Sites In British Columbia Research Articles

Utilization of publicly available data to summarize spatio-temporal patterns of fish health events of Atlantic salmon (Salmo salar) reported by marine finfish industries in British Columbia (BC), Canada.

Atlantic salmon aquaculture companies in British Columbia (BC) must report fish health events to Fisheries and Oceans Canada (DFO) as part of their licensing conditions. Our study aimed to summarize these fish health events reported by Atlantic salmon sites in BC to identify spatial and spatio-temporal clusters. We conducted descriptive, retrospective global, and local cluster analyses using Moran's I and scan statistics. Between 2016 and 2022, 265 fish health events were reported. The annual incidence ranged from 5.60 (95% CI: 3.90-7.80) to 6.86 (95% CI: 4.70-9.60) health events per 100 active site-months. The most common events were yellow mouth (60.75%; 161/265) and salmonid rickettsial septicaemia (SRS) (15.47%; 41/265). The Moran's I index was positive and significant for yellow mouth, SRS, and overall fish health events at different distance bands. Most of the spatial and spatio-temporal clusters were identified in the west-central and southwestern parts of Vancouver Island. Our study hypothesizes that management practices, environmental conditions, and water quality parameters may have influenced the increased reporting of fish health events in these regions. Overall, the study highlights the potential of publicly available data for practical risk mapping in understanding the patterns of farmed Atlantic salmon diseases in BC.

Catalytic Heaters at Oil and Gas Sites May be a Significant yet Overlooked Seasonal Source of Methane Emissions.

Successful reduction of oil and gas sector methane emissions to meet near-zero intensity targets requires the identification and mitigation of all possible sources. One potentially important source is catalytic heaters, which have largely escaped attention in regulatory and mitigation efforts despite being ubiquitous at upstream production sites in cold climate regions. This study reports direct in situ measurements of the exhaust streams of 38 natural gas-fired catalytic heaters at upstream production sites in British Columbia, Canada. All heaters in the sample showed consistently poor methane conversion with mean destruction efficiencies of 61 ± 5% while releasing 235 [+31/-28] g of methane per cubic meter of fuel. Although individual units are generally small methane sources (mean of 0.28 ± 0.04 kg/h), their prevalence means they could represent 6% of the total provincial upstream methane inventory and as an aggregate methane source could be 5× more significant than abandoned wells. Notably, these heaters are seasonal sources whose emissions would be missed in measurement campaigns occurring solely in summer months. However, additional measurements from a small number of heat medium burners demonstrate that, where feasible, methane emissions can be reduced by approximately 425× by replacing catalytic heaters with centralized heat systems.

Longitudinal dissolved oxygen patterns in Atlantic salmon aquaculture sites in British Columbia, Canada

Dissolved oxygen (DO), an important water-quality parameter required to support aquatic life, is a critical factor for determining the general biological health of the aquatic ecosystem, and the concentration of DO is a critical factor in determining salmon growth and welfare. This study used longitudinal DO concentration, recorded hourly from 21 aquaculture sites, each with loggers in three separate cages, in four areas in British Columbia, Canada, between 2015 and 2017. The measurements were evaluated based on the recommended DO concentrations for protection of salmonids from hypoxia. Using a two-stage time-series analysis, we described variations in DO concentrations measured over the study period and their associations with environmental factors. Based on the water quality criteria for DO concentration, 42.3, 56.5, and 1.2% of the hourly DO data from the overall 21 aquaculture sites were classified as ‘optimal’, ‘sub-optimal’, and ‘stressed’, respectively. The frequency of hypoxic episodes differed substantially among seasons, aquaculture sites and even among cages within sites. The effects of environmental variables on DO concentration had markedly different patterns depending on the season. Significant associations with DO concentrations were observed for temperatures in the summer and winter months, and both wind direction and remotely-sensed estimated absorption from phytoplankton [aph(443)] in the winter months. The time-series regression model results showed overall (year-round) associations of temperature, wind speed, and aph(443) with DO concentrations. Describing DO measurements at these aquaculture sites provided an understanding of how much they deviated from the recommended DO concentrations, as well as provide baseline information for future water resource planning, including continued and improved water quality monitoring in aquaculture areas.

