A randomized controlled trial in which health care workers will be randomized to either medical masks or N95 respirators when providing medical care to patients with COVID-19. This multi-centre randomized controlled trial will assess whether medical masks are non-inferior to N95 respirators when health care workers provide care involving non-aerosol generating procedures. Health care workers will be randomized to either use of a medical mask or to a fit-tested N95 respirator when providing care for patients with febrile respiratory illness. Health care workers randomly assigned to the N95 respirator group will be instructed to use a fit-tested National Institute for Occupational Safety and Health-approved N95 respirator when providing routine care to patients with COVID-19 or suspected COVID-19. Participants will use the type of device they were allocated to, either a medical mask or an N95 respirator, for 10 weeks, however, health care workers can also use the N95 respirator at any time based on a point-of-care risk assessment. Universal masking is the policy implemented at each study site. Extended and re-use of N95 respirators will be permitted if the local situation requires it. The primary outcome is laboratory confirmed RT-PCR COVID-19 among participants.~A nasopharyngeal swab will be obtained if any one of the following symptoms or signs is present: fever (≥38 C), cough, or shortness of breath, or if 2 of the following are present: fatigue, myalgia, headache, dizziness, expectoration, sore throat, diarrhea, nausea, vomiting, abdominal pain, runny nose, altered taste or smell, conjunctivitis, or painful swallowing.~Participants that receive a COVID-19 vaccine after enrollment with efficacy of > 50% for the circulating strain will continue to be followed until 2 weeks after the first dose of the vaccine. All other participants will be followed for 10 weeks.~Self-reporting of hand hygiene and the use of external monitors, where feasible, will be used to collect basic hand hygiene data.~The sample size is 1,010 participants. This will allow 90% power at an alpha (one sided) of 0.05 and to account for participants who may not have completed 10 weeks because of COVID-19 mRNA vaccination.~Changes made to the protocol prior to May 4, 2020, which was prior to the start of enrollment:~Eligibility criteria expanded from nurses who provide direct patient care to health care workers that provide direct patient care.~Allowed extended and re-use of N95 respirators if the local situation required it.~Added self-reporting of hand hygiene and the use of external monitors if feasible.~Reduced the duration of follow up from 12 weeks to 10 weeks~Changes made on or after May 4, 2020:~Expanded the criteria for the requirement of swabs to detect COVID-19 by adding runny nose, altered taste or smell, and conjunctivitis and also asked for a swab for fever, cough, or shortness of breath alone OR for two of the previously listed symptoms or signs (May 19, 2020).~Added previously known COVID infection as an exclusion (October, 30, 2020).~Added receipt of a COVID-19 vaccine with efficacy of > 50% as an exclusion (October 30, 2020).~Allowed those participants that received a COVID-19 vaccine after enrollment with efficacy of > 50% for the circulating strain to continue to be followed until 2 weeks after the first dose of the vaccine (December 17, 2020).~Increased the sample size to 1,010 participants to allow 90% power at an alpha (one sided) of 0.05 and to account for participants who may not have completed 10 weeks because of COVID-19 mRNA vaccination (July 26, 2021).~Added wording to capture implementation since May 4th, 2020, Where the policy of the healthcare setting has been universal use of a facemask, that is wearing a facemask at all times when in the hospital, then the facemask participants were randomized to will be used. (December 27, 2021)
A randomized controlled trial in which health care workers will be randomized to either medical masks or N95 respirators when providing care to patients with COVID-19.