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Tag: false positive

Who Is the Better Radiologist?

flying cadeuciiThere’s a lot of talk about quality metrics, pay for performance, value-based care and penalties for poor outcomes.

In this regard, it’s useful to ask a basic question. What is quality? Or an even simpler question, who is the better physician?

Let’s consider two fictional radiologists: Dr. Singh and Dr. Jha.

Dr. Singh is a fast reader. Her turn-around time for reports averages 15 minutes. Her reports are brief with a paucity of differential diagnoses. The language in her reports is decisive and her reports contain very few disclaimers. She has a high specificity meaning that when she flags pathology it is very likely to be present.

The problem is her sensitivity. She is known to miss subtle features of pathology.

There’s another problem. Sometimes when reading her reports one isn’t reassured that she has looked at every organ. For example, her report of a CAT scan of the abdomen once stated that “there is no appendicitis. Normal CT.” The referring physician called her wondering if she had looked at the pancreas, since he was really worried about pancreatitis not appendicitis. Dr. Singh had, but had not bothered to enlist all normal organs in the report.

Dr. Jha is not as fast a reader as Dr. Singh. His turn-around time for reports averages 45 minutes. His reports are long and verbose. He meticulously lists all organs. For example, when reporting a CAT of the abdomen of a male, he routinely mentions that “there is no gross abnormalities in the seminal vesicles and prostate,” regardless of whether pathology is suspected or absence of pathology in those organs is of clinical relevance.

He presents long list of possibilities, explaining why he thinks a diagnosis is or is not. He rarely comes down on a specific diagnosis.

Dr. Jha almost never misses pathology. He picks up tiny lung cancers, subtle thyroid cancers and tiny bleeds in the brain. He has a very high sensitivity. This means that when he calls a study normal, and he very rarely does, you can be certain that the study is normal.

The problem with Dr. Jha is specificity. He often raises false alarms such as “questionable pneumonia,” “possible early appendicitis” and “subtle high density in the brain, small punctate hemorrhage not entirely excluded.”

In fact, his colleagues have jokingly named a scan that he recommends as “The Jha Scan Redemption.” These almost always turn out to be normal.

Which radiologist is of higher quality, Dr. Singh or Dr. Jha?

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USPSTF – It’s About Time

The numbers are stark. According to the United States Preventive Services Task Force, for every man whose death from prostate cancer is prevented through PSA screening, 40 become impotent or suffer incontinence problems, two have heart attacks and one a blood clot. Then there’s the psychological harm of a “false positive” test result, which is 80 percent of all “positive” tests. They lead to unnecessary worry, follow-up biopsies, physical discomfort and even harm. Final grade: D.

Three men close to me have been diagnosed with prostate cancer late in life. Each was around 70. My dad, already in throes of advancing Alzheimer’s disease, did what the doctor ordered (actually, I suspect my mom told my dad to do what the doctor ordered). He had surgery. And for the last six years of his life, which until his final three months was at home, she cleaned up after him because of his incontinence. My neighbor made the same choice. He quietly admitted to me one day that he suffers from similar symptoms, but he is grateful because he believes his life was saved by the operation. And my friend Arnie? I’ve written about him in this space before. He was diagnosed at 70, and being a psychiatrist with a strong sense of his own sexual being, understood the potential tradeoffs. He decided to forgo treatment. He died a few years ago at 90. I never learned the cause.

So what does it mean that PSA testing gets a D rating?

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