Smoking identified as preferred mode of opioid safe supply use; investigating correlates of smoking preference through a 2021 cross-sectional study in British Columbia.

BACKGROUND: The increasing number of illicit drug toxicity deaths in British Columbia (BC) has led to calls for a regulated (pharmaceutical grade) supply of substances ("safe supply"). In order to inform safe supply recommendations, we aimed to identify why people currently smoke opioids and assess the preferred mode of consumption if people who use opioids were provided with opioid safe supply. METHODS: The BC Harm Reduction Client Survey (HRCS) is an annual survey that gathers information about people who use drugs' (PWUD) substance use characteristic with the goal of contributing to evidence-based policy. This study utilized data from the 2021 HRCS. The outcome variable was "prefer smoking opioid safe supply" ('yes/no'). Explanatory variables included participants' demographics, drug use, and overdose characteristics. Bivariate and hierarchical multivariable logistic regressions were conducted to identify factors associated with the outcome. RESULTS: Of 282 total participants who indicated a preference for a mode of consumption for opioid safe supply, 62.4% preferred a smokable option and 19.9% preferred to inject if provided with opioid safe supply. Variables significantly associated with the outcome (preferred smoking) included: being 19-29 years old (AOR=5.95, CI =1.93 - 18.31) compared to >50 years old, having witnessed an overdose in the last 6 months (AOR=2.26, CI=1.20 - 4.28), having smoked opioids in the last 3 days (AOR=6.35, CI=2.98 - 13.53) and having a preference to smoke stimulants safe supply (AOR=5.04, CI=2.53 - 10.07). CONCLUSION: We found that over half of participants prefer smokable options when accessing opioid safe supply. Currently in BC, there are limited smokable opioid safe supply options as alternatives to the toxic street supply. To reduce overdose deaths, safe supply options should be expanded to accommodate PWUD that prefer smoking opioids.

Disparities in self-reported healthcare access for airways disease in British Columbia, Canada, during the COVID-19 pandemic. Insights from a survey co-developed with people living with asthma and chronic obstructive pulmonary disease.

Patients' perspectives on the impact of the COVID-19 pandemic on their access to asthma and COPD healthcare could inform better, more equitable care delivery. We demonstrate this topic using British Columbia (BC), Canada, where the impact of the pandemic has not been described. We co-designed a cross-sectional survey with patient partners and administered it to a convenience sample of people living with asthma and COPD in BC between September 2020 and March 2021. We aimed to understand how access to healthcare for these conditions was affected during the pandemic. The survey asked respondents to report their characteristics, access to healthcare for asthma and COPD, types of services they found disrupted and telehealth (telephone or video appointment) use during the pandemic. We analysed 433 responses and found that access to healthcare for asthma and COPD was lower during the pandemic than pre-pandemic (p < 0.001). Specialty care services were most frequently reported as disrupted, while primary care, home care and diagnostics were least disrupted. Multivariable logistic regression revealed that access during the pandemic was positively associated with self-assessed financial ability (OR = 22.0, 95% CI: 7.0 - 84.0, p < 0.001, reference is disagreeing with having financial ability) and living in medium-sized urban areas (OR = 2.3, 95% CI: 1.0 - 5.2, p = 0.04, reference is rural areas). These disparities in access should be validated post-pandemic to confirm whether they still persist. They also indicate the continued relevance of exploring approaches for more equitable healthcare.

Association of COVID-19 Infection With Incident Diabetes.

Importance: SARS-CoV-2 infection may lead to acute and chronic sequelae. Emerging evidence suggests a higher risk of diabetes after infection, but population-based evidence is still sparse. Objective: To evaluate the association between COVID-19 infection, including severity of infection, and risk of diabetes. Design, Setting, and Participants: This population-based cohort study was conducted in British Columbia, Canada, from January 1, 2020, to December 31, 2021, using the British Columbia COVID-19 Cohort, a surveillance platform that integrates COVID-19 data with population-based registries and administrative data sets. Individuals tested for SARS-CoV-2 by real-time reverse transcription-polymerase chain reaction (RT-PCR) were included. Those who tested positive for SARS-CoV-2 (ie, those who were exposed) were matched on sex, age, and collection date of RT-PCR test at a 1:4 ratio to those who tested negative (ie, those who were unexposed). Analysis was conducted January 14, 2022, to January 19, 2023. Exposure: SARS-CoV-2 infection. Main Outcomes and Measures: The primary outcome was incident diabetes (insulin dependent or not insulin dependent) identified more than 30 days after the specimen collection date for the SARS-CoV-2 test with a validated algorithm based on medical visits, hospitalization records, chronic disease registry, and prescription drugs for diabetes management. Multivariable Cox proportional hazard modeling was performed to evaluate the association between SARS-CoV-2 infection and diabetes risk. Stratified analyses were performed to assess the interaction of SARS-CoV-2 infection with diabetes risk by sex, age, and vaccination status. Results: Among 629 935 individuals (median [IQR] age, 32 [25.0-42.0] years; 322 565 females [51.2%]) tested for SARS-CoV-2 in the analytic sample, 125 987 individuals were exposed and 503 948 individuals were unexposed. During the median (IQR) follow-up of 257 (102-356) days, events of incident diabetes were observed among 608 individuals who were exposed (0.5%) and 1864 individuals who were not exposed (0.4%). The incident diabetes rate per 100 000 person-years was significantly higher in the exposed vs nonexposed group (672.2 incidents; 95% CI, 618.7-725.6 incidents vs 508.7 incidents; 95% CI, 485.6-531.8 incidents; P < .001). The risk of incident diabetes was also higher in the exposed group (hazard ratio [HR], 1.17; 95% CI, 1.06-1.28) and among males (adjusted HR, 1.22; 95% CI, 1.06-1.40). The risk of diabetes was higher among people with severe disease vs those without COVID-19, including individuals admitted to the intensive care unit (HR, 3.29; 95% CI, 1.98-5.48) or hospital (HR, 2.42; 95% CI, 1.87-3.15). The fraction of incident diabetes cases attributable to SARS-CoV-2 infection was 3.41% (95% CI, 1.20%-5.61%) overall and 4.75% (95% CI, 1.30%-8.20%) among males. Conclusions and Relevance: In this cohort study, SARS-CoV-2 infection was associated with a higher risk of diabetes and may have contributed to a 3% to 5% excess burden of diabetes at a population level.

