Peer Reviewed Study Questions Masks

( A previous study that claimed wearing a mask provides small but meaningful protection against COVID masks got a second look recently in a peer-reviewed “re-analysis” that was published in the Springer Nature journal Trials on September 15.

A team of statisticians, led by Ben Recht, a UC Berkeley machine-learning professor, reviewed the so-called Bangladesh mask study that appeared in “Science” in December 2021.

In the review, Recht expanded on his previous methodological criticisms of the Bangladesh study along with Carnegie Mellon mathematician Wesley Pedgen and University of Pittsburgh computational biologist Maria Chikina.

They argue that because studies like the Bangladesh study, led to “changes in social behaviors and government policies,” they must be “carefully vetted.”

The Bangladesh study, led by Yale economist Jason Abaluck, was based on cluster randomized control trials of 600 Bangladeshi villages.

According to Recht and his team, Abaluck’s study excluded crucial data, including the “raw numbers” from the trial that showed “the primary outcome [symptomatic seropositives] differed by a total of just 20 cases between the treatment and control arms” in a study population of 300,000.

The review notes that Abaluck’s team conceded the study had “substantial post-randomization ascertainment bias,” due to staff being aware “whether they were surveying a treatment or control village.” However, Recht writes, that bias doesn’t account for “the difference in size between treatment and control.”

Recht concludes that the data presented in the Bangladesh study “is consistent” with masks “having modest or no direct effect” on the instances of COVID in the study’s setting.

Read the full study HERE.