Surgical masks don’t work either?
Honestly, I find myself again surprised with the conclusion on masks. I have not read the papers behind it because I’m sick of the stupidity of the discussion, as nobody except a couple of us are willing to change their minds in the face of NEW data. For instance IF Joshua or Frank, were to find an actual paper that creates some doubt. Good luck with that boys as it would be 80 no’s to 1 regarding efficacy, meaning the paper would be immediately questionable because the other 80 science teams had to screw up.
Again I find that my own assumptions about masks being effective during surgery might also be wrong. Common sense dictates; a mask (spittle blocker) over an open surgical wound must help prevent infection of the wound. It literally has to – how could that not be true?!!!
The signal (reduced infections) should be blatantly obvious. Common sense says it has to be, but like the complete lack of efficacy regarding viral spread of covid, according to measured data –maybe this surgical mask failure is also true. Crazy world. Each time an engineer tries something they know will work, and it doesn’t, the god of physics gives immediate feedback. I have some personal stories of being wrong on high performance two stroke motors, ultrasonic welding, optics, electronics etc.. In some of these other sciences like medicine, the long time frame and statistical nature of the feedback prevent ‘thought correction’.
Now this post was done in November 21 so this is not new for Bacon Time, but it is new for me.
Like myself and most other science minded folks, even the authors are incredulous.
Use of Surgical Masks in the Operating Room: A Review of the Clinical Effectiveness and Guidelines
KEY FINDINGS
The use of surgical face masks by staff in the operating room is presumed to reduce the frequency of surgical site infections. The evidence identified and included in this report finds no evidence basis for this presumption. The consensus of the systematic reviews included in this report is that there is a paucity of data on this topic, and that current evidence is lacking for altering clinical practice. The included guidelines of this report are also in agreement that the long standing practice of wearing surgical face masks in the operating room should continue despite the lack of clinical efficacy evidence.
I don’t know guys, I’ve not done my homework on surgeries but this feels the same as the last time I was wrong about masks.
the Air Vent 
Not sure if wearing an N-95 mask will be effective at reducing viral or bacterial loads into my lungs in a few minutes, but I can confirm that the device has done a great job of keeping coal dust/ash out of my nose and lungs when I tend the Heitzer.
About a year ago we were surprised to learn that the “wood furnace/stove” in the basement was actually a 1981 model designed for use with coal. Luckily for us we were able to get some training in the proper operation of the device. Do wish the shaking and ash removal process(s) were a bit cleaner, but one has to work with what one has. I change out masks after a week or so of use as they get clogged after a while.
Cloth/paper masks do a pretty good job on big, chunky bits.
I still have half a dozen n95 masks in the basement that I got from WallMart. They were giving the things away last year.
I need to find a better way to empty the ash tray. Lots of small stuff floats just above the metal can when I dump the ash pan. Putting a piece of wax paper at the top of the ash pile in the can before I dump the pan helps to minimize floaters.
Unfortunately, every once in a while, my aim is a bit off and I have to use a wet cloth/paper towel to collect up the stuff once it settles. My less than stellar targeting is less of an issue this winter as I got a wider bucket.
A shop vav is out of the question?
Less than useless advice.
Cloth/paper masks generally don’t fit nearly as well as N95s. If you’ve ever worked in dusty environments (as I have) then you’d know that fit is a critical factor with regard to efficacy.
And besides, the “big chunky bits” are obviously less of a concern – health-wise.
I am just going to guess that the biggest reason for mask ineffectiveness in surgery is because surgery already is very, very, very clean.
I think the key point was that there is no evidence that the masks prevented infection. Absence of evidence is not evidence of absence. Frankly, Everything done in the surgery is to eliminate possible vectors of contamination of the wound. In order to show that masks work during surgery, surgeons would have to operate without masks. I doubt that would be allowed anywhere.
By the way, the purpose of the masks on the surgeons is not to keep the surgeon protected but to protect the patient’s wound from bacteria in the surgeon’s breath/spittle. There is a ton of evidence that there are bacteria in that stuff, so keeping it out of the wound makes a lot of sense.
Ssshh. Don’t stop the self parody.
bok bok bok
Null hypothesis is shown to be true. If you read the surgical article, operating without masks is exactly what they did.
> The hundreds of mask studies for viral spread used from hundreds to many hundreds of thousands of people. This IS evidence. This is not the case of an absence of evidence but rather absence of effect.
