Trial of hundreds of thousands in Bangladesh finds masking 'modestly' decreased COVID infections

 A mask promotion campaign in villages in Bangladesh modestly reduced COVID-19 infections, according to a massive new study that is the first of its kind.

Conducted by researchers from Yale University, Stanford University, the University of California, Berkeley, and nonprofit organization Innovations for Poverty Action, the study employed a randomized controlled trial considered the gold standard in medical research.

"Community-wide masking can be an extremely effective tool to combat COVID," tweeted Jason Abaluck, a Yale professor of economics who co-authored the study.

The researchers randomly assigned 600 villages in Bangladesh to two groups, with households in half of the villages receiving free masks, as well as education and training on proper mask use. The other half of the villages, the control group, did not receive any mask education. Researchers monitored the villages for mask use in the following weeks.

The study found that the rate of mask-wearing was about 42% in the treatment villages, but only 13% in the control villages.

Over 335,000 participants in the villages filled out surveys asking if they experienced any COVID-19-like symptoms, and over 27,000 said they had. About 40% of those who said they had symptoms consented to blood tests.

The blood tests revealed that 0.76% of villagers in the control group tested positive for COVID-19 versus 0.69% in the treatment villages, a reduction of 9%.

The “intervention demonstrates a scalable and effective method to promote mask adoption and reduce symptomatic SARS-CoV-2 infections,” the researchers concluded.

The study also examined surgical masks versus cloth ones. There was no difference in infections among villages that used cloth masks versus control villages, but there was an 11% drop in infections among villages that used surgical masks.

The study has several limitations. Because researchers did not take blood samples from those who did not report symptoms, the study was unable to determine if mild or asymptomatic infections were higher among villages with lower rates of mask use. Nor could the study rule out the possibility that those who consented to blood tests were in some important way different between the treatment and control groups, thereby biasing the results.

https://news.yahoo.com/randomized-trial-hundreds-thousands-bangladesh-162300590.html