Page 1 of 1: Q: Biostatistics: reference interval

doctorgirl78 · Credits: 5336 My Scrapbook

1) A biochemical assay for a newly-discovered hormone is stated to have a reference interval of between 0 and 7 picog/dl. Suppose now that this reference interval is (arbitrarily) reduced to between 0 and 3 picog/dl.The effect of reducing the reference interval will be to:

One answer only.

A. Increase the test's specificity.
B. Decrease the number of false-positive results.
C. Increase the number of false-negative results.
D. Increase the sensitivity of the test.
E. Not alter the test's sensitivity or specificity.

why is choice two not as good as the answer given

Bruno · Credits: 44624 My Scrapbook My Reading List 50 Books

A biochemical assay for a newly-discovered hormone is stated to have a reference interval of between 0 and 7 picog/dl. Suppose now that this reference interval is (arbitrarily) reduced to between 0 and 3 picog/dl.The effect of reducing the reference interval will be to:

One answer only.

A. Increase the test's specificity.
B. Decrease the number of false-positive results.
C. Increase the number of false-negative results.
D. Increase the sensitivity of the test.
E. Not alter the test's sensitivity or specificity.

doctorgirl78 · Credits: 5336 My Scrapbook

hey this ques tion has been directly picked from NMS review series for USMLE step 2 and heres what the answer and the explanation in it says:

narrowing the reference interval of a test 0-7 to 0-3 increases the test's SENSTIVITY.because there wil be fewer false negatives.however increasing the senstivity will automatically decrease SPECIFICITY by increasing the number of fasle positives.

		Sign In New User? Sign Up Sign in to access your control panel and messenger!
				TechZone \| SpiderNevi \| HowTo? \| Scrapbook!