Out today extensive systematic review on #facemasks that I led for @royalsociety @BritishAcademy_ going beyond medical but also including behavioural & policy literature – thread of the main findings….
royalsociety.org/-/media/policy…
royalsociety.org/-/media/policy…
Many countries (~70) recommended #facemasks already in mid-March immediately after WHO announced #COVID19 pandemic with over 120 requiring them, mostly everywhere. Asian countries with previous SARS experience had early and universal usage 
Our meta-analysis shows that cloth face coverings are protective for the wearer in healthcare settings with a 54% lower relative odds of infection compared to no #facemasks royalsociety.org/-/media/policy…
The type of #facemasks fabric is vital with high grade, cotton, hybrid material and multilayer masks the best – and you need to fit them correctly #facemasks can be made at home or purchased
Key behavioural factors underlie public #facemasks compliance: (1) understanding how virus works, (2) risk perception, (3) socio-political systems, experience with pandemics, trust , (4) individual characteristics, (5) perceived barriers (shortage, comfort)
