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.

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.

Exploring the contextual risk factors and characteristics of individuals who died from the acute toxic effects of opioids and other illegal substances: listening to the coroner and medical examiner voice.

Introduction: Substance-related acute toxicity deaths continue to be a serious public health concern in Canada. This study explored coroner and medical examiner (C/ME)perspectives of contextual risk factors and characteristics associated with deaths from acute toxic effects of opioids and other illegal substances in Canada.

Methods: In-depth interviews were conducted with 36 C/MEs in eight provinces and territories between December 2017 and February 2018.

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.

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.

Modelling the combined impact of interventions in averting deaths during a synthetic-opioid overdose epidemic.

Background And Aims: The province of British Columbia (BC) Canada has experienced a rapid increase in illicit drug overdoses and deaths during the last 4 years, with a provincial emergency declared in April 2016. These deaths have been driven primarily by the introduction of synthetic opioids into the illicit opioid supply. This study aimed to measure the combined impact of large-scale opioid overdose interventions implemented in BC between April 2016 and December 2017 on the number of deaths averted.

An evaluation of Take Home Naloxone program implementation in British Columbian correctional facilities.

Purpose: To understand how the Take Home Naloxone (THN) program is implemented in two pilot correctional facilities in British Columbia (BC), Canada, in order to identify areas for program improvement and inform the expansion of the program to other Canadian correctional facilities The paper aims to discuss these issues.

Design/methodology/approach: Two focus groups and one interview were conducted with healthcare staff at two pilot correctional facilities. Sessions were audio recorded, transcribed verbatim and divergent and convergent experiences within and between the facilities were explored in an iterative process.

Correlates of seeking emergency medical help in the event of an overdose in British Columbia, Canada: Findings from the Take Home Naloxone program.

Background: British Columbia (BC), Canada, is experiencing an unprecedented number of opioid overdoses mainly due to the contamination of illicit drugs with fentanyl and its analogues. Reluctance to seek emergency medical help (i.e.

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

Introduction: British Columbia (BC), Canada declared a public health emergency in April 2016 for opioid overdose. Comprehensive data was needed to identify risk factors, inform interventions, and evaluate response actions. We describe the development of an overdose cohort, including linkage strategy, case definitions, and data governance model, and present the resulting characteristics, including data linkage yields and case overlap among data sources.

Effect of opioid-substitution therapy and mental health counseling on HIV risk among hepatitis C-infected individuals.

Background: Understanding differences in HIV incidence among people living with hepatitis C virus (HCV) can help inform strategies to prevent HIV infection. We estimated the time to HIV diagnosis among HCV-positive individuals and evaluated factors that could affect HIV-infection risk in this population.

Patients And Methods: The British Columbia Hepatitis Testers Cohort includes all BC residents (~1.

Identifying injection drug use and estimating population size of people who inject drugs using healthcare administrative datasets.

Background: Large linked healthcare administrative datasets could be used to monitor programs providing prevention and treatment services to people who inject drugs (PWID). However, diagnostic codes in administrative datasets do not differentiate non-injection from injection drug use (IDU). We validated algorithms based on diagnostic codes and prescription records representing IDU in administrative datasets against interview-based IDU data.

A syndemic approach to assess the effect of substance use and social disparities on the evolution of HIV/HCV infections in British Columbia.

Background: Co-occurrence of social conditions and infections may affect HIV/HCV disease risk and progression. We examined the changes in relationship of these social conditions and infections on HIV and hepatitis C virus (HCV) infections over time in British Columbia during 1990-2013.

Methods: The BC Hepatitis Testers Cohort (BC-HTC) includes ~1.

Late hepatitis B and C diagnosis in relation to disease decompensation and hepatocellular carcinoma development.

Background & Aims: We measured the timing of hepatitis B virus (HBV) and hepatitis C virus (HCV) diagnoses relative to the detection of decompensated cirrhosis (DC) and hepatocellular carcinoma (HCC) as an indicator of late hepatitis diagnosis.

Methods: HBV and HCV diagnoses were defined relative to the diagnosis of DC or HCC such that HBV/HCV diagnoses within two years prior, at the time of or after HCC or DC diagnosis were considered late. We performed multivariable logistic regression to assess factors associated with late HBV/HCV diagnoses among those with DC or HCC.

Long-term effect of sustained virological response on hepatocellular carcinoma in patients with hepatitis C in Canada.

Background & Aims: Evidence is limited on hepatocellular carcinoma (HCC) risk after sustained virological response (SVR) to interferon-based treatment of hepatitis C virus (HCV) infection. We evaluated the effect of SVR on the risk of HCC and estimated its incidence in post-SVR HCV patients from a large population-based Canadian cohort.

Methods: The British Columbia Hepatitis Testers Cohort includes individuals tested for HCV between 1990-2013 linked with data on their medical visits, hospitalizations, cancers, prescription drugs and mortality.

The Population Level Cascade of Care for Hepatitis C in British Columbia, Canada: The BC Hepatitis Testers Cohort (BC-HTC).

Background: Population-level monitoring of hepatitis C virus (HCV) infected people across the cascade of care identifies gaps in access and engagement in care and treatment. We characterized a population-level cascade of care for HCV in British Columbia (BC), Canada and identified factors associated with leakage at each stage.

