3 thoughts on “Heterogeneity, And Covid”

  1. From one of the links:

    In fact, the findings suggest that people with blood type A face a 50 percent greater risk of needing oxygen support or a ventilator should they become infected with the novel coronavirus. In contrast, people with blood type O appear to have about a 50 percent reduced risk of severe COVID-19.

    Just called my primary care office to see if I could confirm mine (pretty sure it’s O+). She said she wasn’t seeing anything and that most normal blood work (cholesterol, etc.) doesn’t even include that, which kind of blew me away somewhat.
    Looked up the prevalence of types and among caucasians it’s not as different as I thought: 37% O+, 33% A+.
    For all you A’s out there: stay safe.

  2. For simplicity, let’s stipulate that the preponderance of people are either type A or type O.

    Your risk with type A is RA and your risk with type O is RO. If people with type A face a 50 percent greater risk, greater risk than who? Greater risk than those with type O, meaning

    RA = 1.5*RO,

    Hence, the risk for RO is reduced, again reduced relative to who else but the type A people? From the above equation

    RO = RA/1.5 = .667*RA = (1 – .333)*RA

    meaning the risk reduction for having type O is only 33.3 percent?

    Think of a car analogy. I could buy a new Camry that gets 50% better MPGs than my 1997 Camry, which would allow me to travel 15,000 miles in the new Camry for the same gas expense as 10,000 miles in what I am driving now.

    Now suppose I limit my driving to 10,000 miles/year, the old Camry get 25 MPG on average and a new one gets 37.5. The old Camry uses 400 gallons of gas, which at $2.50/gallon here in the Midwest (sorry, Rand) works out to $1000. The new Camry uses 266.7 gallons or $667, a savings of $333 or about 33 percent.

    Because MPG ratings inflate the perception of the savings, our European cousins require gas mileage to be reported in liters/100 km, which relates directly to the savings from driving a car with a lower-is-better liter/100 km rating the same yearly amount.

  3. Right now there is no rational reason for an individual to get tested. Here (Texas) it takes between one to two weeks to get results with the shorter time for those willing to pay for rush. What you should be doing is trying to rest and get well, not driving around for days, sick and short of breath, trying to get a test that will have no bearing on your condition or treatment like one person I read about. By the time he gets results it will most likely be over one way or another.

    Pooling just delays actual, individually useful results even further. Most places have probably exceeded the threshold of prevalence or will soon anyway.

    The large proportion of positive results in people without symptoms makes me and at least one person untitled to an opinion suspect a large false positive rate.
    https://archive.is/8rLzi#selection-203.0-203.35

    What he suggests would not be correctable by retesting since it’s is a systematic weakness in the test.

Comments are closed.