A national atlas to improve the study of Canadians living with long COVID (post-COVID-19 condition).

Objectives: To develop a national atlas of (1) Canadian cohorts studying or with the potential to study adults living with long COVID (LC) and (2) harmonize provincial and territorial administrative datasets to facilitate the creation of validated case-ascertainment algorithms and foster national collaboration on LC research.

Methods: We conducted a multifaceted environmental scan that included a comprehensive literature search and a survey of members of Canada's national LC research network between August 21, 2023, and November 10, 2023. We identified provincial and territorial cohorts, including those that were linkable to administrative data and common data elements among administrative datasets.

HBV Care Cascade in Rwanda: A Population-based Study From 2016-2023.

Introduction: In sub-Saharan Africa, data on the hepatitis B virus (HBV) care cascade are limited. We assessed Rwanda's HBV care cascade.

Methods: We analyzed data from the District Health Information System 2, capturing 4.

COVID-19 vaccine uptake and effectiveness among people with recent history of injection drug use in British Columbia, Canada: A retrospective analysis.

Background: It is a public health priority to assess vaccine impact in marginalized populations disproportionately affected by COVID-19 to inform population-specific policies and reduce health disparities. We assessed COVID-19 vaccine uptake and effectiveness among people who inject drugs (PWID) in British Columbia, Canada.

Methods: We used a population-based, linked data platform and a validated algorithm with high specificity to create a cohort of people aged 18-65 years with recent history of injection drug use (PWID).

Global disparities in access to hepatitis C medicines before and during the early phase of the COVID-19 pandemic: an ARIMA-based interrupted time series analysis.

Background: The introduction of direct-acting antivirals (DAAs) has allowed countries to reduce the health and economic burden of hepatitis C virus (HCV). However, access to DAAs remains expensive and limited in many countries globally due to wide disparities in HCV drug pricing. We assessed how global use of HCV drugs has changed over time and the effect that COVID-19 might have had on DAA utilisation.

Direct-Acting Antivirals and Risk of Hepatitis C Extrahepatic Manifestations.

Importance: Hepatitis C virus (HCV) infection is associated with various extrahepatic manifestations (EHMs) that can significantly impact patients' quality of life and overall health outcomes.

Objective: To assess the association between successful direct-acting antiviral (DAA) treatment and the risk of EHMs in individuals with chronic HCV infection.

Design, Setting, And Participants: This population-based retrospective cohort study used data from 1990 to 2021, with a median follow-up of 2.

Risk of Guillain-Barré syndrome after COVID-19 vaccination or SARS-CoV-2 infection: A multinational self-controlled case series study.

Background: The association between Guillain-Barré syndrome (GBS) and certain COVID-19 vaccines is inconclusive. We investigated the risk of GBS after COVID-19 vaccination or SARS-CoV-2 infection.

Methods: Using a common protocol, we conducted a self-controlled case series study from 1 December 2020 to 9 August 2023 at 20 global sites within the Global Vaccine Data Network™ (GVDN®).

Work Productivity Loss in People Living With Long COVID Symptoms Over 2 Years From Infection.

Objective: To evaluate the work productivity loss in people experiencing long COVID symptoms more than 2 years after infection.

Methods: In a cross-sectional study, employed adults from British Columbia, Canada, who had a polymerase chain reaction-confirmed SARS-CoV-2 infection more than 2 years earlier, completed an online survey incorporating the Valuation of Lost Productivity questionnaire. Long COVID status was self-reported.

Impact of the COVID-19 Pandemic and Control Measures on Screening and Diagnoses of Type 2 Diabetes in British Columbia.

Introduction: In British Columbia (BC), Canada, COVID-19 and associated control measures impacted routine care for patients with diabetes. Some of these measures may have impacted timely screening and diagnosis of type 2 diabetes. We assessed the impact of control measures on screening and diagnosis of type 2 diabetes in BC.

Health-related adverse work outcomes associated with post COVID-19 condition: a cross-sectional study.

Introduction: Symptoms from post COVID-19 condition (PCC) can impair functioning in working-age adults. However, there is uncertainty about the relationship between PCC and work outcomes. This study aimed to assess health-related adverse work outcomes in individuals with a PCC history compared with others who had COVID-19.

Long COVID Discourse in Canada, the United States, and Europe: Topic Modeling and Sentiment Analysis of Twitter Data.

Background: Social media serves as a vast repository of data, offering insights into public perceptions and emotions surrounding significant societal issues. Amid the COVID-19 pandemic, long COVID (formally known as post-COVID-19 condition) has emerged as a chronic health condition, profoundly impacting numerous lives and livelihoods. Given the dynamic nature of long COVID and our evolving understanding of it, effectively capturing people's sentiments and perceptions through social media becomes increasingly crucial.

Healthcare utilization among COVID-19 mRNA vaccine-associated myocarditis cases: a matched retrospective cohort study.

Objectives: We evaluated all-cause healthcare utilization among those with vaccine-associated myocarditis, compared to vaccinees without postvaccination myocarditis.

Methods: We conducted a retrospective cohort study in individuals aged 12 and older who received COVID-19 mRNA vaccination in British Columbia. Exposure was defined as an ED visit or hospitalization for myocarditis within 21 days postvaccination.

Coronavirus disease 2019 outcomes in a population-based cohort of people with HIV and a matched cohort of people without HIV during Omicron variant waves.

We found that rates of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) testing and reverse transcriptase (RT)-PCR-confirmed infection were approximately 50% higher in a population-based cohort of people with HIV compared with a matched cohort of people without HIV during the Omicron era (2 January 2022 to 31 March 2023) in Ontario, Canada, after controlling for age, sex, residential census tract, and country of birth. Rates of coronavirus disease 2019 (COVID-19)-related hospitalization and/or death were more than double. Differences persisted independent of vaccination, healthcare access, and COVID-19 diagnosis.

The Clinical Severity of COVID-19 Variants of Concern: Retrospective Population-Based Analysis.

Background: SARS-CoV-2 variants of concern (VOCs) emerged and rapidly replaced the original strain worldwide. The increased transmissibility of these new variants led to increases in infections, hospitalizations, and mortality. However, there is a scarcity of retrospective investigations examining the severity of all the main VOCs in presence of key public health measures and within various social determinants of health (SDOHs).

The mediating role of SARS-CoV-2 variants between income and hospitalization due to COVID-19: a period-based mediation analysis.

The mechanisms facilitating the relationship between low income and COVID-19 severity have not been partitioned in the presence of SARS-CoV-2 variants of concern (VOCs). To address this, we used causal mediation analysis to quantify the possible mediating role infection with VOC has on the relationship between neighborhood income (exposure) and hospitalization due to COVID-19 among cases (outcome). A population-based cohort of 65 629 individuals residing in British Columbia, Canada, was divided into 3 periods of VOC co-circulation in the 2021 calendar year, whereby each period included co-circulation of an emerging and an established VOC.

Association of hepatitis B virus treatment with all-cause and liver-related mortality among individuals with HBV and cirrhosis: a population-based cohort study.

Background: We evaluated the association of hepatitis B virus (HBV) treatment with all-cause, and liver-related mortality among individuals with HBV and cirrhosis in British Columbia (BC), Canada.

Methods: This analysis included people diagnosed with HBV and had cirrhosis in the BC Hepatitis Testers Cohort, including data on all individuals diagnosed with HBV from 1990 to 2015 in BC and integrated with healthcare administrative data. We followed people with cirrhosis from the first cirrhosis diagnosis date until death or December 31, 2020.

Impact of COVID-19 pandemic on hepatocellular carcinoma surveillance in British Columbia, Canada: An interrupted time series study.