Efficient genomics-based ‘end-to-end’ selective tree breeding framework

Since their initiation in the 1950s, worldwide selective tree breeding programs followed the recurrent selection scheme of repeated cycles of selection, breeding (mating), and testing phases and essentially remained unchanged to accelerate this process or address environmental contingencies and concerns. Here, we introduce an “end-to-end” selective tree breeding framework that: (1) leverages strategically preselected GWAS-based sequence data capturing trait architecture information, (2) generates unprecedented resolution of genealogical relationships among tested individuals, and (3) leads to the elimination of the breeding phase through the utilization of readily available wind-pollinated (OP) families. Individuals’ breeding values generated from multi-trait multi-site analysis were also used in an optimum contribution selection protocol to effectively manage genetic gain/co-ancestry trade-offs and traits’ correlated response to selection. The proof-of-concept study involved a 40-year-old spruce OP testing population growing on three sites in British Columbia, Canada, clearly demonstrating our method’s superiority in capturing most of the available genetic gains in a substantially reduced timeline relative to the traditional approach. The proposed framework is expected to increase the efficiency of existing selective breeding programs, accelerate the start of new programs for ecologically and environmentally important tree species, and address climate-change caused biotic and abiotic stress concerns more effectively.

Effect of resource supplementation on female Western Rattlesnake postpartum movement

Resource availability plays an important factor in an animal's life history by affecting growth and reproduction and influencing behaviours such as movement and thermoregulation. Female rattlesnakes in northern climes face shortened active seasons limiting the time available to replenish lost reserves from reproduction. Consequently, this leads to slower growth rates, small litters, and infrequent reproduction in these populations. With these challenges, it has been assumed postpartum rattlesnakes in these regions should return to their hibernacula immediately following parturition. However, our previous study revealed different tactics of postpartum movements by females across several study sites. To examine the relationship between resource availability and these movements, we experimentally supplemented resources (mice or mice injected with water) to free-ranging pregnant Western Rattlesnakes ( Crotalus oreganus Holbrook, 1840) at three sites in British Columbia, Canada, during 2019. We examined body condition and movement of snakes, finding that pregnant rattlesnakes consumed supplemented resources until late parturition and had significantly higher postpartum body condition than controls. Contrary to our expectations, increased access to resources ad libitum did not significantly halt or alter postpartum movements away from hibernacula. These results suggest that resource availability influences certain life-history traits such as body condition but not others like postpartum movement.

“I thought it was for guys that did needles”: Medication perceptions and lay expertise among medical research participants

IntroductionAlthough randomized controlled trials (RCTs) examine “objective” indicators of safety and efficacy of investigational drugs, participants may not perceive study medications as neutral entities. Some medications are imbued with social and cultural meaning, such as stigmatized medications for opioid use disorders. Such perceptions surrounding substance use treatments can extend to the research context and shape RCT participants' experiences with and adherence to study medications. MethodsConsidering these complexities in substance use research, we conducted a nested qualitative study within a multi-site, pragmatic RCT in Canada testing two treatments (methadone versus buprenorphine/naloxone) for opioid use disorder. Between 2017 and 2020, we conducted 115 interviews with 75 RCT participants across five trial sites in British Columbia, Alberta, Ontario, and Quebec. ResultsUsing an abductive coding approach, we characterized participants by their previous experience with medication for opioid use disorder and by their exposure to drug culture and drug scenes. Across these experience types, we identified systematic differences around participants' perceptions of the study medications, sources of information and expertise, and medication stigma. ConclusionOur findings illustrate the critical importance of social context in shaping medication beliefs and study experiences among people who use drugs, with implications for the conduct of future RCTs in substance use.

