Cohort profile: recruitment and retention in a prospective cohort of Canadian healthcare workers during the COVID-19 pandemic

Abstract

PurposeHealthcare workers were recruited early in 2020 to chart effects on their health as the COVID-19 pandemic evolved. The aim was to identify modifiable workplace risk factors for infection and mental ill health.ParticipantsParticipants were recruited from four Canadian provinces, physicians (medical doctors, MDs) in Alberta, British Columbia, Ontario and Quebec, registered nurses (RNs), licensed practical nurses (LPNs) and healthcare aides (HCAs) in Alberta and personal support workers (PSWs) in Ontario. Volunteers gave blood for serology testing before and after vaccination. Cases with COVID-19 were matched with up to four referents in a nested case-referent study.Findings to dateOverall, 4964/5130 (97%) of those recruited joined the longitudinal cohort: 1442 MDs, 3136 RNs, 71 LPNs, 235 PSWs, 80 HCAs. Overall, 3812 (77%) were from Alberta. Prepandemic risk factors for mental ill health and respiratory illness differed markedly by occupation. Participants completed questionnaires at recruitment, fall 2020, spring 2021, spring 2022. By 2022, 4837 remained in the cohort (127 had retired, moved away or died), for a response rate of 89% (4299/4837). 4567/4964 (92%) received at least one vaccine shot: 2752/4567 (60%) gave postvaccine blood samples. Ease of accessing blood collection sites was a strong determinant of participation. Among 533 cases and 1697 referents recruited to the nested case-referent study, risk of infection at work decreased with widespread vaccination.Future plansSerology results (concentration of IgG) together with demographic data will be entered into the publicly accessible database compiled by the Canadian Immunology Task Force. Linkage with provincial administrative health databases will permit case validation, investigation of longer-term sequelae of infection and comparison with community controls. Analysis of the existing dataset will concentrate on effects on IgG of medical condition, medications and stage of pregnancy, and the role of occupational exposures and supports on mental health during the pandemic.

Excess risk of COVID-19 infection and mental distress in healthcare workers during successive pandemic waves: Analysis of matched cohorts of healthcare workers and community referents in Alberta, Canada

“…Further weaknesses lie in the response rate of HCWs to join the cohort (at best around 15% of those approached (Cherry et al, 2023b )) and the unwillingness of 20% (752 participants) to give consent to data linkage at the time of recruitment. Those who took part may not be representative of HCWs in Alberta or, indeed, of HCWs elsewhere.…”

“…HCWs were recruited from four Canadian provinces (Alberta, British Columbia, Ontario, and Quebec) during the early months of the pandemic and followed up through periodic questionnaires to the summer of 2022 (Cherry et al, 2023b ). Participants from Alberta were asked at recruitment for consent to match their individual records to the Alberta Administrative Health Database (AHDB).…”

Work characteristics, workplace support and mental ill-health in a Canadian cohort of healthcare workers during the COVID-19 pandemic

“…Healthcare workers were recruited from four Canadian provinces (Alberta, British Columbia, Ontario, and Quebec) close to the start of the pandemic and followed for 24 months. 9 Healthcare workers were approached through their professional organizations within each province. Physicians (MDs) were recruited from Alberta, British Columbia, Ontario, and Quebec, registered nurses (RNs) and registered psychiatric nurses (RNs), licensed practical nurses (LPNs) and healthcare aides (HCAs) just from Alberta, and personal support workers (PSWs) just from Ontario.…”

“…5,6 Anticipating increased risk of infection in HCWs 7 and transient or longer-term mental health disturbances, 8 we set up a cohort of HCWs early in the pandemic to identify workplace factors associated with risk of infection or with new-onset poor mental health. 9 As we could not observe directly, we relied on reports from the HCWs about their workplace and practices and their confidence in working with patients with COVID-19, their worries about working through the pandemic and where they were finding support. We sought to understand how workplace perceptions related to mental health, having accounted for other factors, particularly work with infected patients, and to consider whether mental health supports reported to be provided by the employer were related either to perceptions of support or to mental health.…”