Dr Prasad, I have a Facebook friend who is a computer-science professor at the Sorbonne. (In the 1980s we met working as volunteers for the same NGO in Peshawar, training Afghan field medics during the Soviet occupation. We haven’t met in person since.) I’m 63, he’s in his late 50s. Last year he shared a link touting a study by some of his German colleagues from June 2020, *conclusively demonstrating* that mask mandates dramatically reduce the spread of COVID-19.
What the Germans did was to examine numbers of positive Covid tests, in the weeks immediately after the imposition of mask mandates at the peak of the spring 2020 wave.
Needless to say, if you ignore Farr’s law and impose a mask mandate at the peak of a wave, you’re going to get precisely the association you want, if you happen to want people to wear masks. The result would have been the same if the Germans had imposed a mood-ring mandate, or made everybody wear curly-toed Persian slippers.
I had a lot of fun with him. I pointed out that the Danes had already done an RCT weeks earlier showing a tiny, statistically insignificant benefit to mask wear - almost certainly confounded by mask wearers’ other well-known avoidance behaviors. But nobody would publish that study for months.
I suggested his German colleagues were party to a sinister, cynical (but at the same time rather feeble and desperate) plot by German health officials to discredit the Danish study before it found a publisher.
Oh, and throughout my reply I regularly referred to his colleagues as Krauts, just because I knew it would trigger the f*** out of him. (Did it ever, lol.)
He replied with some weak generalization about the purported limitations of RCTs, mostly to the effect that they’re difficult and costly ...
The episode illustrates your point about our ‘storytelling’ minds. Also, utterly brilliant people like my friend will believe transparently stupid stories, if that’s the narrative they prefer. Moreover, they’ll often seek to leverage government - ie ultimately, men with guns - to impose their stupid narrative on skeptics and dissidents. And they’ll call it The Science (TM).
The article fails to mention a key point. Namely, you only need an RCT when the effect you're looking at is rather small. As an example, consider multiple myeloma which I know VK treats a lot of. We know the course of the disease without treatment, and as far as I know spontaneous and complete remission in multiple myeloma is unheard of. Now lets say you had drug which, following a 1 week course, resulted in 100% full remission (i.e. no detectable evidence of any remaining malignant cells) and no relapse within a 5 year period in 100% of the patients treated with this wonder drug. (even 70-80%, of course, would be fantastic). Well you wouldn't need an RCT for this particular drug. Similarly, if there were a drug for stage 4 colon cancer which resulted in complete disappearance of primary and secondary tumors in 100% of the patients where it was tried. Well again, no need for an RCT. Where an RCT is absolutely critical is when the effect is far from obvious and the drug only works in a small number of cases or only prolongs life by a small amount.
Which brings one to the issues of masks and upper respiratory tract viral infections. The only reason to do an RCT is to show that masking has a small but significant effect. But even if the effect is statistically significant, if the effect is small (e.g. the 10% effect found in the Bangladesh trial if taken at face value), that's basically as good as zero in the real world. (i.e. who cares about a 10% reduction as it still means one will get Covid, just a couple of days later). and that's why every RCT done on masking and URIs prior to COVID was negative. So of course nobody wants to do a proper trial with Covid as that would be problematic for all the people involved in imposing draconian mask mandates.
Vinay, I continue to post the same thing here. Someday you may read these comments (although history says "no"). Some of the obvious (e.g., masking) trials could be done anytime and could have been started at any time over the past year when I posted a comment suggesting it. I expect that money could be found -- happy to work on that angle. And your endlessly long grant stack says you know how to do that in spades.
So why don't YOU do one or two of these RCTs in this area that is clearly so important to you (and the rest of us)? In fact, virtually all of the whiners about it just whine -- and complain that no one is doing an RCT. You would be first on my list to do one, but you are not.
Many, many years ago one of my whines was how many patients were dying that were on the cardiothoracic pump. I kept whining there were no studies and we had no idea why this was happening. Someone said "Well, if you are that concerned, why don't you do one?" I thought about it and they were right. So I did one which completely changed how anticoagulation has been done ever since in cardiothoracic surgery. The analog seems strong to me.
Not trying to strongarm you to doing something you do not like. But until you and your peers take this on, it remains an important question.
Well, this was *almost* an excellent rant. You seem (as you so often do) to have left out some important ancillary information that could only make your opinions stronger, not weaker. In the patois of the mythical George Babbitt, your post definitely had some "sizzle" yet was lacking in both "punch" and "pow". What are the *concealed assumptions involved* whenever any Cluster RCT is used? I think that you are dead right in arguing that Cluster RCTs could have, and should have, rapidly been crafted and performed very early in the COVID pandemic to generate more reliable bases for various public health and/or clinical policy adjustments, etc. But, with the usual due respect, I would opine that you are probably dead wrong to keep beating your Cluster RCT tom-tom over and over these days without evincing a wee bit more erudition, showing more attention to key details, and operating via the use of more authentic scholarship.
