Quote from: Annah on February 12, 2013, 09:31:12 PM
if a patient was having problems and she could not figure out what the issue was, the first thing she would do is administer some labwork (tests) regardless whether or not she would know the answer. Even if she thought she would not know the answer before hand, she would still run a battery of tests and have a peer look over the results if she was stumped.
You're misreading. It's not about whether she would know
the answer, but whether she would know what to do or have anything useful to do with the result of a specific test under consideration, in the event of any of the possible answers. If the results of a test were likely to provide no actionable result, not even the action of additional tests, then the particular test under consideration has no practical value to the patient or the doctor. Still not sure I'm stating this clearly enough. You might want to try re-reading, or maybe just show the thread to your mother. I thought I was clear earlier, but this can seem like a somewhat counter-intuitive thing for people, even those who have lived with doctors for a good part of their lives.
Maybe a specific example would be better? My ex often got approached by friends who wanted full-body MRIs, thinking that a full scan would be more likely to show up whatever might be wrong. Aside from the costs, and the fact that scanning protocols tend to be tailored to a highly specific diagnostic question, one of the reasons she almost always told them this was a bad idea was essentially what JLT1 kind of suggested, and is reflected in that doctor-friend's comment. A full body MRI could show masses and all sorts of anomalies that the doctor might then need to explore further, just because they were odd, not because there were any symptoms that led anyone to suspect anything was wrong in that location.
Having started on a hunt for zebras, the doctor might be obliged, at the very least, to suggest an intrusive biopsies, surgery or further testing to rule out things the anomaly
might be, in part, because of potential liability, but also common prudence, now that they had seen something that had a very limited chance of being something awful, and even though its potential awfulness might never show up. Few procedures come with no risk at all, so doing something where the outcome could lead to a whole chain of diagnostic tests, when there had been no specific reason to suspect anything, can lead to things like MRSA, or complications related to a test that turned out to be unnecessary, but seemed at the time to be at least borderline prudent, even if it was based off an essentially blind attempt to find something.
Now, if there were a strange set of symptoms, and all the likely causes had been ruled out by other tests, doing a full body scan might be prudent, because you still have the symptoms, and you've ruled out all the most likely causes. So going on a random search under those circumstance, might have a better chance of revealing something relevant and actionable.
This may seem odd to laypeople, but most of them have never read an MRI and have little appreciation how many people (possibly all people, especially with a full body scan) are likely to have one or more odd things, or suspicious patterns, scattered around in their bodies, most of which will remain a mystery unless someone had a symptomatic reason to go looking for them in the first place. I'm sure there are probably similar issues in each of the other sub-specialties.