Abstract 1: N95 Respirators vs Medical Masks for Preventing Flu Among Health Care Workers

There are many opinions out there and very little data or high-quality information to inform those opinions.

Here are some other studies discussing masks in preventing influenza spread (Not COVID19)

Loeb et al 2009 did a non-inferiority trial of surgical masks vs. N95 respirator masks for preventing flu in Ontario nurses working at tertiary care hospitals. They concluded surgical masks were non-inferior.

MacIntyre et al 2009 did a cluster RCT on the use of face masks to control for respiratory virus transmission in households. They found face masks were unlikely to be an effective policy for seasonal respiratory diseases. This was in part because <50% of participants had mask adherence. Those who wore the mask did have a statistically significant reduction in clinical infection.

MacIntyre et al 2011 published another study in the same year comparing efficacy non-face masks to fit tested and non-fit tested N95 respiratory mask in preventing respiratory infections in hospital workers in China. The results showed a significant decrease in respiratory illnesses including influenza. The authors did cautioned readers that the trial may have been underpowered.

Smith et al CMAJ 2016 did a systematic review and meta-analysis on this topic. The authors concluded: “Although N95 respirators appeared to have a protective advantage over surgical masks in laboratory settings, our meta-analysis showed that there were insufficient data to determine definitively whether N95 respirators are superior to surgical masks in protecting health care workers against transmissible acute respiratory infections in clinical settings.”