Not sure if anyone else noticed, but a preprint study that had claimed there is a 1 in 1,000 risk of myocarditis from vaccination has been retracted due to a rather extreme math error. It is rather shocking (at least to me) that such a simple error could appear in a preprint from what appears to be a legitimate source (The University of Ottawa Heart Institute).
Some antivaxxers and antivax-friendly news sources are apparently still running with the original (incorrect) study findings.
>>>The study had calculated an incidence rate of myocarditis in the Ottawa region post-vaccination by dividing the number of occurrences of the heart inflammation condition over a two-month period (June and July 2021) in Ottawa (32) by the total number of vaccinations in the area (reported as 32,379 in the pre-print).
The incidence rate of myocarditis, using these figures, equates to 10 for every 10,000 doses of the vaccine.
The pre-print paper had used an incorrect figure for the number of doses administered in Ottawa over that two-month period, however.
Between the week beginning May 30 and the week starting July 25, there had been 845,930 vaccines administered in the Ottawa region, according to data published by Ottawa Public Health, which is far greater than the figure used to calculate the incidence rate (32,379) (
here ).
The denominator (total vaccines administered over a two-month period in Ottawa) used to calculate the incidence rate of myocarditis in the pre-print study was approximately 25 times smaller than the correct figure.
The study was then withdrawn on September 24 and in a statement the researchers said: "Our reported incidence appeared vastly inflated by an incorrectly small denominator (ie number of doses administered over the time period of the study). We reviewed the data available at Open Ottawa and found that there had indeed been a major underestimation, with the actual number of administered doses being more than 800,000 (much higher than quoted in the paper)” (
archive.is/UCKQK ).
“In order to avoid misleading either colleagues or the general public and press, we the authors unanimously wish to withdraw this paper on the grounds of incorrect incidence data,” they added. . . .
In response to the retracted pre-print, a spokesperson for the Centers for Disease Prevention and Control (CDC) sent Reuters a study released on September 3 which monitored adverse events following mRNA vaccines between December 14, 2020, and June 26, 2021, with data from Vaccine Safety Datalink. (
here ).
“Analyses of all ages combined did not detect a significant association between myocarditis/pericarditis and mRNA vaccines,” the report noted, although adding that there was evidence of “an association between mRNA vaccines and myocarditis/pericarditis in younger individuals”.<<<
Correction Oct. 4: corrects spelling of denominator in paragraph 13, and in the same paragraph corrects “25 orders of magnitude off” to “25 times smaller”. Changes 'magnitude' to 'factor' in verdict.
www.reuters.com