Access to tablet injectable opioid agonist therapy in rural and smaller urban settings in British Columbia, Canada: a qualitative study

BackgroundRural and smaller urban settings in Canada are disproportionately impacted by the overdose crisis, highlighting the need for novel public health interventions within these jurisdictions. Tablet injectable opioid agonist therapy (TiOAT) programs have been implemented in select rural communities as a means to address drug-related harms. However, little is known about the accessibility of these novel programs. Therefore, we conducted this study to understand the rural context and factors that affected access of TiOAT programs.MethodsBetween October 2021 to April 2022, individual qualitative semi-structured interviews were conducted with 32 individuals enrolled in a TiOAT program at participating rural and smaller urban sites in British Columbia, Canada. Interview transcripts were coded using NVivo 12 and data were analyzed thematically.ResultsTiOAT access varied considerably. TiOAT delivery in rural settings is complicated due to geographic challenges. Participants who were homeless and staying at a nearby shelter or those in centrally-located supportive housing had minimal issues compared to those living in more affordable housing on the outskirts of town with limited transportation options. Dispensing policies that required daily-witnessed ingestion multiple times daily were challenging for most. Only one site provided evening take-home doses whereas participants at the other site could only resort to the illicit opioid supply to address withdrawal outside of program hours. Participants described the clinics as providing a positive and familial social environment compared to experiences of stigma elsewhere. Medication interruptions did occur when participants were in hospital and custodial settings, leading to withdrawal, program discontinuation, and overdose risk.ConclusionsThis study highlights the beneficial ways in which health services tailored for people who use drugs can create a stigma-free environment with an emphasis on social bonds. Other factors such as transportation access, dispensing policies, and access in rural hospitals and custodial settings produced unique challenges for rural people who use drugs. Public health authorities in rural and smaller settings should consider these factors when designing, implementing, and scaling up future substance use services, including TiOAT programs.

Clinical Supervision, Workplace Culture, and Therapeutic Engagements with Youth at Risk for Suicide

Clinical supervision practices and workplace cultures are highly influential in shaping the quality of care that clients at risk for suicide receive. The purpose of this qualitative study was to document counselors’ and supervisors’ views regarding the supervisory practices and conditions that enable useful and life-enhancing practices when working with youth who struggle with living. We conducted two, 1.5-hour focus groups with counselors who work with youth at risk for suicide in two separate clinical sites in British Columbia, representing the views of seven counselors. Two clinical supervisors who each supervise a small team of counselors were interviewed individually. Reflexive thematic analysis, informed by a constructionist lens was used to organize and interpret the qualitative data, with a strong emphasis on researcher subjectivity, reflexivity, and the contextual nature of meaning-making. Four themes were generated: being guided by a flexible framework; addressing anxiety in a systemic way; resourcing self and others; and expanding possibilities for engaging with complexity. We argue in favor of flexible, relational, and reflexive approaches to supervision, where the development of useful responses to suicidal behavior can best be understood as a shared, system-wide responsibility, which does not place the onus for “saving lives” onto the shoulders of individual counselors.

Baseline Inappropriate Antibiotic Use in Primary Care Patients with Viral Respiratory Tract Infections with 2019 and 2020.