Risk mitigation guidance and safer supply prescribing among young people who use drugs in the context of COVID-19 and overdose emergencies.

Across North America, overlapping overdose and COVID-19 emergencies have had a substantial impact on young people who use drugs (YPWUD). New risk mitigation guidance (RMG) prescribing practices were introduced in British Columbia, Canada, in 2020 to allow people to decrease risk of overdose and withdrawal and better self-isolate. We examined how the prescribing of hydromorphone tablets specifically impacted YPWUD's substance use and care trajectories. Between April 2020 and July 2021, we conducted virtual interviews with 30 YPWUD who had accessed an RMG prescription of hydromorphone in the previous six months and 10 addiction medicine physicians working in Vancouver. A thematic analysis was conducted. YPWUD participants highlighted a disjuncture between RMG prescriptions and the safe supply of unadulterated substances such as fentanyl, underscoring that having access to the latter is critical to reducing their reliance on street-based drug markets and overdose-related risks. They described re-appropriating these prescriptions to meet their needs, stockpiling hydromorphone so that it could be used as an "emergency backup" when they were unable to procure unregulated, illicit opioids. In the context of entrenched poverty, hydromorphone was also used to generate income for the purchase of drugs and various necessities. For some YPWUD, hydromorphone prescriptions could be used alongside opioid agonist therapy (OAT) to reduce withdrawal and cravings and improve adherence to OAT. However, some physicians were wary of prescribing hydromorphone due to the lack of evidence for this new approach. Our findings underscore the importance of providing YPWUD with a safe supply of the substances they are actively using alongside a continuum of substance use treatment and care, and the need for both medical and community-based safe and safer supply models.

Urban-rural divide in COVID-19 infection and vaccination rates in healthcare workers in British Columbia, Canada.

Introduction: Healthcare workers (HCWs) play a critical role in responding to the COVID-19 pandemic. Early in the pandemic, urban centres were hit hardest globally; rural areas gradually became more impacted. We compared COVID-19 infection and vaccine uptake in HCWs living in urban versus rural locations within, and between, two health regions in British Columbia (BC), Canada. We also analysed the impact of a vaccine mandate for HCWs. Methods: We tracked laboratory-confirmed SARS-CoV-2 infections, positivity rates and vaccine uptake in all 29,021 HCWs in Interior Health (IH) and all 24,634 HCWs in Vancouver Coastal Health (VCH), by occupation, age and home location, comparing to the general population in that region. We then evaluated the impact of infection rates as well as the mandate on vaccination uptake. Results: While we found an association between vaccine uptake by HCWs and HCW COVID-19 rates in the preceding 2-week period, the higher rates of COVID-19 infection in some occupational groups did not lead to increased vaccination in these groups. By 27 October 2021, the date that unvaccinated HCWs were prohibited from providing healthcare, only 1.6% in VCH compared with 6.5% in IH remained unvaccinated. Rural workers in both areas had significantly higher unvaccinated rates compared with urban dwellers. Over 1800 workers, comprising 6.7% of rural HCWs and 3.6% of urban HCWs, remained unvaccinated and set to be terminated from their employment. While the mandate prompted a significant increase in uptake of second doses, the impact on the unvaccinated was less clear. Conclusions: As rural areas often suffer from under-staffing, loss of HCWs could have serious impacts on healthcare provision as well as on the livelihoods of unvaccinated HCWs. Greater efforts are needed to understand how to better address the drivers of rural-related vaccine hesitancy.

