It's certainly how healthcare economics works. It determines what, if any tests should be run. It also determines how many parties/independent reviews should take place for high stakes tests such as tumor identification in carcinoma.
Other high-stakes scenarios in which the same tests are run multiple times are for high-economic cost events such as drug abuse, either in the workplace, or in sports.
You even note in your response, that, In real medical practice if a physician sees a lab result that is way out of range, or significantly different from the patient's previous result, or inconsistent with other aspects of the patient's condition, then she will order a repeat of the same test in order to confirm the results. - which is exactly what I'm suggesting people have done - only with a (presumably acceptable) time delay between when the first, and later tests are required. If the results of such tests were that clinical activity had to take place quickly, then you might not have the luxury of a delay, and in which case, multiple independent test vectors would be very useful - if they were economically feasible.
What people sometimes fail to consider - if the test was worth doing once - at, say, $600 - then why wouldn't it be worth doing (at presumably much higher confidence), three times at $100? And, if people agree, "OK, for $600 and $100 that makes sense" - they have to understand, those two numbers are completely arbitrary, and can only be understood in relationship to the value of the results. Whose to say there aren't a ton of tests today that are "$100" - that couldn't be done multiple times to be certain.
Other high-stakes scenarios in which the same tests are run multiple times are for high-economic cost events such as drug abuse, either in the workplace, or in sports.
You even note in your response, that, In real medical practice if a physician sees a lab result that is way out of range, or significantly different from the patient's previous result, or inconsistent with other aspects of the patient's condition, then she will order a repeat of the same test in order to confirm the results. - which is exactly what I'm suggesting people have done - only with a (presumably acceptable) time delay between when the first, and later tests are required. If the results of such tests were that clinical activity had to take place quickly, then you might not have the luxury of a delay, and in which case, multiple independent test vectors would be very useful - if they were economically feasible.
What people sometimes fail to consider - if the test was worth doing once - at, say, $600 - then why wouldn't it be worth doing (at presumably much higher confidence), three times at $100? And, if people agree, "OK, for $600 and $100 that makes sense" - they have to understand, those two numbers are completely arbitrary, and can only be understood in relationship to the value of the results. Whose to say there aren't a ton of tests today that are "$100" - that couldn't be done multiple times to be certain.