only, 75 (5 %) had medically-verified NFOD history only, and 56 (4 %) both self-reported and had medically-verified NFOD history. Compared to those with no NFOD history, those who self-reported and had a medical history of NFOD (adjusted hazard ratio (AHR) 6.1, 95 %CI 3.1-11.9), those with a medical history only (AHR 3.4, 95 %CI 1.7-7.0), and those who self-reported only (AHR 1.8, 95 %CI 1.0-3.5) were at increased risk of medically-verified NFOD after release from prison.

CONCLUSIONS

Relying on self-report of NFOD is likely to miss people at increased risk of future NFOD, many of whom could be identified through medical records. Wherever possible, data related to NFOD should be triangulated from multiple sources.