Sensitivity

Sensitivity

Medicine is the science of uncertainty and the art of probability.

—Sir William Osler

By Dr. Jim Ferguson

I got “carded” last week at Chick-fil-A. You may find this hard to believe because they don’t serve adult beverages. My wife, Becky, and I are great fans of this restaurant chain and especially their spicy chicken deluxe sandwich with pepper jack cheese. I believe if Chick-fil-A were in charge of our government everything would run efficiently and we might approach the liberal Democrat progressive’s notion of utopia. Did you know that 16th century Thomas More coined the word as the title of his book? Utopia derives from Greek of which means not, and topos which means a place. So, utopia is literally nowhere.

As the attendant took my order I asked for the free “Senior soft drink” as the frugal Becky advised. The young man looked at me and the absence of gray hair on my noggin. He then politely asked my age. I told him I was seventy and acknowledged I didn’t have gray hair to speak of. However, when I turned my head to show him the back of my balding head, I got my free senior drink to complement my spicy deluxe sandwich. And as always, it was sublime!

Becky and I are reading a book called Alienated America by Timothy P. Carney. It is a thoroughly researched work with excellent prose, but challenging complexity. The essence of the book is the absence of a faith perspective in our increasing secular culture. It reminds me of a book I read many years ago by Pat Buchanan called The Death of the West which was about population demographics. Neither of these works are beach books, but are worth reading if you want to understand what’s happening.

One of my axioms (Fergisms) is, “If you want to know about a writer, read his prose,” instead of Wikipedia. The essence of a writer is in his writing, and “is as palpable as a swollen knee” (another Fergism). Stephen King is a beautiful writer, but in my professional opinion, the horrors he conjures up reflect the mind of a disturbed person.

We hear a lot these days about sensitivity. It seems like so many have such fragile personalities and are so easily offended. I wonder if Minority Leader Kevin McCarthy was offended when Nancy Pelosi called him a moron last week? I wonder if the derogatory rhetoric came from the Speaker of the House or perhaps from the lips of a harpy? Pelosi is a woman – I think – so she can say anything because as a woman she’s another purported victim of white male supremacy.

Actually, this week’s essay is not about a lack of virtue or snowflake sensitivities, but about scientific testing. In our technologically driven modern world, testing is commonplace. Whether it’s a cholesterol level or a Covid swab of your nose, you’d like to know that the results are accurate, in other words, correctly negative or positive.

In the doctor world the validity of a diagnostic test is evaluated by considering the sensitivity and specificity of the testing methodology and results. Tests may be designed with a high sensitivity to avoid missing something. An analogy might be a commercial fishing net that pulls in everything. However, a test with a high specificity will avoid incorrect results. Using the fishing analogy, my grandson Oakley uses a specific lure for certain types of fish.

Interestingly, as sensitivity increases, specificity declines, and vice versa. In other words, making a test sensitive will increase the number of false positive results. Making a test very specific will lead to missing some issues.

Let’s consider Covid testing with nasal swabs. First, a sample of secretions/cells must be obtained from a person’s nasopharynx with the proper swab. Then the material must be carefully preserved and taken to a lab for analysis. Much can go wrong in the sampling and chain of custody procedure.

In the lab the sample is then placed on a testing strip which contains a specific antibody to Covid protein. If the protein of Covid is present, the antibody will bind to it and a linked colorimetric reaction will occur which can be detected. We take for granted the sophistication of such technology which is also utilized in a urine pregnancy test. If the test sensitivity is high, Covid will less likely be missed, but false positives are inevitable. If the specificity is high some Covid viral particles may be missed due to a minimum level of detectability by a test, but a positive result is reliable.

The doctor and skeptic in me considers such things. I wonder why there was virtually no influenza last year, while in a typical influenza season there would be 30 to 40,000 deaths in America. I guess Covid cured influenza.

The PCR (polymerase chain reaction) testing for Covid has been the gold standard because it is a very sensitive test. A patient sample is first treated with growth enhancing technology to multiply any Covid viral particles present. Then the colorimetric strip technology is utilized. Some months ago, I wrote about the inoculum effect. In other words, how many Covid viral particles are necessary to produce disease? No one knows. Might it be possible for one Covid virus on a swab be stimulated to multiply in a lab PCR test and prevent someone from competing in the Olympics? Perhaps this is why the CDC is canceling real time PCR testing at the end of 2021. When magnified many times by PCR the coronavirus might be detectable, but would that miniscule amount define infection or produce disease?

Lately, I’ve been concerned about the specificity of my prayers. Of course, I pray for my wife and children and grandchildren and friends, but I’m more likely to pray for the country as a whole rather than the people who make up the country. I don’t beat myself up about my shortcomings because I’m sure the Lord cuts me a lot of slack. And perhaps I get style points for my corrective efforts.

The Myers-Briggs personality instrument is based on the notion that we all have differing gifts. Though I am naturally right-handed I can develop my left hand. And so, it is with my personality and prayer life. I can be a better person by developing less gifted areas and praying more specifically.

Lord knows this country and its people need help.

 

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