Thread by @josenalencar

Edmund has chest pain.

The doctor orders troponin, a cardiac test for detecting heart attacks, and it’s positive. Diagnosis: heart attack.

In reality, Edmund had a pulmonary embolism.

Doctors will never discover this error. Follow the thread to understand the “troponin trap”.

When I say “doctors will never discover”, I’m not talking about the treating doctors, but any doctor. The error is not just diagnostic, but COGNITIVE.

The root of the problem lies in a bias called the “incorporation bias”.

This bias exists when a test result names a disease.

Remember I said elevated troponin indicates a myocardial infarction (MI)? MI is defined by elevated troponin with compatible clinical signs.

Notice that troponin is both the test and the definition of the disease.

This situation is more a scientific error than a practical one. Academics shouldn’t accept that a disease’s definition depends so heavily on a single test result. But we accepted it and now face the consequences.

So, what now?

Due to incorporation bias, the diagnosis will always be “falsely” correct. If Edmund dies from the embolism, it’s deemed complications of a MI; if he survives with embolism sequelae, the embolism was not in the day of the “MI”.

Even if someone suspects that on the day of the “myocardial infarction” it was actually a PE (which also raises troponin), there’s no way to prove it retrospectively.

The diagnosis is set forever.

This leads to another bias.

We gain experience from successes and mistakes. But the mistake with Edmund will never be acknowledged. Thus, the hospital staff won’t review this case, regardless of Edmund’s fate: the diagnosis was “correct”.

Why debate?

Since we’re never wrong, we never get feedback on our errors. This is the “feedback sanction bias”.

Due to incorporation bias, we lose the chance to learn unless someone shakes us and says: my friend, beware of these biases! It’s a paradox!!

This shake is exactly what I did in my article published today in Acta Cardiologica, explaining these biases through a clinical case I call the “Troponin Trap”.

The first 50 clicks on this link can read for free:

tandfonline.com/eprint/FNBMNTK…

After 50 courtesy clicks, the article will be locked at this link:

url6649.tandfonline.com/ls/click?upn=u…

To reflect further, Edmund was part of a study in the hospital to determine the accuracy of a new troponin kit.

In the study, Edmund is a “true positive” for troponin detecting myocardial infarction. But in real life?

Attention: an experienced and non-overloaded team would obviously detect PE using the appropriate methods.

But this doesn’t rule out the existence of inexperienced or overloaded ER teams worldwide who may make this error.

The tweet and the article are not about you or me, nor about doctors and how they err, but about biases.

It’s about how the definition of myocardial infarction leads to cognitive hurdles and showing them could be just what a doctor needed to change their approach.