We assessed the impact of the COVID-19 pandemic on hepatocellular carcinoma (HCC) surveillance among individuals with HCV diagnosed with cirrhosis in British Columbia (BC), Canada. We used data from the British Columbia Hepatitis Testers Cohort (BC-HTC), including all individuals in the province tested for or diagnosed with HCV from 1 January 1990 to 31 December 2015, to assess HCC surveillance. To analyse the impact of the pandemic on HCC surveillance, we used pre-policy (January 2018 to February 2020) and post-policy (March to December 2020) periods.

Long-Term Health-Related Quality of Life in Working-Age COVID-19 Survivors: A Cross-Sectional Study.

Background: Most working-age (18-64) adults have been infected with SARS-CoV-2, and some may have developed post-COVID-19 condition (PCC). However, long-term health-related quality of life (HRQOL) following infection remains uncharacterized.

Methods: In this cross-sectional study, COVID-19 survivors from throughout British Columbia (BC), Canada, completed a questionnaire >2 years after infection.

Impact of the COVID-19 Pandemic on Hepatitis C Treatment Initiation in British Columbia, Canada: An Interrupted Time Series Study.

We investigated the impacts of the COVID-19 pandemic on hepatitis C (HCV) treatment initiation, including by birth cohort and injection drug use status, in British Columbia (BC), Canada. Using population data from the BC COVID-19 Cohort, we conducted interrupted time series analyses, estimating changes in HCV treatment initiation following the introduction of pandemic-related policies in March 2020. The study included a pre-policy period (April 2018 to March 2020) and three follow-up periods (April to December 2020, January to December 2021, and January to December 2022).

Risk of Major Adverse Cardiovascular Events After SARS-CoV-2 Infection in British Columbia: A Population-Based Study.

Background: COVID-19 is associated with increased risk of post-acute cardiovascular outcomes. Population-based evidence for long periods of observation is still limited.

Methods: This population-based cohort study was conducted using data (2020-2021) from the British Columbia COVID-19 Cohort.

Risk of Severe COVID-19-Related Outcomes among Patients with Cirrhosis: A Population-Based Cohort Study in Canada.

We assessed the association between cirrhosis and severe COVID-19-related outcomes among people with laboratory-diagnosed COVID-19 infection in British Columbia, Canada. We used data from the British Columbia (BC) COVID-19 Cohort, a population-based cohort that integrates data on all individuals tested for COVID-19, with data on hospitalizations, medical visits, emergency room visits, prescription drugs, chronic conditions, and deaths in the Canadian province of BC. We included all individuals aged ≥18 who tested positive for SARS-CoV-2 by real-time reverse transcription-polymerase chain reaction from 1 January 2021 to 31 December 2021.

Validation of case-ascertainment algorithms using health administrative data to identify people who inject drugs in Ontario, Canada.

Objectives: Health administrative data can be used to improve the health of people who inject drugs by informing public health surveillance and program planning, monitoring, and evaluation. However, methodological gaps in the use of these data persist due to challenges in accurately identifying injection drug use (IDU) at the population level. In this study, we validated case-ascertainment algorithms for identifying people who inject drugs using health administrative data in Ontario, Canada.

Visible minority status and occupation were associated with increased COVID-19 infection in Greater Vancouver British Columbia between June and November 2020: an ecological study.

Background: The COVID-19 pandemic has highlighted health disparities, especially among specific population groups. This study examines the spatial relationship between the proportion of visible minorities (VM), occupation types and COVID-19 infection in the Greater Vancouver region of British Columbia, Canada.

Methods: Provincial COVID-19 case data between June 24, 2020, and November 7, 2020, were aggregated by census dissemination area and linked with sociodemographic data from the Canadian 2016 census.

Cohort profile: the British Columbia COVID-19 Cohort (BCC19C)-a dynamic, linked population-based cohort.

Purpose: The British Columbia COVID-19 Cohort (BCC19C) was developed from an innovative, dynamic surveillance platform and is accessed/analyzed through a cloud-based environment. The platform integrates recently developed provincial COVID-19 datasets (refreshed daily) with existing administrative holdings and provincial registries (refreshed weekly/monthly). The platform/cohort were established to inform the COVID-19 response in near "real-time" and to answer more in-depth epidemiologic questions.