1/9 This thread is a waste of time. It will change nobody’s mind. Nobody should really care what I think—I am no expert here. But, given the response on twitter about this excellent article, I felt like I needed to articulate my thoughts. nature.com/articles/d4158…
2/9 I have spent most of my career as an EBM proponent, hollering about the superiority of the RCT. Hell, @vinayprasad and I wrote a whole book about it. (No reason not to mix in a little shameless self-promotion). amazon.com/Ending-Medical…
3/9 However, people often forget that EBM is not blind adherence to an RCT; nor is it refusal to act without an RCT. Fundamentalism in all forms is bad. EBM requires integrating clinical experience and expertise with the best available evidence from systematic research.
4/9 So, masks. It's highly biologically plausible that they decrease transmission of COVID-19, especially if worn by both sides of an interaction. It is also wildly implausible that they cause harm--arguments about mask danger stand out even among the usual twitter kookiness.
5/9 As far as clinical experience, having worked almost every day since January in a busy hospital with mandatory universal masking I think I have experienced the success of this strategy.
6/9 As to the data, see the Nature article above. Data are far (very far) from perfect but combined with the two points above it seems unreasonable to think that harms of masks outweigh their benefits. (Yes, they are certainly not perfectly effective, nothing is).
7/9 With all due respect to the hardworking, dedicated researchers, RCTs of masks in less developed countries make me uncomfortable.
8/9 As to mandates, that is a political issue and I stay away from those (on twitter). I think people should wear masks (when they are at risk of getting infected or infecting others) because it is the right thing to do as we try to care for one another.
9/9 And, to end on a bright note and because XKCD is the best, a figure recommended by my daughter. xkcd.com/2367/
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1/6
A tweetorial in the guise of a story.
A woman is hoping to have her elderly mother visit from out of town. She and her husband are asymptomatic and have been very careful about contacts. The mother, who is driving from Maine, is well, and has had no risk contacts.
2/6
The husband suggests that he and his wife get tested to assure that it is safe for his mother-in-law to visit. Is he being thoughtful or is he trying to get out of having her visit?
3/6
It is hard to get good numbers for the test characteristics for NP, PCR test for COVID-19. But here are some numbers I have seen (bear with me, if you don't like the numbers, change them, doesn't much matter).
Sensitivity: 95%
Specificity: 85%
LR+: 6.33
LR-: 0.58
As my busiest month of EBM teaching winds down, thought it was a good time for a quick tweetorial of reading RCTs (without my usual pathetic B/W slides). These are the studies we, appropriately, rely on most in medicine but they can be misleading. What would you add?
How RCTS can be misleading #1
For studies with subjective endpoints, was the control really adequate.
A tweetorial.
One of my favorite points to making when teaching diagnostic reasoning it to stress that positive findings are immensely more important than negative ones. I believe this so strongly that it is point 4 on my diagnostic reasoning yellow card.
As an example, hearing an S3 is very powerful when it comes to diagnosing heart failure (LR+, 11) but the lack of tachycardia in a patient suspected of having a PE is meaningless when it comes to excluding PE (LR-,1.0).
Began this year’s “Critical Appraisal of the Landmark Medical Literature” course Friday with RCTs. These are the studies we, appropriately, rely on most in medicine. However, they can be misleading, thus, a Tweetorial (my first) of reminders with references. What would you add?
How RCTS can be misleading #1
For studies with subjective endpoints, was the control really adequate. amjmed.com/article/S0002-…