Why Do They Bother?

I often wonder about news agencies. They publish flashy headlines, but the details later in the stories turn out to be much less interesting or conclusive. Here is a recent example from CNN health: “People with blood type O may have lower risk of Covid-19 infection and severe illness, two new studies suggest.” (At least citing two studies is better than their frequent practice of citing one unnamed source in their political news, but let's get into it.) 

 

The studies concluded, “People with blood type O may be less vulnerable to Covid-19 and have a reduced likelihood of getting severely ill.” To compound the weakness of this conclusion that they “may be less vulnerable” they add a disclaimer that “Experts say more research is needed.”

 

What we know so far, provided we read the headline carefully, is that something “may be” going on, and even if true, the connection is not clear.

 

A study from Denmark found that of a sample of 7,422 people who tested positive, 38.4% were blood type O, whereas 41.7% of a separate non-tested group of the 2.2 million Danish people has that blood type. The article doesn’t explain where that 2.2 million came from. The population of Denmark is about 5.8 million. Were those 2.2 million representative of the entire population?

 

It is likely the results were statistically significant or they would not have been published. Still, statistical significance is overrated, and the difference between 41.7% and 38.4% does not seem to be of any practical significance to a CNN audience. 

 

The difference for Danes with type A blood goes in the opposite direction, 44.4% ill compared to 42.4% of the population. But the Type O and Type A does not account for everyone, only 84.1%. The remaining type B and AB people must comprise 15.9% of the population and account for 17.2% of the cases, which is actually proportionally higher than the type A cases. Why they reported what they did, the way they did, is puzzling.

 

The second, a Canadian study, looked at a much smaller sample, only 95 critically ill patients. Of them, 84% of those with blood type A or AB required ventilators compared to 61% of type O or B. They didn’t make the same comparisons under the same conditions as the Danish study. The only common finding was the better performance of blood type O.

 

The final conclusion of the CNN article is that no one should worry and no one should become complacent. Blood type does not supersede other risk factors. The information is useful only to researchers in this narrow field of trying to discover a link between blood type and COVID susceptibility or seriousness. They “don't yet know what mechanism could explain the link” or if a link exists.

 

The fact that they were published in a journal called Blood Advances reinforces how narrow the focus for the studies was. It wasn’t really intended for the general public. Which brings me back to my original question. Why do they bother? 

 

Not to pick on CNN. The same useless information appeared in Forbes, NBC, UPI Health News, Science Focus and others. The pressure to fill airtime and Internet space must be overwhelming. We get such news with its exciting headlines whether it adds any value to our daily lives or not.