Résumé Introduction: Les travailleurs de la santé (TS) jouent un rôle essentiel dans la réponse à la pandémie de COVID-19. Au début de la pandémie, les centres urbains ont été les plus durement touchés à l'échelle mondiale; les zones rurales ont progressivement été plus touchées. Nous avons comparé l'infection à la COVID-19 et l'adoption du vaccin chez les travailleuses et travailleurs de la santé vivant dans des zones urbaines et rurales au sein de deux régions sanitaires de la Colombie-Britannique (C.-B.), au Canada, et entre ces régions. Nous avons également analysé l'impact d'un mandat de vaccination pour les travailleuses et travailleurs de la santé. Méthodes: Nous avons suivi les infections au SRAS-CoV-2 confirmées en laboratoire, les taux de positivité et l'adoption du vaccin chez les 29 021 TS d'Interior Health (IH) et les 24 634 TS de Vancouver Coastal Health (VCH), par profession, âge et lieu de résidence, en les comparant à la population générale de cette région. Nous avons ensuite évalué l'impact des taux d'infection ainsi que du mandat sur le recours à la vaccination. Résultats: Bien que nous ayons trouvé une association entre l'adoption du vaccin par les TS et les taux de COVID-19 des travailleurs de la santé au cours de la période de deux semaines précédentes, les taux plus élevés d'infection par la COVID-19 dans certains groupes professionnels n'ont pas entraîné une augmentation de la vaccination dans ces groupes. En date du 27 octobre 2021, date à laquelle il était interdit aux travailleuses et travailleurs de santé non vaccinés de fournir des soins de santé, seul 1,6% des travailleuses et travailleurs de la VCH, contre 6,5% des travailleuses et travailleurs de l'IH, n'étaient toujours pas vaccinés. Les travailleuses et travailleurs ruraux des deux zones présentaient des taux de non-vaccination significativement plus élevés que les citadins. Plus de 1 800 travailleuses et travailleurs, soit 6,7% des TS ruraux et 3,6% des TS urbains, n'étaient toujours pas vaccinés et devaient être licenciés. Bien que le mandat ait entraîné une augmentation significative de la prise des deuxièmes doses, l'impact sur les personnes non-vaccinées était moins clair. Conclusions: Comme les zones rurales souffrent souvent d'un manque de personnel, la perte de TS pourrait avoir de graves répercussions sur la prestation des soins de santé ainsi que sur les moyens de subsistance des TS non-vaccinés. Des efforts plus importants sont nécessaires pour comprendre comment mieux aborder les facteurs d'hésitation à SE faire vacciner en milieu rural. Mots-clés: Travailleuses et travailleurs de la santé, COVID-19, vaccination, mandat de vaccination, milieu rural.

SARS-CoV-2 testing and COVID-19-related primary care use among people with citizenship, permanent residency, and temporary immigration status: an analysis of population-based administrative data in British Columbia.

OBJECTIVES: Having temporary immigration status affords limited rights, workplace protections, and access to services. There is not yet research data on impacts of the COVID-19 pandemic for people with temporary immigration status in Canada. METHODS: We use linked administrative data to describe SARS-CoV-2 testing, positive tests, and COVID-19 primary care service use in British Columbia from January 1, 2020 to July 31, 2021, stratified by immigration status (citizen, permanent resident, temporary resident). We plot the rates of people tested and confirmed positive for COVID-19 by week from April 19, 2020 to July 31, 2021 across immigration groups. We use logistic regression to estimate adjusted odds ratios of a positive SARS-CoV-2 test, access to testing, and primary care among people with temporary status or permanent residency, compared with people who hold citizenship. RESULTS: A total of 4,146,593 people with citizenship, 914,089 people with permanent residency, and 212,215 people with temporary status were included. Among people with temporary status, 52.1% had "male" administrative sex and 74.4% were ages 20-39, compared with 50.1% and 24.4% respectively among those with citizenship. Of people with temporary status, 4.9% tested positive for SARS-CoV-2 over this period, compared with 4.0% among people with permanent residency and 2.1% among people with citizenship. Adjusted odds of a positive SARS-CoV-2 test among people with temporary status were almost 50% higher (aOR 1.42, 95% CI 1.39, 1.45), despite having half the odds of access to testing (aOR 0.53, 95% CI 0.53, 0.54) and primary care (aOR 0.50, 95% CI 0.49, 0.52). CONCLUSION: Interwoven immigration, health, and occupational policies place people with temporary status in circumstances of precarity and higher health risk. Reducing precarity accompanying temporary status, including regularization pathways, and decoupling access to health care from immigration status can address health inequities.

RéSUMé: OBJECTIFS: Le statut d'immigration temporaire confère des droits, des mesures de protection au travail et un accès aux services limités. Il n'y a pas encore de données de recherche sur les impacts de la pandémie de COVID-19 chez les personnes ayant un statut d'immigration temporaire au Canada. MéTHODE: Nous utilisons des données administratives maillées pour décrire le dépistage du SRAS-CoV-2, les tests positifs et l'utilisation des services de soins de première ligne liés à la COVID-19 en Colombie-Britannique entre le 1er janvier 2020 et le 31 juillet 2021, stratifiées selon le statut d'immigration (citoyenneté, résidence permanente, résidence temporaire). Nous reportons sur des graphiques les taux hebdomadaires de personnes testées et confirmées positives pour la COVID-19 entre le 19 avril 2020 et le 31 juillet 2021 dans les groupes d'immigration. Nous utilisons la régression logistique pour estimer les rapports de cotes ajustés d'un test positif pour le SRAS-CoV-2, de l'accès au dépistage et de l'accès aux soins primaires chez les personnes ayant le statut de résidents temporaires ou permanents comparativement aux personnes ayant la citoyenneté canadienne. RéSULTATS: En tout, 4 146 593 citoyens, 914 089 résidents permanents et 212 215 résidents temporaires ont été inclus. Chez les personnes ayant le statut de résidents temporaires, 52,1 % étaient de sexe administratif « masculin ¼ et 74,4 % avaient entre 20 et 39 ans, contre 50,1 % et 24,4 % respectivement chez les personnes ayant la citoyenneté. Chez les résidents temporaires, 4,9 % avaient obtenu un test positif pour le SRAS-CoV-2 au cours de la période de l'étude, contre 4 % chez les résidents permanents et 2,1 % chez les citoyens. La probabilité ajustée d'un test positif pour le SRAS-CoV-2 chez les personnes ayant le statut de résidents temporaires était près de 50 % plus élevée (RCa 1,42, IC de 95 % 1,39, 1,45), même si leurs probabilités d'accès au dépistage (RCa 0,53, IC de 95 % 0,53, 0,54) et aux soins primaires (RCa 0,50, IC de 95 % 0,49, 0,52) étaient moitié moindres. CONCLUSION: La conjugaison des politiques d'immigration, de santé et de main-d'œuvre met les personnes ayant le statut de résidents temporaires en situation de précarité et de risques accrus pour la santé. La réduction de la précarité qui accompagne le statut temporaire, dont les voies de régularisation, et le découplage entre l'accès aux soins de santé et le statut d'immigration pourraient répondre aux iniquités en santé.

