A large-scale study in Bangladesh has shown that periodic monitoring leads to tripling of mask wearing among people and substantial reduction in the spread of COVID 19 virus. The tripling of mask usage was sustained over the entire period of surveillance including a period after intervention activities ended.
The study found that periodic monitoring by mask promoters to remind people in streets and public places to put on masks is the most effective way to promote the practice. Alternatively, free mask distribution and role modeling by community leaders produced only small increases in mask usage during the pilot intervention.
The study conducted among more than 3.41 lakh adults in 600 villages of Bangladesh showed that text messages, public signage commitments, monetary or non-monetary incentives or village police accompanying the mask promoters had no significant impact on mask usage among the people.
The study concluded that free mask distribution alone was not sufficient to increase mass usage. Adding periodic monitoring in public places had large effects on their behaviour. It also found that rather than the threat of legal sanction, shame and people’s aversion to light informal social sanction had the greatest impact on promoting mask usage.
Another important finding of the study says that surgical masks with substantially higher filtration efficiency can be a cost effective alternative to cloth masks. It also found that aesthetic design choices and colors can influence mask-wearing.
The cluster randomised trial of community level mask promotion in rural Bangladesh was conducted by the National Bureau of Economic Research (NBER), Massachusetts, Cambridge. Public health experts from the University of Yale, Stanford University, John Hopkins Bloomberg School of Public Health, North South University of Bangladesh and a few others conducted the research as part of larger study evaluating the effect of mask wearing on transmission of SARS-CoV-2. The Study was conducted between November 2020 to April 2021.