Clearly, physicians here failed to calculate an exact positive predictive value in the example. The question is does that inability affect their 1) medical care delivered and 2) communication with the patient and the patient's own informed decision-making.
In speaking to 1-- there are many examples to choose from from probably any medical specialty but let's stick to breast cancer screening since that's the example from the article. USPSTF presents their recommendations[1]. I'd encourage anyone with interest to at least skim the rationale presented on the page below those recommendations. They very well consider prevalence as well as efficacy of specific tests given the presence of different risk factors in a patient (age, family history, etc). Importantly, those and many other screening guidelines are applied by primary care physicians who may not otherwise be able to calculate exacting probabilities.
[1] https://www.uspreventiveservicestaskforce.org/Page/Document/...
In speaking to 2-- patient autonomy of course requires an appropriate understanding of the tests they receive, any risk to those tests and the benefits and harms of true positives, false negatives, etc. The associated frequencies, albeit with some degree of imprecision are avaialble by reference and I'd suspect they're memorized by most radiologists reading mammograms and the breast surgeons involved in tested positives-- even if they may not be able to calculate them. If the doctor doesn't have them memorized-- they should be available by referencing the relevant guideline.
College: RPI. Graduation year: '91.
This book is a good introduction, includes a lot of anecdote from different health care professionals across a range of different testing (including cancer and HIV), and mentions the research across different health care professionals.
https://www.amazon.com/Reckoning-Risk-Learning-Live-Uncertai...
Here's an extract: https://imgur.com/zO4zkl4
P.S. I'd love to have someone animate this in Javascript!
There is a limited demo there as well.
There's even a book & several articles out there arguing that getting tested for cancer might be a bad idea: https://www.theatlantic.com/health/archive/2015/06/should-I-...
I met a young man (early 20's) who'd recently arrived in town for the purposes of "recovery". Having learned something about people's problems with self-medicating I asked, "People usually know when their problems with substances started. When did it start for you?"
He instantly said that when he was in third grade his teacher thought he was disruptive. Parents took him to the doctor, who prescribed medication. When he got to 9th grade he gave his parents an ultimatum: "if you don't take me off these drugs, I'm going to kill myself." His parents promptly took him off the drugs that didn't address the boredom he'd experienced in his suffocating 3rd grade classroom, and that's when he started self-medicating with whatever he could get his hands on.
The DSM is the mental health industry's guide to help practitioners precisely diagnose symptoms. The problem is the industry frequently jumps to treatment without concern as to the cause of the patients' symptoms.
Court-ordered treatment (aka "assisted outpatient treatment") is where the mental health industry decides to force a patient to take the drugs they think they need. I have the affidavits that were filed against my friend. They say, essentially, "Patient expects us to believe that her symptoms are related to consuming 2 bottles of liquor a day. She is clearly in need of court-ordered treatment because she does not believe that she has a chronic condition. We know that she has a chronic condition because she's had two previous orders for treatment. She took herself off our forced services 4 years ago, and here she is again."
Before this went down, I'd decided that my friend's substance abuse problems were related to her having been adopted, exposed to meth amphetamine as a pre-teen, having "lost her future" at 16 years old when she was expelled for self-medicating with what is now approved as a breakthrough therapy for PTSD (MDMA), and having been injected with a prescription endocrine disruptor [0] with the black-box warning of "cortisol deficiency" at 18 or 19 years old. This "birth control" drug is known to make some women suicidally-depressed. Cortisol deficiency is now associated with psychosis. My friend allowed that maybe the injections took her from "drug abuser" to "drug addict".
[0] https://en.wikipedia.org/wiki/Depo-Provera
In the world where mental health professionals address causes rather than symptoms and treat conservatively when the causes of a condition are unknown, those doctors would have recognized my friend's presentation as a form of substance-induced psychosis [1], and provided support to help her sober up.
[1] https://en.wikipedia.org/wiki/Substance-induced_psychosis
Rather than provide rational treatment, they just force her to take "anti-psychotics" in the delusional belief that their drugs (rather than sobriety) are what allows my friend to be functional. At one point they thought she needed two different drugs. My friend explained her presentation as, "I'm sorry, these drugs make us slow".
Every medical specialty has practices that aren't actually justified by the findings of science. I believe Psychiatry is the most important of the medical specialties, but the path "mainstream" practitioners has taken since the 1950's has been a mistake: most psychiatric drugs are just modern FDA-approved "patent medicines" [2] that don't actually address the causes of the patient's symptoms. While some people like their psych drugs, they'd probably do much better with more scientific approach to their complaints.
My best friend's father is a paranoid schizophrenic. Antipsychotic medication allows him to live a relatively normal life.
How do you know that it's the medication that allows him to "live a relatively normal life", and not the other factors?
If you want to trade anecdotes... My other friend's father fell out of a tree and broke his back when she was a child (iirc). Some time later they decided he was a "schizophrenic". He's been on antipsychotics ever since. His condition has spiraled downward over the subsequent years. Last I heard he was full-on crazy. If the doctors had provided supportive treatment instead of suppressive, his life trajectory would have been totally different.
My aunt's good friend had a "psychotic break" soon after her husband died unexpectedly. The friend was put on "anti-psychotics". She's now dying of liver failure, certainly as a consequence of her long-term drugging.
The ugly truth about so-called "antipsychotic medication" is that the class is palliative rather than curative, and actually causes the deterioration it supposedly treats.
Robert Whitaker makes the case that medications turns people's "episodes" into chronic conditions: https://www.madinamerica.com/2016/07/the-case-against-antips... and https://www.madinamerica.com/2018/03/a-tale-of-two-studies/ and https://www.madinamerica.com/2017/09/thou-shall-not-criticiz... , for example.
