Yesterday, Germany’s Health Minister Karl Lauterbach tweeted a link to one of the most transparently idiotic pre-prints on masks that has ever been produced. In fact, the “study” is so bad, I want to assume that it is bait to humiliate whoever shares it. Otherwise, I wonder if the one professor listed in the six study authors approved this being posted to medrxiv… at least with his name attached.
Here is what Minister Lauterbach had to say about the study:
“For everyone who is still unsure whether masks protect against COVID: here is a new American mega study that evaluates over 1,700 studies. The benefit of the masks is very large, undisputed and applies to many areas”
The study claims to be a systematic review of the literature. Here is a brief description from the abstract:
The initial review yielded 1732 studies, which were reviewed by three study team members. Sixty-one full text studies were found to meet entry criteria, and 13 studies yielded data that was used in the final analysis. In all, 243 subjects were infected with COVID-19, of whom 97 had been wearing masks and 146 had not. The probability of getting COVID-19 for mask wearers was 7% (97/1463, p=0.002), for non-mask wearers, probability was 52% (158/303, p=0.94).
If Lauterbach made it this far, then he had no business sharing this study under the old adage that things that look too good to be true, probably are not. Such a discrepency in the differences between mask wearers and non-mask wearers should be a sign that something is wrong.
No. Stop. Rewind.
The study claims to be a review of the literature. Why are they adding subjects together from different studies with different methodologies? This should never be done. Ever. Just from a cursory glance at the abstract, before the authors ever explain their methodology (note, they never do), the results are absolutely ludicrous.
Of the 1732 records the authors reviewed, only 61 met “entry criteria” into the review. Note, the entry criteria is never actually mentioned in the paper. Of those, 48 of those were excluded… “with reasons” (reasons not specified).
In the end, only 13 studies made it into the paper. These studies were almost entirely from the early stages of the pandemic — January to August 2020. Except the one outlier… that was from 2004.
The studies seem to be chosen at random and completely disconnected from any potential entry criteria that is found in a traditional literature review.
One study that the authors included to show masks are effective was concerned with evaluating whether people were wearing masks properly in a Chinese hospital from January 27th to January 29th 2020.
Another study was just a handful of arbitrarily selected cases in South Korea at the beginning of the pandemic with absolutely no statistical analysis done.
My personal favorite “study” was the one-pager that explained how to French Army performed 20 tracheotomies while using military issue gas masks, which the authors considered +20 cases of masks being effective in the prevention of viral transmission… (the entire paper is shown in the screenshot below!)
Most of the cases in this “systematic review” came from a Chinese study that surveyed families with and without secondary transmission. Of course, most of the families with secondary transmission disinfected their house less, had worse ventilation, larger families, smaller living quarters, and different infection characteristics.
Honestly, I won’t beat a dead horse and go through the rest. This “systematic review” is garbage and Germany’s Health Minister should resign in disgrace for sharing it.
13 studies kept out of 2730, 0.47%
That is slightly higher % compared to the covid death rate on the Diamond Princess, 9 out of 3711, 0.24%.
Both numbers are so ridiculously small, that any conclusions drawn from either event that attempts to change the entire world should be rejected.
I agree Germany’s Health Minister/propagandist Karl Lauterbach should resign, but for a many more reasons than just sharing this study!