COVID-19 Evidence Alerts
from McMaster PLUSTM

Current best evidence for clinical care (more info)

Prognosis Chou R, Dana T, Buckley DI, et al. Epidemiology of and Risk Factors for Coronavirus Infection in Health Care Workers: A Living Rapid Review. Ann Intern Med. 2020 Jul 21;173(2):120-136. doi: 10.7326/M20-1632. Epub 2020 May 5.

BACKGROUND: Health care workers (HCWs) are at risk for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.

PURPOSE: To examine the burden of SARS-CoV-2, SARS-CoV-1, and Middle East respiratory syndrome (MERS)-CoV on HCWs and risk factors for infection, using rapid and living review methods.

DATA SOURCES: Multiple electronic databases, including the WHO database of publications on coronavirus disease and the medRxiv preprint server (2003 through 27 March 2020, with ongoing surveillance through 24 April 2020), and reference lists.

STUDY SELECTION: Studies published in any language reporting incidence of or outcomes associated with coronavirus infections in HCWs and studies on the association between risk factors (demographic characteristics, role, exposures, environmental and administrative factors, and personal protective equipment [PPE] use) and HCW infections. New evidence will be incorporated on an ongoing basis by using living review methods.

DATA EXTRACTION: One reviewer abstracted data and assessed methodological limitations; verification was done by a second reviewer.

DATA SYNTHESIS: 64 studies met inclusion criteria; 43 studies addressed burden of HCW infections (15 on SARS-CoV-2), and 34 studies addressed risk factors (3 on SARS-CoV-2). Health care workers accounted for a significant proportion of coronavirus infections and may experience particularly high infection incidence after unprotected exposures. Illness severity was lower than in non-HCWs. Depression, anxiety, and psychological distress were common in HCWs during the coronavirus disease 2019 outbreak. The strongest evidence on risk factors was on PPE use and decreased infection risk. The association was most consistent for masks but was also observed for gloves, gowns, eye protection, and handwashing; evidence suggested a dose-response relationship. No study evaluated PPE reuse. Certain exposures (such as involvement in intubations, direct patient contact, or contact with bodily secretions) were associated with increased infection risk. Infection control training was associated with decreased risk.

LIMITATION: There were few studies on risk factors for SARS-CoV-2, the studies had methodological limitations, and streamlined rapid review methods were used.

CONCLUSION: Health care workers experience significant burdens from coronavirus infections, including SARS-CoV-2. Use of PPE and infection control training are associated with decreased infection risk, and certain exposures are associated with increased risk.

PRIMARY FUNDING SOURCE: World Health Organization.

Discipline / Specialty Area Score
Hospital Doctor/Hospitalists
Internal Medicine
Family Medicine (FM)/General Practice (GP)
Emergency Medicine
General Internal Medicine-Primary Care(US)
Occupational and Environmental Health
Public Health
Infectious Disease
Intensivist/Critical Care
Comments from MORE raters

Emergency Medicine rater

Limited evidence exists specific to COVID-19 infection, no granular details on EM, and conclusions (e.g., cohorting patients, PPE, hand-washing, etc are critical) already implemented. There is already widespread recognition in EM of the mental health effects of isolation, high-risk work (intubation and other aerosolized procedures), and the severity of the disease (high mortality). This "living" review may become more important with emerging COVID-19 evidence.

General Internal Medicine-Primary Care(US) rater

This article was published on May 5th. It's an excellent study with a few studies on risk factors for SARS- CoV-2, with methodological limitations, and they generally use the rapid evidence review method, perfect for quick decision making and fast fact checking. The study has limitations, from potential recall, selection, or participation bias to issues regarding evaluation of outcomes. The first studies early in the outbreak when case numbers were increasing sharply, showed that HCW positive cases were formed by one third of cases from physicians and two thirds were nurses; Neuro symptoms study is harder, since there is not baseline symptom information. The important points are that education and training in infection control measures were consistently associated with decreased risk for HCW infections. The most important point in the article is the conclusion that infections on healthcare workers must be maintained at a minimum to maintain health system capacity.

Internal Medicine rater

Although the information about incidence was varied, the information about PPE use was relevant. Some of it was in direct conflict to what we had been advised by the “PPE police” while on the COVID wards.

Occupational and Environmental Health rater

The study is rigorous and absolutely promising, but it represents only a first step in an ongoing process, which leaves open most of the important questions.

Occupational and Environmental Health rater

This is useful information, and although many in the field may already be aware, it is useful to have it consolidated in one place with an extensive reference list.

Public Health rater

It is important to read such a topic in this COVID outbreak, but it would’ve been easier to read if it was a short meta analysis rather a systemic review.