This is a randomized clinical trial
This cluster randomized clinical trial compares the effect of N95 respirators vs medical masks worn by health care personnel for prevention of workplace-acquired influenza and other viral respiratory infections in geographically diverse, high-exposure outpatient settings.
jamanetwork.com
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Question
Is the use of N95 respirators or medical masks more effective in preventing influenza infection among outpatient health care personnel in close contact with patients with suspected respiratory illness?"
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Findings In this pragmatic, cluster randomized clinical trial involving 2862 health care personnel, there was no significant difference in the incidence of laboratory-confirmed influenza among health care personnel with the use of N95 respirators (8.2%) vs medical masks (7.2%).
Meaning As worn by health care personnel in this trial, use of N95 respirators, compared with medical masks, in the outpatient setting resulted in no significant difference in the rates of laboratory-confirmed influenza."