Context: Respiratory tract infection (RTI) is the leading cause of avoidable antimicrobial use in primary care. How the COVID-19 pandemic has impacted antibiotic prescribing practices across Canada is unknown. The purpose of this study was to examine rates of antibiotic prescribing for RTI in primary care during the first year of the pandemic (2020), compared to baseline in 2019. Study Design and Analysis: Cross sectional study. Dataset: Canadian Primary Care Sentinel Surveillance Network electronic medical record data from sites in British Columbia, Alberta, Manitoba, Ontario, Quebec, Nova Scotia and Newfoundland. Population Studied: Patients that met the case definition criteria for an RTI or a Urinary Tract Infection (UTI) in 2019, and in 2020. Outcome measures: We examined oral antibiotic prescribing for patients who were identified as having a primary care visit for RTI. The same analysis was repeated for urinary tract infection (UTI) as a tracer condition. The antibiotic use considered avoidable for RTI was defined by Choosing Wisely Canada. Results: A total of 1,692,876 patients with a valid birth year and sex and at least one visit to primary care in 2019 and 2020 were included. Patient visits for RTI decreased from 2.3% in 2019 to 1.6% in 2020 (p<.0001), as did patient visits for UTI (1.1% vs 0.7%, p<.0001). In 2019, 28.0% of patients visits for RTI were prescribed an antibiotic, and this proportion decreased significantly to 20.6% in 2020 (<.0001). The drop in antibiotic prescriptions for RTI was driven by a decrease in prescribing for common cold (13.6% vs. 11.3%, <.0001) and for acute bronchitis/asthma (15.2% vs. 7.3%, p<.0001). In comparison, antibiotic prescribing for visits related to UTI increased marginally between 2019 and 2020 (71.6% vs. 72.3%, p=0.007). Conclusions: A significant decrease in antibiotic prescribing for RTI across primary care was observed during the first year of the COVID-19 pandemic, likely related to the changes in epidemiology and care delivery models in primary care. CPCSSN can provide pan-Canadian surveillance of antibiotic prescribing practices in primary care that can be used for provider feedback and quality improvement.

Tree regeneration on stumps in second-growth temperate rainforests of British Columbia, Canada

The significance of stumps and other coarse woody debris in maintaining biodiversity has been widely recognized in temperate rainforests, however, there is a paucity of research on the role of stumps in tree regeneration. We studied vascular plant diversity, island species area-relationship, and tree regeneration on stumps in temperate rainforests across three sites in British Columbia, Canada (Malcom Knapp Research Forest, MKRF; Pacific Spirit Regional Park, PSRP; and Stanley Park, SP). Our results were: 1) identification of 19 vascular plant species on stumps, including eight tree species, 2) the number of plants established on stumps observed convex up shape in MKRF and sigmoid shape for PSRP and SP, 3) the overall species established on stumps were positively associated in MKRF (Variance ratio = 2.74) and SP (Variance ratio = 1.37), but negatively associated in PSRP (Variance ratio = 0.57), and 4) tree species appeared to compete with each other on stumps and likely to co-occur with understorey species. Our results highlight species relationships and stumps diameter are major factors affecting tree regeneration on stumps in these second-growth temperate rainforests. We synthesized our results in a schematic of tree regeneration processes on stumps, which could be used to stimulate ideas for new hypothesis generation and for studies relevant to conservation and management. • After forest disturbance, stumps plays an important role in providing micro-ecological regeneration habitat. • Tree regeneration on stumps represents a unique temporal ecological process. • The process of vascular plant species establishment and competition during tree regeneration have not been fully explored. • Understanding tree regeneration process of on stumps could provide scientific basis for ecological conservation and management in temperature rainforests.

Motivations for concurrent use of uppers and downers among people who access harm reduction services in British Columbia, Canada: findings from the 2019 Harm Reduction Client Survey

IntroductionAn increase in crystal methamphetamine (methamphetamine) use during the overdose epidemic is being observed in British Columbia (BC), Canada, and across North America. Concurrent use (ie, using uppers and downers...

Evaluating the population-level effects of overdose prevention sites and supervised consumption sites in British Columbia, Canada: Controlled interrupted time series.

BackgroundOn 14 April 2016, British Columbia’s Provincial Medical Health Officer declared the overdose crisis a public health emergency, sanctioning the implementation of new overdose prevention sites (OPS) and supervised consumption sites (SCS) across the province.MethodsWe used the BC Centre for Disease Control’s Provincial Overdose Cohort of all overdose events between 1 January 2015 and 31 December 2017 to evaluate the population-level effects of OPSs and SCSs on acute health service use and mortality. We matched local health areas (LHA) that implemented any site with propensity score matched controls and conducted controlled interrupted time series analysis.ResultsDuring the study period, twenty-five OPSs and SCSs opened across fourteen of British Columbia’s 89 LHAs. Results from analysis of LHAs with matched controls (i.e. excluding Vancouver DTES) were mixed. Significant declines in reported overdose events, paramedic attendance, and emergency department visits were observed. However, there were no changes to trends in monthly hospitalization or mortality rates. Extensive sensitivity analyses found these results persisted.ConclusionsWe found OPSs and SCSs reduce opioid-related paramedic attendance and emergency department visit rates but no evidence that they reduce local hospitalization or mortality rates.