First, some studies HAVE shown an effect, albeit limited. So either your ekhjnf or you haven’t comprehensively surveyed the literature. In fact, inlknkw that you at least commented on the methodology of one of the studies and wrongly described the methodology and ignored relevant aspects of the study, merely sobyik could dismiss the limited effect it reported.
Second, the vast majority of the studies were conducted in an entirely different context.
Third, the evidence on the whole was insufficient as a foundations for drawing firm conclusions – exactly as you have done. You even ignored how the Cochrane Review characterized the evidence in your haste to say that it proved your firm conclusions.
You’re just wrong all the way down.
There’s an absence of quality evidence, upon which to draw firm conclusions, and there isn’t an absence of effect but there is an uncertain effect.
And btw, there are all minds of meta-surveys, of all different quality. As it happens the Cochrane Review is among the best, but even a good Cochrane Review can’t improve the quality of the evidence. Part of the reason why we can say that the Cochrane Review is of value is because it does a comprehensive job of characterizing the literature (which, of course, you ignored).
And no – if the evidence isn’t good enough to evaluate the null hypothesis then the null hypothesis hasn’t been “shown too be true.” Truly fascinating (although not surprising) you’re that confused.
So either you’re lying or you haven’t comprehensively surveyed the literature. In fact, we know that you at least commented on the methodology of one of the studies and wrongly described the methodology and ignored relevant aspects of the study,, merely so you could dismiss the limited effect it reported.
“some studies HAVE shown an effect”
Show me which ones Joshie. The only things with an “effect” have not used blind controls allowing all kinds of stupid to encroach. The ones with controls, – nothing.
zero
zip
zilch
nada
And plenty of quality evidence of it.
All you have to do is show me one where I’m wrong and you can be right!!!
As I said, you already commented (on two, actually) with inane reasoning that made no sense.
It’s your unfalsifiabile/no true Scotsman mindset: there “are no studies” because you reject any study that falsifies your certainty, with bogus logic.
And the only studies you don’t reject use methodology that’s inadequate to support firm conclusions – exactly as he Cochrane Review explained. Which is just hilarious because you then cited the Cochrane Review to support your firm conclusions.
You explicitly apply standards selectively so that you can believe you’re right when you’re obviously spouting nonsense.
You tie yourself into the cutest little logical knots.
Fun to watch.
But please be careful. You’re going to upset one of your 5 other commenters by responding to my comments.
I note that you have provided zero double blind studies which had a signal.
Odd.
Paul,
You deserve a better answer from me. The hundreds of mask studies for viral spread used from hundreds to many hundreds of thousands of people. This IS evidence. This is not the case of an absence of evidence but rather absence of effect. The decently built studies showing any reduction in viral spread failed universally. Not a single success.
Many of these mask viral-efficacy papers had the same style summaries as the surgical mask paper above. Complete scientific incredulity. They don’t want to believe their result because it isn’t what they expected. Frankly, I can’t blame them one bit. Would you want to be the ‘scientist’ putting that out?
In the surgery studies there were only thousands of patients. More patients were infected without masks than with. This doesn’t make sense to me or them. I would like to see a lot more work done on surgical masks in the operating room before I accepted this result. However, this IS also an evidence based result.
As a final statement, the last two posts I did on masks were meta-analyses, which are the WORST kind of paper. In the case of efficacy against viral spread, I have read many study papers. In the case of surgical infection, I’ve not properly read any. I really don’t have an opinion on the surgical masks other than that same sick feeling in my stomach I got when I found the viral spread studies not working.
Thanks for the more detailed response. If they had evidence, then good, I guess. That surgeons were operating without masks is amazing to me – I thought they were a group that was adverse to risking patients unnecessarily. I’d think that any patient that got an infection when a Dr. wasn’t wearing a mask during surgery would have grounds for a mal practice suit.
You said “More patients were infected without masks than with. This doesn’t make sense to me or them.” More patients being infected when masks were not being used would be what I would expect to see. Not sure why the result is a surprise.
As I noted, bacterial infections are what they are protecting against and those things are big enough for surgicl masks to block, unlike virus particles.
I agree that Meta Analyses are not very convincing since they tend to be “wee pee” exercises. That is, looking for correlations in the data that satisfy low chance criteria – 1 in 20. I worked as a safety guy in aerospace where we tried to design systems that had chance failures that were less probable than 1E-9 per flight hour. And we still had events occurring in the fleets! It makes me laugh that they think 1 in 20 is a low probability event.
You got me, I wrote it backwards. If you read the link in the article, bacontime has some detail.
Here is a quote: