I'm not going (yet), and will stick around. I just think we've exhausted the mask science to the point where no-one has a 'killer' argument, nor can they cite a conclusive study.
Sure - and, I've said, I'm all-but-certain that the reason why no-one can cite a 'conclusive study' doesn't exist and, as I recently suggested, which, in practical terms, may well never be able to exist - not because the trial 'may not be conclusive' but, rather, because a trial looking for the sort of effect I envisage as possible (in relation to 'the protection of others') may well be essentially impossible to conduct (see below).
It reminds me of arguing whether God exists or not. Impossible to disprove, and rather hard to provide anything conclusive in His favour!
Indeed. The former would obviously be even more difficult - since 'proving negatives' is not really directly possible.
The conclusions we draw from this largely seem to depend on our prior dispositions, ranging from 'probably no effect' to 'possibly some effect, but we don't know.' Both are reasonable positions.
Sure, but those 'prior dispositions' do not have to be without a basis. In some senses, I think it's a matter of degree, since I would dare to suggest that it is essentially 'impossible' that masks do not provide
any protection (protection of others from an infected person), even if the protection is very small. Some droplets exhaled by an infected person will contain some virus particles, and a face covering of any sort will intercept some droplets - so it seems inevitable that there will be 'some' (even if only a tiny amount) of protection against viruses infecting others.
My focus has been to demonstrate that the evidence is weak, whether such weak evidence should be sufficient to mandate masks (on threat of criminal prosecution) ...
Yes, I understand that, and have some sympathy with that view, but the problem is that I think this is a 'fairly unique' (if such a concept ius possible!) situation. As we have agreed, one would really like something regarded as 'conclusive evidence' before mandating anything. However if, as I have suggested, it is next-to-impossible to undertake a trial which could provide 'conclusive evidence' (in one direction or the other), it would seem a pity to use that lack of evidence, alone, as a reason for not 'mandating' something that might perhaps be significantly beneficial to the population.
As I said, this is a 'fairly unique' situation. In my time, I have designed plenty of difficult and complex RCTs, but I'd probably walk away from this one. The medical and statistical design of a 'satisfactory study' would be straightforward enough (albeit probably very large and costly, in all senses) but, at least to my mind, the logistical, practical, ethical (and probably 'legal') hurdles would almost certainly be insuperable ...
In terms of investigating the ability of masks to reduce transmission to others, the only relevant data would come from people with known active (symptomatic or asymptomatic) Covid infection, and they would presumably have to be 'selected' as such, since one would otherwise probably have to recruit a vast number of subjects (probably at least hundreds of thousands') and test them very frequently, in order to get the required number of subjects with active infection to study. One would then have to actively encourage the subjects with 'known active Covid infection' (both the 'masks' and 'non-mask' groups) to 'mix freely' with the general population (assuming they were well enough so to do!) in all environments - presenting the ethical, and quite probably legal, impediments. Finally, one would have to somehow identify and follow up all of the contacts of the infected subjects during their period of ('freely mixing') infectivity - which would, again, probably be next-to impossible.
Although I/we have tried hard, neither I nor my colleagues can really think of any particularly satisfactory 'other way' in which such a study could be undertaken. In terms of a traditional RCT, the ethical/legal problems are probably insuperable - the only relevant data is that which would come from people with known active infection who were asked to 'freely mix with the population', yet people are (very reasonably) expected to isolate themselves (not 'freely mix with the population'!) as soon as they become 'known to have active infection'!
If one moves away from an RCT, one could try to undertake a 'bottom line' (essentially 'epidemiological') study, by simply looking at the infection rates in two very large populations (e.g. two whole cities), in one of which everyone was 'encouraged' to wear masks and in the other where everyone was encourage to not wear masks. However, there are so many other confounding factors that could result in a difference in infection rates between two cities/whatever that it would be essentially impossible to determine whether any apparent difference was due to mask wearing (or not) or something else. It has been suggested that it might be a little easier in large, captive, fairly controlled and 'complaint' environments such as the armed services, but even that would be far from satisfactory.
Hence, although it's something that I have very rarely have had to say in any other situation, I think the hypothesis of interest (to me!) in relation to masks is probably, in practical terms, essentially 'untestable' - unless, that is, you have some suggestion as toi how it might be done?!
... whilst pointing out that masks are far more "useful" as a behavioural tool dressed up as a medical one.
As I've said, I don't personally see that as something without benefit, regardless of clinical efficacy (or its absence).
This has been a very interesting thread so far, and I thank
@JohnW2 for starting it.
You're welcome. The whole subject has become a very significant 'part of my life', so it was perhaps inevitable that I would start it sooner or later (and the government have somewhat dictated my timing!) - albeit in a totally inappropriate forum (the PTB seem to have tolerated it so far!).
Perhaps we can next explore the evidence for efficacy of the more severe lockdown policies (which was probably the original intention)?
It was indeed - since I think we are all agreed that, even if masks have some efficacy, it's presumably a relatively small part of the whole 'package' ('the package that was'
).
I certainly don't think that this should in any way be a party-political issue, but I have to agree with Keir Starmer's view that to switch off virtually all formal restrictions simultaneously 'in one fell swoop' in six days time is (to be a little less emotive than him!) 'less than prudent'. The thing I found most extraordinary about today's Press Conference is that the PM and his advisors repeatedly stressed that we have to 'move forward very slowly and cautiously", but in the same breath as the PM was announcing that virtually all of the formal restrictions are very soon to be switched off simultaneously! I can but assume that the government is simply 'passing the buck', hoping that the people will do what government probably should be doing (gradually, not suddenly/totally, relaxing the restrictions), but doing it in a way that will enable them to blame someone other than themselves if/when things 'go wrong'!
Kind Regards, John