"It's just a perfect storm": Exploring the consequences of the COVID-19 pandemic on overdose risk in British Columbia from the perspectives of people who use substances.

BACKGROUND: Despite the implementation and expansion of public health and harm reduction strategies aimed at preventing and reversing overdoses, rates of overdose-related events and fatalities continue to rise in British Columbia. The COVID-19 pandemic created a second, concurrent public health emergency that further exacerbated the illicit drug toxicity crisis, reinforced existing social inequities and vulnerabilities, and highlighted the precariousness of systems in place that are meant to protect the health of communities. By exploring the perspectives of people with recent experience of illicit substance use, this study sought to characterize how the COVID-19 pandemic and associated public health measures influenced risk and protective factors related to unintentional overdose by altering the environment in which people live and use substances, influencing the ability of people who use substances to be safe and well. METHODS: One-on-one semi-structured interviews were conducted by phone or in-person with people who use illicit substances (n = 62) across the province. Thematic analysis was performed to identify factors shaping the overdose risk environment. RESULTS: Participants pointed to factors that increased risk of overdose, including: [1] physical distancing measures that created social and physical isolation and led to more substance use alone without bystanders nearby able to respond in the event of an emergency; [2] early drug price spikes and supply chain issues that created inconsistencies in drug availability; [3] increasing toxicity and impurities in unregulated substances; [4] restriction of harm reduction services and supply distribution sites; and [5] additional burden placed on peer workers on the frontlines of the illicit drug toxicity crisis. Despite these challenges, participants highlighted factors that protected against overdose and substance-related harm, including the emergence of new programs, the resiliency of communities of people who use substances who expanded their outreach efforts, the existence of established social relationships, and the ways that individuals consistently prioritized overdose response over concerns about COVID-19 transmission to care for one another. CONCLUSIONS: The findings from this study illustrate the complex contextual factors that shape overdose risk and highlight the importance of ensuring that the needs of people who use substances are addressed in future public health emergency responses.

Perceptions of COVID-19 risk, vaccine access and confidence: a qualitative description of South Asians in Canada.

OBJECTIVES: In the first full year of the COVID-19 pandemic (2020), South Asians living in the Greater Toronto and Hamilton Area (GTHA) and Greater Vancouver area (GVA) experienced specific barriers to accessing SARS-CoV-2 testing and reliable health information. However, between June 2021 and February 2022, the proportion of people having received at least one COVID-19 vaccine dose was higher among this group (96%) than among individuals who were not visible minorities (93%). A better understanding of successful approaches and the challenges experienced by those who remain unvaccinated among this highly vaccinated group may improve public health outreach in subsequent waves of the current pandemic or for future pandemic planning. Using qualitative methods, we sought to explore the perceptions of COVID-19 risk, vaccine access, uptake and confidence among South Asians living in Canada. DESIGN: Semistructured interviews conducted with 25 participants analysed using thematic analysis. Throughout this process, we held frequent discussions with members of the study's advisory group to guide data collection (community engagement, recruitment and data analysis). SETTING: Communities of the GTHA and GVA with interviews conducted virtually over Zoom or telephone. PARTICIPANTS: 25 participants (15 from Ontario and 10 from British Columbia) were interviewed between July 2021 and January 2022. 10 individuals were community members, 9 were advocacy group leaders and 6 were public health staff. RESULTS: Access to and confidence in the COVID-19 vaccine was impacted by individual risk perceptions; sources of trusted information (ethnic and non-ethnic); impact of COVID-19 and the pandemic on individuals, families and society; and experiences with COVID-19 mandates and policies (including temporal and generational differences). Approaches that include community-level awareness and tailored outreach (language and cultural context) were considered successful. CONCLUSIONS: Understanding factors and developing strategies that build vaccine confidence and improve access can guide approaches that increase vaccine acceptance in the current and future pandemics.Visual abstract can be found at https://drive.google.com/file/d/1iXdnJj9ssc3hXCllZxP0QA9DhHH-7uwB/view.

The association of facility ownership with COVID-19 outbreaks in long-term care homes in British Columbia, Canada: a retrospective cohort study.

