Question

validity of a test

HELP

answer ALL you can !!

... imagine you are a physician discussing the results of a screening test with a patient. AC 1) If the test was positive, how likely is it that he really has the disease? [How worried should he be?] 2) If the test was negative, how likely is it that he really does NOT have it? (How reassured should he be?] 1) What does 1) represent? 0 1 Represents that the test ran on the patient was positive and it is very likely that the patient has the disease. O True positive a) Express this measure mathematically in term of type of test results. o alats) 2) What does 2) represent? o 2 represents that the test ran on patient was negative and its unlikely that the patient has the disease o True negative a) Express this measure mathematically in term of type of test results. od/(d+b)

Answer 1

1) 1 represents that the test ran on the patient was positive and it is very likely that the patient has the disease

2) 2 represents that the test ran on the patient was negative and it is unlikely that the patient has the disease.

3) The value 132 is true positive

The value 63650 is true negative

Sensitivity - TP/ TP+ FN

False negative - 45

= 132/ (132+45)

° 0.7%

Specificity - TN /TN+FP

False positive -983

= 63650/(63650+983)

= 0.9%