Their own study admitted to -only- analyzing 34 incidents of the flu during the study! — THIS IS NOT A SCIENTIFIC STUDY —
“”Our RRs for comparing the face mask and hand hygiene group to the control group suggest an overall reduction in the primary incidence of influenza. However, we only analyzed 34 incident cases of influenza during the study and this limited our statistical power. Nonetheless, the RR for the layered intervention group was of even greater magnitude and in the same direction as the cumulative RR for ILI. These trends suggest that face masks and hand hygiene should be encouraged during seasonal influenza outbreaks and especially during the beginning of a pandemic when vaccines may not yet be available.””
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0029744