BACKGROUND: Long-term care (LTC) in Canada is delivered by a mix of government-, for-profit- and nonprofit-owned facilities that receive public funding to provide care, and were sites of major outbreaks during the early stages of the COVID-19 pandemic. We sought to assess whether facility ownership was associated with COVID-19 outbreaks among LTC facilities in British Columbia, Canada. METHODS: We conducted a retrospective observational study in which we linked LTC facility data, collected annually by the Office of the Seniors Advocate BC, with public health data on outbreaks. A facility outbreak was recorded when 1 or more residents tested positive for SARS-CoV-2 between Mar. 1, 2020, and Jan. 31, 2021. We used the Cox proportional hazards method to calculate the adjusted hazard ratio (HR) of the association between risk of COVID-19 outbreak and facility ownership, controlling for community incidence of COVID-19 and other facility characteristics. RESULTS: Overall, 94 outbreaks involved residents in 80 of 293 facilities. Compared with health authority-owned facilities, for-profit and nonprofit facilities had higher risks of COVID-19 outbreaks (adjusted HR 1.99, 95% confidence interval [CI] 1.12-3.52 and adjusted HR 1.84, 95% CI 1.00-3.36, respectively). The model adjusted for community incidence of infection (adjusted HR 1.12, 95% CI 1.07-1.17), total nursing hours per resident-day (adjusted HR 0.84, 95% CI 0.33-2.14), facility age (adjusted HR 1.01, 95% CI 1.00-1.02), number of facility beds (adjusted HR 1.20, 95% CI 1.12-1.30) and facilities with beds in shared rooms (adjusted HR 1.16, 95% CI 0.73-1.85). INTERPRETATION: Findings suggest that ownership of LTC facilities by health authorities in BC offered some protection against COVID-19 outbreaks. Further study is needed to unpack the underlying pathways behind this observed association.

Process description of developing HIV prevention monitoring indicators for a province-wide pre-exposure prophylaxis (PrEP) program in British Columbia, Canada.

In 2018, the pre-exposure prophylaxis (PrEP) program was initiated in British Columbia (BC), Canada, providing PrEP at no cost to qualifying residents. This observational study discussed the steps to develop key evidence-based monitoring indicators and their calculation using real-time data. The indicators were conceptualized, developed, assessed and approved by the Technical Monitoring Committee of representatives from five health authority regions in BC, the BC Ministry of Health, the BC Centre for Disease Control, and the BC Centre for Excellence in HIV/AIDS. Indicator development followed the steps adopted from the United States Centers for Disease Control and Prevention framework for program evaluation in public health. The assessment involved eight selection criteria: data quality, indicator validity, existing scientific evidence, indicator informativeness, indicator computing feasibility, clients' confidentiality maintenance capacity, indicator accuracy, and administrative considerations. Clients' data from the provincial-wide PrEP program (January 2018-December 2020) shows the indicators' calculation. The finalized 14 indicators included gender, age, health authority, new clients enrolled by provider type and by the health authority, new clients dispensed PrEP, clients per provider, key qualifying HIV risk factor(s), client status, PrEP usage type, PrEP quantity dispensed, syphilis and HIV testing and incident cases, and adverse drug reaction events. Cumulative clients' data (n = 6966; 99% cis-gender males) identified an increased new client enrollment and an unexpected drop during the COVID-19 pandemic. About 80% dispensed PrEP from the Vancouver Coastal health authority. The HIV incidence risk index for men who have sex with men score ≥10 was the most common qualifying risk factor. The framework we developed integrating indicators was applied to monitor our PrEP program, which could help reduce the public health impact of HIV.

Canadian SARS-CoV-2 serological survey using antenatal serum samples: a retrospective seroprevalence study.

BACKGROUND: Insufficient data on the rate and distribution of SARS-CoV-2 infection in Canada has presented a substantial challenge to the public health response to the COVID-19 pandemic. Our objective was to assess SARS-CoV-2 seroprevalence in a representative sample of pregnant people throughout Canada, across multiple time points over 2 years of the pandemic, to describe the seroprevalence and show the ability of this process to provide prevalence estimates. METHODS: This Canadian retrospective serological surveillance study used existing serological prenatal samples across 10 provinces over multiple time periods: Feb. 3-21, 2020; Aug. 24-Sept. 11, 2020; Nov. 16-Dec. 4, 2020; Nov. 15-Dec. 3, 2021; and results from the province of British Columbia during a period in which the SARS-CoV-2 B.1.1.529 (Omicron) variant was predominant, from Nov. 15, 2021, to June 11, 2022. Age and postal code administrative data allowed for comparison with concurrent polymerase chain reactivity (PCR)-positive results collected by Statistics Canada and the Canadian Surveillance of COVID-19 in Pregnancy (CANCOVID-Preg) project. RESULTS: Seropositivity in antenatal serum as early as February 2020 indicates SARS-CoV-2 transmission before the World Health Organization's declaration of the pandemic. Seroprevalence in our sample of pregnant people was 1.84 to 8.90 times higher than the recorded concurrent PCR-positive prevalence recorded among females aged 20-49 years in November-December 2020. Overall seropositivity in our sample of pregnant people was low at the end of 2020, increasing to 15% in 1 province by the end of 2021. Seroprevalence among pregnant people in BC during the Omicron period increased from 5.8% to 43% from November 2021 to June 2022. INTERPRETATION: These results indicate widespread vulnerability to SARS-CoV-2 infection before vaccine availability in Canada. During the time periods sampled, public health tracking systems were under-reporting infections, and seroprevalence results during the Omicron period indicate extensive community spread of SARS-CoV-2 infection.

Risk factors for COVID-19 hospitalization after COVID-19 vaccination: a population-based cohort study in Canada.

