So you are certainly correct but you can also tighten up your definitions for true positives as you have more information on your false positives. There may exist additional signal as well.
To your point though I think there is a difference between collecting and evaluating additional data sources and using them as diagnostic tools.
I suppose I fundamentally disagree with the implication of your post that there is no value in gathering further data for these reasons, it would seem to suggest we’re already diagnostically optimal and could not do better with additional signal.
Sure collecting more data makes sense. We agree there. If that gets you to the required degree of statistical confidence my argument is moot.
Positive for what, exactly? Quoting convnet, above:
> The downside, and the reason why most doctors do not recommend full body scans, is that every human body is a bit weird and there will almost always be something "wrong" that will be visible in a full body scan. This can lead to unnecessary testing, anxiety, and even unnecessary procedures. Many of these oddities flagged by the scan would never have caused any actual issues had the patient never been aware.
The fundamental problem is that you generally can't diagnose simply from shapes. Scans show shapes, shapes cause concern, concern leads to invasive procedures, results are negative.
Also, overdependency on "spas" for health information could lead to an atrophy of other sorts of medical information gathering and diagnosis. e.g., there's no mention in the dreamy description of this spa experience of getting a blood draw or a patellar reflex test.
The root comment is talking about adding blood, breath, urin, spit... analysis. For body imaging only I agree with you. But if we add all this, I guess we'd be able to rule out many false positives
Your "guess" is not merely incorrect but logically invalid ... such added tests (which ex hypothesi are all negative) have no bearing on false positives from tomography.