Dr Prasad, I have a Facebook friend who is a computer-science professor at the Sorbonne. (In the 1980s we met working as volunteers for the same NGO in Peshawar, training Afghan field medics during the Soviet occupation. We haven’t met in person since.) I’m 63, he’s in his late 50s. Last year he shared a link touting a study by some of his German colleagues from June 2020, *conclusively demonstrating* that mask mandates dramatically reduce the spread of COVID-19.
What the Germans did was to examine numbers of positive Covid tests, in the weeks immediately after the imposition of mask mandates at the peak of the spring 2020 wave.
Needless to say, if you ignore Farr’s law and impose a mask mandate at the peak of a wave, you’re going to get precisely the association you want, if you happen to want people to wear masks. The result would have been the same if the Germans had imposed a mood-ring mandate, or made everybody wear curly-toed Persian slippers.
I had a lot of fun with him. I pointed out that the Danes had already done an RCT weeks earlier showing a tiny, statistically insignificant benefit to mask wear - almost certainly confounded by mask wearers’ other well-known avoidance behaviors. But nobody would publish that study for months.
I suggested his German colleagues were party to a sinister, cynical (but at the same time rather feeble and desperate) plot by German health officials to discredit the Danish study before it found a publisher.
Oh, and throughout my reply I regularly referred to his colleagues as Krauts, just because I knew it would trigger the f*** out of him. (Did it ever, lol.)
He replied with some weak generalization about the purported limitations of RCTs, mostly to the effect that they’re difficult and costly ...
The episode illustrates your point about our ‘storytelling’ minds. Also, utterly brilliant people like my friend will believe transparently stupid stories, if that’s the narrative they prefer. Moreover, they’ll often seek to leverage government - ie ultimately, men with guns - to impose their stupid narrative on skeptics and dissidents. And they’ll call it The Science (TM).
China just completed the largest trial in history on lockdowns and masking.
The article fails to mention a key point. Namely, you only need an RCT when the effect you're looking at is rather small. As an example, consider multiple myeloma which I know VK treats a lot of. We know the course of the disease without treatment, and as far as I know spontaneous and complete remission in multiple myeloma is unheard of. Now lets say you had drug which, following a 1 week course, resulted in 100% full remission (i.e. no detectable evidence of any remaining malignant cells) and no relapse within a 5 year period in 100% of the patients treated with this wonder drug. (even 70-80%, of course, would be fantastic). Well you wouldn't need an RCT for this particular drug. Similarly, if there were a drug for stage 4 colon cancer which resulted in complete disappearance of primary and secondary tumors in 100% of the patients where it was tried. Well again, no need for an RCT. Where an RCT is absolutely critical is when the effect is far from obvious and the drug only works in a small number of cases or only prolongs life by a small amount.
Which brings one to the issues of masks and upper respiratory tract viral infections. The only reason to do an RCT is to show that masking has a small but significant effect. But even if the effect is statistically significant, if the effect is small (e.g. the 10% effect found in the Bangladesh trial if taken at face value), that's basically as good as zero in the real world. (i.e. who cares about a 10% reduction as it still means one will get Covid, just a couple of days later). and that's why every RCT done on masking and URIs prior to COVID was negative. So of course nobody wants to do a proper trial with Covid as that would be problematic for all the people involved in imposing draconian mask mandates.
Vinay, I continue to post the same thing here. Someday you may read these comments (although history says "no"). Some of the obvious (e.g., masking) trials could be done anytime and could have been started at any time over the past year when I posted a comment suggesting it. I expect that money could be found -- happy to work on that angle. And your endlessly long grant stack says you know how to do that in spades.
So why don't YOU do one or two of these RCTs in this area that is clearly so important to you (and the rest of us)? In fact, virtually all of the whiners about it just whine -- and complain that no one is doing an RCT. You would be first on my list to do one, but you are not.
Many, many years ago one of my whines was how many patients were dying that were on the cardiothoracic pump. I kept whining there were no studies and we had no idea why this was happening. Someone said "Well, if you are that concerned, why don't you do one?" I thought about it and they were right. So I did one which completely changed how anticoagulation has been done ever since in cardiothoracic surgery. The analog seems strong to me.
Not trying to strongarm you to doing something you do not like. But until you and your peers take this on, it remains an important question.
Read Judea Pearl on this
Well, this was *almost* an excellent rant. You seem (as you so often do) to have left out some important ancillary information that could only make your opinions stronger, not weaker. In the patois of the mythical George Babbitt, your post definitely had some "sizzle" yet was lacking in both "punch" and "pow". What are the *concealed assumptions involved* whenever any Cluster RCT is used? I think that you are dead right in arguing that Cluster RCTs could have, and should have, rapidly been crafted and performed very early in the COVID pandemic to generate more reliable bases for various public health and/or clinical policy adjustments, etc. But, with the usual due respect, I would opine that you are probably dead wrong to keep beating your Cluster RCT tom-tom over and over these days without evincing a wee bit more erudition, showing more attention to key details, and operating via the use of more authentic scholarship.