OBJECTIVES: With the uptake of COVID-19 vaccines, there is a need for population-based studies to assess risk factors for COVID-19-related hospitalization after vaccination and how they differ from unvaccinated individuals. METHODS: We used data from the British Columbia COVID-19 Cohort, a population-based cohort that includes all individuals (aged ≥18 years) who tested positive for SARS-CoV-2 by real-time reverse transcription-polymerase chain reaction from January 1, 2021 (after the start of vaccination program) to December 31, 2021. We used multivariable logistic regression models to assess COVID-19-related hospitalization risk by vaccination status and age group among confirmed COVID-19 cases. RESULTS: Of the 162,509 COVID-19 cases included in the analysis, 8,546 (5.3%) required hospitalization. Among vaccinated individuals, an increased odds of hospitalization with increasing age was observed for older age groups, namely those aged 50-59 years (odds ratio [OR] = 2.95, 95% confidence interval [CI]: 2.01-4.33), 60-69 years (OR = 4.82, 95% CI: 3.29, 7.07), 70-79 years (OR = 11.92, 95% CI: 8.02, 17.71), and ≥80 years (OR = 24.25, 95% CI: 16.02, 36.71). However, among unvaccinated individuals, there was a graded increase in odds of hospitalization with increasing age, starting at age group 30-39 years (OR = 2.14, 95% CI: 1.90, 2.41) to ≥80 years (OR = 41.95, 95% CI: 35.43, 49.67). Also, comparing all the age groups to the youngest, the observed magnitude of association was much higher among unvaccinated individuals than vaccinated ones. CONCLUSION: Alongside a number of comorbidities, our findings showed a strong association between age and COVID-19-related hospitalization, regardless of vaccination status. However, age-related hospitalization risk was reduced two-fold by vaccination, highlighting the need for vaccination in reducing the risk of severe disease and subsequent COVID-19-related hospitalization across all population groups.

Comparison of influenza and COVID-19 hospitalisations in British Columbia, Canada: a population-based study.

INTRODUCTION: We compared the population rate of COVID-19 and influenza hospitalisations by age, COVID-19 vaccine status and pandemic phase, which was lacking in other studies. METHOD: We conducted a population-based study using hospital data from the province of British Columbia (population 5.3 million) in Canada with universal healthcare coverage. We created two cohorts of COVID-19 hospitalisations based on date of admission: annual cohort (March 2020 to February 2021) and peak cohort (Omicron era; first 10 weeks of 2022). For comparison, we created influenza annual and peak cohorts using three historical periods years to capture varying severity and circulating strains: 2009/2010, 2015/2016 and 2016/2017. We estimated hospitalisation rates per 100 000 population. RESULTS: COVID-19 and influenza hospitalisation rates by age group were 'J' shaped. The population rate of COVID-19 hospital admissions in the annual cohort (mostly unvaccinated; public health restrictions in place) was significantly higher than influenza among individuals aged 30-69 years, and comparable to the severe influenza year (2016/2017) among 70+. In the peak COVID-19 cohort (mostly vaccinated; few restrictions in place), the hospitalisation rate was comparable with influenza 2016/2017 in all age groups, although rates among the unvaccinated population were still higher than influenza among 18+. Among people aged 5-17 years, COVID-19 hospitalisation rates were lower than/comparable to influenza years in both cohorts. The COVID-19 hospitalisation rate among 0-4 years old, during Omicron, was higher than influenza 2015/2016 and 2016/2017 and lower than 2009/2010 pandemic. CONCLUSIONS: During first Omicron wave, COVID-19 hospitalisation rates were significantly higher than historical influenza hospitalisation rates for unvaccinated adults but were comparable to influenza for vaccinated adults. For children, in the context of high infection levels, hospitalisation rates for COVID-19 were lower than 2009/2010 H1N1 influenza and comparable (higher for 0-4) to non-pandemic years, regardless of the vaccine status.

Impact of the COVID-19 pandemic on alcohol or drug use symptoms and service need among youth: a cross-sectional sample from British Columbia, Canada.

BACKGROUND: Concerns about youth alcohol and drug use have risen since the declaration of the global COVID-19 pandemic due to the pandemic's impact on known risk and protective factors for substance use. However, the pandemic's immediate and long-term impact on youths' substance use patterns has been less clear. Thus, this study sought to determine how the COVID-19 pandemic impacted alcohol or drug use and its risk and protective factors among youth accessing integrated youth services. METHODS: We conducted a repeated cross-sectional study of patient-reported outcomes data collected between May 2018 and February 2022 among youth (n = 6022) ages 10-24 accessing a provincial network of integrated youth services in Canada. The main exposure of interest was the COVID-19 pandemic (March 2020 - February 2022) compared with a pre-pandemic period (May 2018 - February 2020). As measured by the Global Appraisal of Individual Needs - Short Screener, outcomes included the average number of past month alcohol or drug use symptoms and past month likelihood of service need for alcohol/drug use (moderate/high vs. low need). Interrupted time series (ITS) examined change in average monthly alcohol/drug use symptoms between the pre- and pandemic periods. Stratified multivariable logistic regression investigated how the pandemic modified the effects of established risk/protective factors on likelihood of alcohol/drug use service need. RESULTS: Fifty-percent of youth met the criteria for moderate/high likelihood of alcohol/drug use service need, with the odds being 2.39 times (95% confidence interval = 2.04, 2.80) greater during the pandemic compared to the pre-pandemic period. Results from the ITS indicated significant immediate effects of the pandemic on monthly substance use symptoms (p = 0.01). Significant risk/protective factors for service need included exposure to violence, engagement in meaningful activities, and self-rated physical and mental health; and the direction of their effects remained consistent across pandemic and pre-pandemic periods. CONCLUSIONS: This study demonstrated that the COVID-19 pandemic corresponded with increased alcohol or drug use among youth accessing integrated services. This signals an urgent need for increased clinical capacity in existing youth services and policies that can respond to risk/protective factors for substance use earlier.