Photovoice exploration of physical activity norms and values among rural and remote pulmonary rehabilitation participants in British Columbia, Canada

Purpose Individuals with chronic obstructive pulmonary disease (COPD) engage in less physical activity compared to the general population, which can lead to worsened symptoms. In pulmonary rehabilitation (PR) programs, participants learn strategies to complete activities more easily. For such strategies to be effective, however, PR clinicians must understand their clients’ activity values and practices within their geocultural contexts. In this qualitative study, our aim was to explore physical activity norms and values among people with COPD living in remote and rural locations, using Photovoice methodology. Materials and methods We recruited 12 participants from rural PR sites in British Columbia, Canada. During two distinct seasons (winter and summer), participants photographed meaningful activities then completed semi-structured interviews. We analyzed transcripts using a three-step hermeneutic method, which revealed three themes. Results Participants discussed feeling conflicted regarding their COPD symptoms and physical activity, as difficulties in activity engagement cause stress, but remaining active also fosters a sense of purpose and well-being. Meanwhile, participants’ activities are inextricably linked to their rural, remote, and seasonal environment. Conclusions Our study provides insight into how people with COPD resiliently engage in activities in a rural environment with distinct weather variations. Findings highlight the importance of considering individual factors when recommending activities in PR programs. Implications for rehabilitation Although people with chronic lung disease often encounter difficulty and stress in completing their daily activities, they both recognize the importance of and derive great personal meaning from remaining active. The unique social, geographical, physical, and climatic environments of rural and remote dwelling people with chronic lung disease can both enable and challenge their activity engagement. Pulmonary rehabilitation (PR) programs and clinicians must situate their activity recommendations within the geographic contexts of their clients – which can vary across the seasons. Support for participants’ mental health is a vital aspect of PR.

Increased prevalence and severity of Kudoa thyrsites (Cnidaria: Myxosporea) in Atlantic salmon Salmo salar exposed to deeper seawater

Kudoa thyrsites is a myxozoan parasite of marine fish with a global distribution. In British Columbia (BC), Canada, severe infections are associated with an economically significant degradation of fillet quality in farmed Atlantic salmon. Exposures to naturally occurring actinospores at a coastal research laboratory were used to test the hypothesis that the prevalence and severity of K. thyrsites infections acquired by exposure of Atlantic salmon to seawater (SW) of various depths are not different. In Expt 1, fish were exposed to SW from 1, 7 or 13 m below the surface. Following exposure to deeper-sourced SW, the prevalence of K. thyrsites, determined from microscopic examination of muscle histology sections, was greater in all 4 trials and the severity of infection was greater in 2 trials. In Expt 2, infections were compared over time among salmon held in tanks supplied with deep-sourced SW (raw or UV-irradiated) or in a surface net-pen. The infection was observed in 35 of 40 fish sampled between 3 and 6 mo after tank exposure to raw SW. Coincidentally, the parasite was observed in 4 of 40 fish maintained in the net-pen. No consistent association of the parasite infection was observed with temperature; however, reduced salinity and solar radiation were not ruled out as factors which may reduce the risk of infection from surface SW. These findings require verification at commercial aquaculture sites in BC, as they will inform considerations related to farm siting and net-pen configuration.

