With the help of the medical records of more than 1,000 health care workers interacting directly with patients, researchers have concluded that medical masks provide little benefit over N95 respirators.
Specifically, researchers said, “The primary outcome in the intention-to-treat analysis, RT-PCR–confirmed COVID-19, occurred in 52 of 497 (10.46%) in the medial mask group versus 47 of 507 (9.27%) in the N95 respirator group (HR, 1.14 [95% CI, 0.77 to 1.69]).”
In subgroups of the study group, such as Egypt, they did note that “there was a close to null effect of medical masks compared with N95 respirators,” saying, “It is possible that a higher rate of community transmission could have obscured a higher rate of infection with the medical mask versus the N95 respirators …
It is also possible that given the high rate of exposure to patients with COVID-19 reported by health care workers in Egypt with the more transmissible Omicron, the results reflect no difference between the groups in health care acquisition of RT-PCR–confirmed COVID-19.”
SOURCE:
Annals of Internal Medicine November 29, 2022