Clinical severity of Omicron subvariants BA.1, BA.2, and BA.5 in a population-based cohort study in British Columbia, Canada.

The SARS-CoV-2 variant Omicron emerged in late 2021. In British Columbia (BC), Canada, and globally, three genetically distinct subvariants of Omicron, BA.1, BA.2, and BA.5, emerged and became dominant successively within an 8-month period. SARS-CoV-2 subvariants continue to circulate in the population, acquiring new mutations that have the potential to alter infectivity, immunity, and disease severity. Here, we report a propensity-matched severity analysis from residents of BC over the course of the Omicron wave, including 39,237 individuals infected with BA.1, BA.2, or BA.5 based on paired high-quality sequence data and linked to comprehensive clinical outcomes data between December 23, 2021 and August 31, 2022. Relative to BA.1, BA.2 cases were associated with a 15% and 28% lower risk of hospitalization and intensive care unit (ICU) admission (aHRhospital = 1.17; 95% confidence interval [CI] = 1.096-1.252; aHRICU = 1.368; 95% CI = 1.152-1.624), whereas BA.5 infections were associated with an 18% higher risk of hospitalization (aHRhospital = 1.18; 95% CI = 1.133-1.224) after accounting for age, sex, comorbidities, vaccination status, geography, and social determinants of health. Phylogenetic analysis revealed no specific subclades associated with more severe clinical outcomes for any Omicron subvariant. In summary, BA.1, BA.2, and BA.5 subvariants were associated with differences in clinical severity, emphasizing how variant-specific monitoring programs remain critical components of patient and population-level public health responses as the pandemic continues.

Access to mental health support, unmet need and preferences among adolescents during the first year of the COVID-19 pandemic. / Accès à du soutien en santé mentale, besoins non comblés et préférences en la matière chez les adolescents au cours de la première année de la pandémie de COVID-19.

INTRODUCTION: The COVID-19 pandemic has had widespread effects on adolescent mental health. However, little is known about support-seeking, unmet need and preferences for mental health care among adolescents. METHODS: The Youth Development Instrument (YDI) is a school-administered survey of adolescents (N = 1928, mean age = 17.1, SD = 0.3) across British Columbia, Canada. In this cohort, we assessed the characteristics of accessed mental health supports, prevalence of unmet need and preferences for in-person versus internet-based services. RESULTS: Overall, 40% of adolescents obtained support for mental health, while 41% experienced unmet need. The most commonly accessed supports were family doctors or pediatricians (23.1%) and adults at school (20.6%). The most preferred mode of mental health care was in-person counselling (72.4%), followed by chat-based services (15.0%), phone call (8.1%) and video call (4.4%). The adjusted prevalence of accessing support was elevated among adolescents with anxiety (adjusted prevalence ratio [aPR] = 1.29, 95% CI: 1.10-1.51), those who used alcohol (1.14, 1.01-1.29), gender minorities (1.28, 1.03-1.58) and sexual minorities (1.28, 1.03-1.45). The adjusted prevalence of unmet need was elevated among adolescents with depression (1.90, 1.67-2.18), those with anxiety (1.78, 1.56-2.03), females (1.43, 1.31-1.58), gender minorities (1.45, 1.23-1.70) and sexual minorities (1.15, 1.07-1.23). CONCLUSION: Adolescents of gender or sexual minority status and those with anxiety were more likely than others to have discussed mental health concerns and also to have reported unmet need. The most common sources of support were primary health care providers and adults at school, while the most and least preferred modes of support were in-person and video call services, respectively.

Serial cross-sectional estimation of vaccine-and infection-induced SARS-CoV-2 seroprevalence in British Columbia, Canada.

BACKGROUND: The evolving proportion of the population considered immunologically naive versus primed for more efficient immune memory response to SARS-CoV-2 has implications for risk assessment. We sought to chronicle vaccine- and infection-induced seroprevalence across the first 7 waves of the COVID-19 pandemic in British Columbia, Canada. METHODS: During 8 cross-sectional serosurveys conducted between March 2020 and August 2022, we obtained anonymized residual sera from children and adults who attended an outpatient laboratory network in the Lower Mainland (Greater Vancouver and Fraser Valley). We used at least 3 immunoassays per serosurvey to detect SARS-CoV-2 spike and nucleocapsid antibodies. We assessed any seroprevalence (vaccineor infection-induced, or both), defined by positivity on any 2 assays, and infection-induced seroprevalence, also defined by dual-assay positivity but requiring both antinucleocapsid and antispike detection. We used estimates of infection-induced seroprevalence to explore underascertainment of infections by surveillance case reports. RESULTS: By January 2021, we estimated that any seroprevalence remained less than 5%, increasing with vaccine rollout to 56% by May-June 2021, 83% by September-October 2021 and 95% by March 2022. Infection-induced seroprevalence remained less than 15% through September-October 2021, increasing across Omicron waves to 42% by March 2022 and 61% by July-August 2022. By August 2022, 70%-80% of children younger than 20 years and 60%-70% of adults aged 20-59 years had been infected, but fewer than half of adults aged 60 years and older had been infected. Compared with estimates of infection-induced seroprevalence, surveillance case reports underestimated infections 12-fold between September 2021 and March 2022 and 92-fold between March 2022 and August 2022. INTERPRETATION: By August 2022, most children and adults younger than 60 years had evidence of both SARS-CoV-2 vaccination and infection. As previous evidence suggests that a history of both exposures may induce stronger, more durable hybrid immunity than either exposure alone, older adults - who have the lowest infection rates but highest risk of severe outcomes - continue to warrant prioritized vaccination.