Minerals for War: British Columbia’s Production of Mercury and Tungsten in World War Two

Abstract: Allied manufacturing of munitions during the Second World War caused labour shortages and decreased production in British Columbia’s mining sector. The provincial Department of Mines supported efforts by the federal Department of Munitions and Supply to ensure war industries had sufficient supplies of strategically important metals. Close cooperation between Canada and the United States encouraged American investment in new metal sources in Canada. A pressing need for tungsten and mercury led to opening British Columbia mines with their production supplanting overseas sources for important minerals in support of Allied economic warfare strategies. The war focused attention on two unique sites in British Columbia which illustrate the unusual demands and fears of wartime.

Pathogenicity of seedborne Alternaria and Stemphylium species and stem-infecting Neofusicoccum and Lasiodiplodia species to cannabis (Cannabis sativa L., marijuana) plants

Cannabis (Cannabis sativa L., marijuana) plants grown at indoor and outdoor production sites in British Columbia (BC) and Ontario with stem canker symptoms were sampled and affected tissues were surface-sterilized and plated onto potato dextrose agar. Isolates were identified by colony and spore morphology as well as PCR amplification and sequencing of the ITS1-ITS2 rDNA, beta-tubulin, and actin gene regions. The most frequently isolated fungi were Alternaria alternata, Neofusicoccum parvum, and Lasiodiplodia theobromae. In addition, A. alternata was recovered from cannabis inflorescences in BC as well as surface-sterilized hemp seed. Stemphylium vesicarium was isolated from hemp seeds for the first time. The pathogenicity of all these fungi to cannabis plants was confirmed by inoculation of leaves, stems, buds, rooted cuttings and mature plants. Disease ratings varied depending on both tissue type and pathogen. Both L. theobromae and N. parvum produced extensive stem cankers on mature cannabis plants as well as extensive lesions on leaves. All pathogens showed optimal colony growth in culture at 25-30ºC. A comparison of the susceptibility of five cannabis genotypes to foliar infection by N. parvum indicated there were significant differences (p < 0.05) in lesion size, with some genotypes showing high susceptibility and others showing resistance. This is the first report of L. theobromae, N. parvum, A. alternata, and S. vesicarium causing stem canker and leaf spot symptoms on cannabis in Canada. The recovery of these fungi adds to the growing list of pathogens that cause infection and loss of quality in cannabis production.

Efficacy of delayed entry low branch sanitation pruning in preventing mortality of western white pine infected with white pine blister rust

White pine blister rust, caused by the fungus Cronartium ribicola J. C. Fisch., is a virulent mortality agent of five-needle pines like western white pine (Pinus monticola D. Don.). For decades, low branch pruning has been recommended as a control by removing cankers that can migrate from infected branches to the tree stem and kill the host. These recommendations are mainly based on studies done on eastern white pine (Pinus strobus L.), or on western white pine growing primarily in the Interior Pacific Northwest of the United States. It is not clear whether these recommendations are transferable to geographically and climatically dissimilar Pacific coastal areas, where pruning often shows little benefit in commercial forest plantations. We summarize over 30 years of post-treatment data from coastal and interior sites in British Columbia. Sanitation pruning was done on 12–22-year-old stands using one or two pruning lifts and infection and mortality were tracked over the subsequent decades. Our results show that while pruning had little negative effect on treated tree height or diameter growth, mortality was not significantly different between treated and untreated groups across all sites. Cumulative mortality after three decades was >80% for coastal sites, and nearly 60% for the interior site, indicating a lack of treatment efficacy. Our results differ from earlier shorter duration studies and those from other jurisdictions. It is clear that delaying pruning until trees are older and carrying many existing branch and stem infections results in ineffective control of rust in coastal white pine stands.

