Folks across the country are paying hard cash for total body scans, abdominal aortic aneurysm testing, CAT coronary artery scans and carotid artery evaluations to prevent disease or find important lesions early. It’s a seductive argument, and it’s a scam.
Ordinary patients don’t understand about pre-test probability and positive and negative predictive values. Indeed, all physicians were taught to consider Bayesian theory when ordering diagnostic tests. This is very tough concept for patients to grasp. A critical principle of proper diagnostic testing can be summarized in a single sentence.
If an individual is unlikely to have the medical condition under consideration, then a diagnostic test that yields a positive result is likely to be a false reading.
Here is an illustration demonstrating why patients need to understand this issue. While the forthcoming example is hypothetical, I guarantee that every physician has seen very similar patients in their practices. While the patient presented here has a presumed cardiology issue, every medical specialist and primary care physician can land in the same trap. When this occurs, patients suffer.