Estimation of COVID-19 Period Prevalence and the Undiagnosed Population in Canadian Provinces: Model-Based Analysis.

BACKGROUND: The development of a successful COVID-19 control strategy requires a thorough understanding of the trends in geographic and demographic distributions of disease burden. In terms of the estimation of the population prevalence, this includes the crucial process of unravelling the number of patients who remain undiagnosed. OBJECTIVE: This study estimates the period prevalence of COVID-19 between March 1, 2020, and November 30, 2020, and the proportion of the infected population that remained undiagnosed in the Canadian provinces of Quebec, Ontario, Alberta, and British Columbia. METHODS: A model-based mathematical framework based on a disease progression and transmission model was developed to estimate the historical prevalence of COVID-19 using provincial-level statistics reporting seroprevalence, diagnoses, and deaths resulting from COVID-19. The framework was applied to three different age cohorts (< 30; 30-69; and ≥70 years) in each of the provinces studied. RESULTS: The estimates of COVID-19 period prevalence between March 1, 2020, and November 30, 2020, were 4.73% (95% CI 4.42%-4.99%) for Quebec, 2.88% (95% CI 2.75%-3.02%) for Ontario, 3.27% (95% CI 2.72%-3.70%) for Alberta, and 2.95% (95% CI 2.77%-3.15%) for British Columbia. Among the cohorts considered in this study, the estimated total number of infections ranged from 2-fold the number of diagnoses (among Quebecers, aged ≥70 years: 26,476/53,549, 49.44%) to 6-fold the number of diagnoses (among British Columbians aged ≥70 years: 3108/18,147, 17.12%). CONCLUSIONS: Our estimates indicate that a high proportion of the population infected between March 1 and November 30, 2020, remained undiagnosed. Knowledge of COVID-19 period prevalence and the undiagnosed population can provide vital evidence that policy makers can consider when planning COVID-19 control interventions and vaccination programs.

A Mixed-Methods Study of Risk Factors and Experiences of Health Care Workers Tested for the Novel Coronavirus in Canada.

OBJECTIVE: The aims of this study were to investigate occupational and non-work-related risk factors of coronavirus disease 2019 among health care workers (HCWs) in Vancouver Coastal Health, British Columbia, Canada, and to examine how HCWs described their experiences. METHODS: This was a matched case-control study using data from online and phone questionnaires with optional open-ended questions completed by HCWs who sought severe acute respiratory syndrome coronavirus 2 testing between March 2020 and March 2021. Conditional logistic regression and thematic analysis were utilized. RESULTS: Providing direct care to coronavirus disease 2019 patients during the intermediate cohort period (adjusted odds ratio, 1.90; 95% confidence interval, 1.04 to 3.46) and community exposure to a known case in the late cohort period (adjusted odds ratio, 3.595%; confidence interval, 1.86 to 6.83) were associated with higher infection odds. Suboptimal communication, mental stress, and situations perceived as unsafe were common sources of dissatisfaction. CONCLUSIONS: Varying levels of risk between occupational groups call for wider targeting of infection prevention measures. Strategies for mitigating community exposure and supporting HCW resilience are required.

Initial health care costs for COVID-19 in British Columbia and Ontario, Canada: an interprovincial population-based cohort study.

BACKGROUND: COVID-19 imposed substantial health and economic burdens. Comprehensive population-based estimates of health care costs for COVID-19 are essential for planning and policy evaluation. We estimated publicly funded health care costs in 2 Canadian provinces during the pandemic's first wave. METHODS: In this historical cohort study, we linked patients with their first positive SARS-CoV-2 test result by June 30, 2020, in 2 Canadian provinces (British Columbia and Ontario) to health care administrative databases and matched to negative or untested controls. We stratified patients by highest level of initial care: community, long-term care, hospital (without admission to the intensive care unit [ICU]) and ICU. Mean publicly funded health care costs for patients and controls, mean net (attributable to COVID-19) costs and total costs were estimated from 30 days before to 120 days after the index date, or to July 31, 2020, in 30-day periods for patients still being followed by the start of each period. RESULTS: We identified 2465 matched people with a positive test result for SARS-CoV-2 in BC and 28 893 in Ontario. Mean age was 53.4 (standard deviation [SD] 21.8) years (BC) and 53.7 (SD 22.7) years (Ontario); 55.7% (BC) and 56.1% (Ontario) were female. Net costs in the first 30 days after the index date were $22 010 (95% confidence interval [CI] 19 512 to 24 509) and $15 750 (95% CI 15 354 to 16 147) for patients admitted to hospital, and $65 828 (95% CI 58 535 to 73 122) and $56 088 (95% CI 53 721 to 58 455) for ICU patients in BC and Ontario, respectively. In the community and long-term care settings, net costs were near 0. Total costs for all people, from 30 days before to 30 days after the index date, were $22 128 330 (BC) and $175 778 210 (Ontario). INTERPRETATION: During the first wave, we found that mean costs attributable to COVID-19 were highest for patients with ICU admission and higher in BC than Ontario. Reducing the number of people who acquire COVID-19 and severity of illness are required to mitigate the economic impact of COVID-19.