Acceptability of technological solutions for overdose monitoring: Perspectives of people who use drugs

Introduction Rising overdose deaths are a devastating problem across the United States and Canada. Despite the availability of observed consumption sites in British Columbia (BC), data suggest people who use drugs (PWUD) alone in private residences are most at risk of overdose death. These individuals may not use consumption sites due to fear of stigmatization, lack of privacy, or personal preference. It is this population that would benefit from overdose monitoring alternatives. Methods This 2018 study employed two sources of data. (1) A provincial harm reduction distribution site client survey administered at 27 sites across BC asked about cell phone possession and functionality. (2) Structured interviews with PWUD in Vancouver gathered perspectives regarding monitoring devices and alerting systems. Results: The client survey was administered to 486 individuals. Among 443 respondents, 48% (n = 212) owned a cellphone and 68% (n = 115) of individuals with a cellphone with access to internet (n = 168) would use an application to mitigate opioid-related overdose deaths. Thirty qualitative interviews were performed; thematic analysis of the responses identified three major themes – safety, public versus private drug use, and technological monitoring and function. The relevance of technological devices was affected by the inconsistent availability of cellphones, concerns about anonymity, as well as personal comfort while using drugs. Conclusions: Technological applications may not be suitable for clients with transient lifestyles, no permanent home, and lack of consistent access to a mobile device. Thorough needs assessments, considerations of lifestyle limitations, and understanding perceptions around cellphone and overdose monitoring can increase the potential that devices will be used. Highlights 45% (n = 219) of client survey respondents owned a cellphone Out of cellphone owners, 59% (n = 102) of client survey respondents had access to internet Of 168 with internet access, 68% willing to use any applications for overdose response Applications not suitable for transient lifestyles, no permanent home, and lack of consistent access to cellphone

Power of Connections: How a Novel Canadian Men’s Wellness Program is Improving the Health and Well-Being of Indigenous and Non-Indigenous Men

The DUDES Club is a novel men’s health and wellness organization founded in 2010 in Vancouver, BC. Since 2017, the DUDES Club has rapidly expanded in Northern BC and, with the help of a partnership with the First Nations Health Authority, has grown to include 40 sites in British Columbia and 2 sites nationally. In this study, we analyze interviews (n = 5) and 15 focus groups (n = 101) conducted as part of a program evaluation with DUDES Club members, Elders, providers, and health care professionals. We focus on men’s experiences with the DUDES Club to identify four main themes in the data: brotherhood and community, accessible health care information, disrupting colonial constructions of masculinity, and systemic and structural challenges. We conclude with policy recommendations.

Crystal methamphetamine use in British Columbia, Canada: A cross-sectional study of people who access harm reduction services.

IntroductionIncreased use of crystal methamphetamine (“crystal meth”) has been observed across North America and international jurisdictions, including a notable increase in the presence of methamphetamines in illicit drug toxicity deaths in British Columbia (BC), Canada. We used data from a cross-sectional survey and urine toxicology screening to report the prevalence, correlates, and validity of self-reported crystal meth use among clients of harm reduction sites in BC.Materials and methodsSurvey data were collected from 1,107 participants across 25 communities in BC, through the 2018 and 2019 Harm Reduction Client Survey. We described reported substance use and used a multivariate logistic regression model to characterize crystal meth use. Urine samples provided by a subset of participants were used to derive validity of self-reported three-day crystal meth use compared to urine toxicology screening.ResultsExcluding tobacco, crystal meth was the most frequently reported substance used in the past three days in 2018 and 2019 (59.7% and 71.7%, respectively). Smoking was the dominant route of administration for crystal meth, crack, heroin, and fentanyl. Multivariate analysis determined significantly higher odds of crystal meth use among those who used opioids (Adjusted Odds Ratio [AOR] = 3.13), cannabis (AOR = 2.10), and alcohol (1.41), and among those who were not regularly housed (AOR = 2.08) and unemployed (AOR = 1.75). Age ≥50 was inversely associated with crystal meth use (AOR = 0.63). Sensitivity of self-reported crystal meth use was 86%, specificity was 86%, positive predictive value was 96%, and negative predictive value was 65%.ConclusionsCrystal meth was the most commonly used substance among clients of harm reduction sites in BC in 2018 and 2019, and was frequently used concurrently with opioids. Comparison to urine samples demonstrated high validity of self-reported crystal meth use. Understanding evolving patterns of substance use will be imperative in tailoring harm reduction and substance use services for individuals that use crystal meth.