The availability, use and impact of workplace mental health supports during the COVID-19 pandemic in a Canadian prospective cohort of healthcare workers. (preprint)

Purpose The COVID-19 pandemic focused attention on workplace mental health (MH) supports for healthcare workers (HCWs). Methods HCWs in a Canadian cohort reported availability and use of workplace MH supports in October 2020, April 2021 and 2022. At recruitment (April-October 2020) they reported pre-pandemic MH. They completed the Hospital Anxiety and Depression Scale (HADS) at each contact. Availability and use of supports were examined by pandemic phase, workplace, work role and, for use, gender, age, pre-pandemic and current MH. Impact was assessed as MH in 2021/2022 following use in 2020. Results Reports of availability, use and HADS scores were obtained from 4400 HCWs working with patients. Access to MH supports increased during the pandemic, with 94% reporting access to some workplace support by 2022. Half the HCWs had at least one clinically significant HADS score during the pandemic. The proportion with high anxiety scores decreased from 29% to 24% as the pandemic progressed: proportions with high depression scores remained close to 10%. Those with a history of pre-pandemic or current mental ill-health formed the majority of HCWs using MH supports. 25% of those with high HADS scores did not use supports, with depressed males least likely to report use. HCWs using an Employment Assistance Program at the 2nd contact had lower HADS scores at next follow-up but this was not sustained. Conclusion HCWs reported increasing availability and use of MH supports as the pandemic progressed but one in four of those with anxiety and, particularly, depression did not seek support.

Determinants of SARS-CoV-2 IgG response and decay in Canadian healthcare workers: a prospective cohort study. (preprint)

Introduction Healthcare workers (HCWs) from an interprovincial Canadian cohort were asked to give serial blood samples to identify factors associated with anti-receptor binding domain (anti-RBD) IgG response to the SARS-CoV-2 virus. Methods Members of the HCW cohort donated blood samples four months after their first SARS-CoV-2 immunization and again at 7, 10 and 13 months. Date and type of immunizations and dates of SARS-CoV-2 infection were collected at each of four contacts, together with information on immunologically-compromising conditions and current therapies. Blood samples were analyzed centrally for anti-RBD IgG and anti-nucleocapsid IgG (Abbott Architect, Abbott Diagnostics). Records of immunization and SARS-CoV-2 testing from public health agencies were used to assess the impact of reporting errors on estimates from the random-effects multivariable model fitted to the data. Results 2752 of 4567 vaccinated cohort participants agreed to donate at least one blood sample. Modelling of anti-RBD IgG titer from 8903 samples showed an increase in IgG with each vaccine dose and with first infection. A decrease in IgG titer was found with the number of months since vaccination or infection, with the sharpest decline after the third dose. An immunization regime that included mRNA1273 (Moderna) resulted in higher anti-RBD IgG. Participants reporting multiple sclerosis, rheumatoid arthritis or taking selective immunosuppressants, tumor necrosis factor inhibitors, calcineurin inhibitors and antineoplastic agents had lower anti-RBD IgG. Supplementary analyses showed higher anti-RBD IgG in those reporting side-effects of vaccination, no relation of anti-RBD IgG to obesity and lower titers in women immunized early in pregnancy. Sensitivity analysis results suggested no important bias in the self-report data. Conclusion Creation of a prospective cohort was central to the credibility of results presented here. Serial serology assessments, with longitudinal analysis, provided effect estimates with enhanced accuracy and a clearer understanding of medical and other factors affecting response to vaccination.

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 (preprint)

Objectives To investigate changes in risk of infection and mental distress in healthcare workers (HCWs) relative to the community as the Covid-19 pandemic progressed. Methods HCWs in Alberta, Canada, recruited to an interprovincial cohort were asked consent to link to Alberta's administrative health database (AHDB) ) and to information on Covid-19 immunization and polymerase chain reaction (PCR) testing. Those consenting were matched to records of up to 5 community referents (CRs). Physician diagnoses of Covid-19 were identified in the AHDB from the start of the pandemic to 31 March 2022. Physician consultations for mental health (MH) conditions (anxiety, stress/adjustment reaction, depressive) were identified from 1 April 2017 to 31 March 2022. Relative risk for HCWs was estimated for each condition, overall and for successive infection waves. Results. 80% (3050/3812) of HCWs consented to be linked to the AHDB: 97% (2959/3050) were matched to 14546 CRs. HCWs were at greater risk of Covid-19 overall, with first infection defined either from PCR tests or physician records They were also at increased risk for each of the three MH diagnoses. In analyses adjusted for confounding, risk of Covid-19 infection was higher than CRs early in the pandemic and during the fifth (Omicron) wave. The excess risk of stress/adjustment reactions and depressive conditions increased with successive waves during the epidemic, peaking in the 4th wave. Conclusion Administrative health data, although not a complete reflection of infection or MH, contributed to an understanding of changing risk over time, with excess risk continuing late in the pandemic

Cohort profile: Recruitment and retention in a prospective cohort of Canadian health care workers during the Covid-19 pandemic. (preprint)

Purpose Health care workers (HCWs) 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. Participants Participants were recruited from four Canadian provinces, physicians (MDs) in Alberta, British Columbia, Ontario and Quebec, registered nurses (RNs), licensed practical nurses (LPNs) and health care 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 4 referents in a nested case-referent study. Findings to Date 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. Pre-pandemic risk factors for mental ill-health and respiratory illness differed markedly by occupation. Participants completed questionnaires at recruitment, fall 2020, spring 2021, and spring 2022. By the 4th contact, 127 had retired, moved away or died, for a response rate of 89% (4299/4837). 4567/4864 (92%) received at least one vaccine shot: 2752/4567 (60%) gave post-vaccine 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 Plans Serology results (concentration of immunoglobulin G (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 sequalae 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.