3 ms·
The base rate part is just explaining why the diagnostic doesn't work when applied on a healthy population (like med students) The instruction would be somethi
by cortesoft 6y ago
The base rate part is just explaining why the diagnostic doesn't work when applied on a healthy population (like med students)
The instruction would be something like "if the patient complains of x, check for symptom y... if the have symptom y, they are likely suffering from z"
But the med student then checks themselves for symptom y, and thinks they have z, but that is only the case if they are suffering from x. The suffering from x part is what changes the base rate, and can't be ignored.
- westoncb 6y agoBut in the patient's complaint about X, wouldn't X just be another symptom? For instance, let's say a patient complains of a headache. The doctor uses whatever other knowledge they have of the patient to come up with some candidate diagnoses, and proceeds checking for symptoms from each of the candidates. Presumably 'headache' is just another symptom on the diagnostic criteria for each of the other candidates. So why is it treated specially? (Btw, thanks for your response—not sure why you were downvoted, but that was not from me!)
- cortesoft 6y agoRight, my point is that the symptom X is often an implied one.... it isn't expressed in the diagnostic test explicitly, because the diagnostic test is run only when someone has symptom x.