Medical Masks versus N95 Respirators to Prevent COVID-19 in Healthcare Workers: A Randomized Trial

Little is known about the effectiveness of respiratory protective devices in protecting healthcare workers from 2019 novel coronavirus disease (COVID-19). Epidemiologic data to support the superiority of an N95 respirator, preferentially recommended by U.S CDC and European CDC for prevention for COVID-19, over the less expensive and readily available medical mask, are sparse. In contrast, the World Health Organization and the Public Health Agency of Canada (PHAC) recommend use of a medical mask for the routine care of patients with COVID-19. As the pandemic has evolved, a serious concern has been that there is not a sufficient stockpile of N95 respirators available for aerosol generating procedures. Moreover, compliance with N95 respirators could overtime decrease as they have been associated with headaches and discomfort. This could lead to a lack of compliance, which during SARS increased the risk of infection. Although for aerosol generating procedures, N95 respirators are the preferred method of protection, for non-aerosol generating patient care, it is not clear that N95 respirators offer greater protection than medical masks based on the two small existing observational studies that addressed this. Furthermore, the requirement for fit testing may be a barrier in low and middle-income countries. It is therefore of prime importance during this pandemic to conduct a head-to-head comparison of medical masks and N95 respirators. For this reason, we propose a randomized controlled trial in which healthcare workers in healthcare facilities in three provinces will be randomized to either medical masks or N95 respirators when providing care to patients with COVID-19. We will detect confirm COVID-19 in both groups. We hypothesize that medical masks offer similar protection for routine care than N95 respirators for COVID-19.