Question

You are studying a new screening instrument and determine the following after screening 135 people. Of the 60 individuals who are known to have the disease, 58 screen positive. One person without the disease screens positive. Seventy-four people without the disease screen negative. What the is the efficiency of the screening test? a. 98% b. 96% c. 99% d. 44%

Answer 1

From the given information we can constuct the following table :

D represents the person has disease , WD represents person without disease.

TEST + represents the person shows positive test result and TEST - represents the person shows negative test result.

So Number of true positive (TP) = people has disease and shows test result positive = 58

Number of True negative (TN) = People without disease and shows negative test result = 74

Number of False positive ( FP) = People without disease and shows positive test result = 1

Number of False negative ( FN ) = People with disease and shows negative test result = 2

Efficiency of the test = = = 132/135

Efficiency of the test = 0.9777 ~ 0.98 or 98%

So answer is a) 98%