[Goose]

Point estimate is that it reduces chances of infection by 15% (on a relative basis), but as I mentioned, the results are broadly compatible with a reduction of almost 50% all the way to no effect whatsoever (or even a small increase in risk).

BC

Even 15% is better than nothing. Granted, since the study is under powered it cannot determine the effect with great precision. I think we are all still examining the effect of masking in reducing the spread of COVID-19 in both directions. Obviously, it has been tricky to get data and the data that we do get has to be peeled apart from other effects. It would seem probable, given the studies we actually have seen, that the effects of masking are non-trivial but not overwhelming, in the 25% range maybe. That level of effectiveness is obtained with essentially no downside, and is therefore very worth having.

One factor that makes the evaluation of masking difficult is that it is often coupled with social distancing. Clearly, in the case of health care professionals, there is reason to believe masking is protective and quite effective (and data to show this as I understand it). It is probable that masking is much less important when there is significant social distancing going on and close contact is infrequent. It makes doing studies lots harder.

[Goose]

Point estimate is that it reduces chances of infection by 15% (on a relative basis), but as I mentioned, the results are broadly compatible with a reduction of almost 50% all the way to no effect whatsoever (or even a small increase in risk).

BC

Even 15% is better than nothing. Granted, since the study is under powered it cannot determine the effect with great precision. I think we are all still examining the effect of masking in reducing the spread of COVID-19 in both directions. Obviously, it has been tricky to get data and the data that we do get has to be peeled apart from other effects. It would seem probable, given the studies we actually have seen, that the effects of masking are non-trivial but not overwhelming, in the 25% range maybe. That level of effectiveness is obtained with essentially no downside, and is therefore very worth having.

One factor that makes the evaluation of masking difficult is that it is often coupled with social distancing. Clearly, in the case of health care professionals, there is reason to believe masking is protective and quite effective (and data to show this as I understand it). It is probable that masking is much less important when there is significant social distancing going on and close contact is infrequent. It makes doing studies lots harder.