Testing Thresholds Flashcards
T/F: Every test has a cost (e.g., time spent, money, radiation)
True
What is a testing threshold?
When we stop investigating based on the balance of the benefit from further information & the harm of further investigation
If the probability of disease is above the testing threshold, what is needed, what zone is this called, what are differentials called here?
- Further testing (questions, physical exams, labs, etc.) is needed to move the probability past a threshold
- “Test” zone
- “active alternatives”
T/F: Threshold is objective
False
What are factors determining where threshold is?
- condition: harms of ruling out a diagnosis
- test: accuracy (good or low LR), harms (financial, time spent, etc.)
What do you want to balance when determining a threshold?
balance of harms and benefits
T/F: Should not set the testing threshold below the population prevalence
True
Should usually not set the testing threshold below the population prevalence, why?
is would suggest that you think someone taken at random from the population is in the “testing” zone, implying at least that you think everyone who walks into your office should be investigated for the condition
When does the test zone expand and trash zone shrinks?
- Greater harm of ruling out the condition if it is present
- More favorable balance of test harm relative to information benefit
When does the trash zone expand and test zone shrinks?
- Less harm of ruling out the condition if it is present
- Less favorable balance of test harm relative to information benefit
Testing thresholds set a probability below which we?
stop diagnostic work-up
Testing thresholds are set according to what?
harm of inappropriately ruling out a diagnosis and the balance of the harms and benefits of testing
When the probability of disease is above a testing threshold, what is needed?
further testing or other management
When the probability of disease is below a testing threshold, what is needed?
stop diagnostic work-up for that condition