Methods: The BC Hepatitis Testers Cohort (BC-HTC) includes 1.

Twin epidemics of new and prevalent hepatitis C infections in Canada: BC Hepatitis Testers Cohort.

Background: We characterized the twin epidemics of new and prevalent hepatitis C virus (HCV) infections in British Columbia, Canada to inform prevention, care and treatment programs.

Methods: The BC Hepatitis Testers Cohort (BC-HTC) includes individuals tested for HCV, HIV or reported as a case of HBV, HCV, HIV or active TB between 1990-2013 linked with data on their medical visits, hospitalizations, cancers, prescription drugs and mortality. Prevalent infection was defined as being anti-HCV positive at first test.

Assessing Hepatitis C Burden and Treatment Effectiveness through the British Columbia Hepatitis Testers Cohort (BC-HTC): Design and Characteristics of Linked and Unlinked Participants.

Background: The British Columbia (BC) Hepatitis Testers Cohort (BC-HTC) was established to assess and monitor hepatitis C (HCV) epidemiology, cost of illness and treatment effectiveness in BC, Canada. In this paper, we describe the cohort construction, data linkage process, linkage yields, and comparison of the characteristics of linked and unlinked individuals.

Methods: The BC-HTC includes all individuals tested for HCV and/or HIV or reported as a case of HCV, hepatitis B (HBV), HIV or active tuberculosis (TB) in BC linked with the provincial health insurance client roster, medical visits, hospitalizations, drug prescriptions, the cancer registry and mortality data using unique personal health numbers.

Genetic determinants of cocaine-associated agranulocytosis.

Background: Drug-induced agranulocytosis is a recognized adverse drug event associated with serious infectious complications. Levamisole is an antihelminthic and immunomodulator withdrawn from North American markets in 2005 after reports of agranulocytosis. Previous studies of levamisole, suggest that the human leukocyte antigen (HLA)-B27 confers a genetic predisposition to this adverse drug event.

Decreasing Hepatitis C Incidence Among a Population With Repeated Tests: British Columbia, Canada, 1993-2011.

Objectives: We estimated HCV incidence among individuals who repeatedly underwent anti-HCV testing.

Methods: We studied HCV-negative individuals who had at least 2 tests between April 1992 and September 2012 in British Columbia, Canada. We calculated incidence as the number of new infections per 100 person-years at risk.

Test uptake and case detection of syphilis, HIV, and hepatitis C among women undergoing prenatal screening in British Columbia, 2007 to 2011.

Objective: Test uptake and case detection trends for rubella, syphilis, HIV, and hepatitis C (HCV) were compared among the 2007 to 2011 cohort of women undergoing prenatal testing in British Columbia. Analysis involved linkage of provincially centralized laboratory and surveillance data to assess prenatal test uptake and rates of newly diagnosed versus prevalent infections.

Methods: We included prenatal specimens submitted from BC women aged 16 to 45 years in 2007 to 2011.

A drug use survey among clients of harm reduction sites across British Columbia, Canada, 2012.

Background: In British Columbia (BC), understanding of high-risk drug use trends is largely based on survey and cohort study data from two major cities, which may not be representative of persons who use drugs in other regions. Harm reduction stakeholders, representing each of the five geographic health regions in BC, identified a need for data on drug use to inform local and regional harm reduction activities across the province. The aims of this project were to (1) develop a drug use survey that could be feasibly administered at harm reduction (HR) sites across all health regions and (2) assess the data for differences in reported drug use frequencies by region.

A cross-sectional study of public attitudes towards safer drug use practices in British Columbia, Canada.

Background: Harm reduction programs are often vulnerable to political and vocal opposition despite documented evidence of their effectiveness and economic benefit. It is not well understood if opponents to harm reduction represent the general public's attitudes.

Objective: To understand the attitudes of the people of British Columbia (BC) towards various harm reduction strategies and services, and factors associated with support for harm reduction.

Controlling chaos: the perceptions of long-term crack cocaine users in vancouver, british columbia, Canada.

People who smoke crack cocaine are described as chaotic and more likely to engage in risky sex, polysubstance use and contract infectious diseases. However, little is known about how individuals perceive smoking crack as compared to other forms of cocaine use, especially injection. We explored the lived experience of people who smoke crack cocaine.

Methadone use in relation to hepatitis C virus testing in British Columbia.

Objective: We examined methadone use among a large cohort of individuals undergoing serologic testing for hepatitis C virus (HCV) infection.

Methods: In British Columbia, community pharmacy methadone dispensations are recorded in the PharmaNet database and HCV antibody (anti-HCV) test results are recorded by the Provincial Public Reference Laboratory. Provincial HCV laboratory testing records from 1992 to 2004 were linked to methadone dispensation records from 1995-2006.

Health care costs associated with hepatitis C: a longitudinal cohort study.

Background: Disease-specific estimates of medical costs are important for health policy decision making.

Objective: To identify predictors of health care costs associated with hepatitis C virus (HCV) seropositivity across disease phases.

Methods: HCV laboratory tests from the BC Centre for Disease Control were linked to administrative data pertaining to health services and drugs dispensed to estimate costs among case subjects and controls.