Question

Question 16 (1 point) The Table belowillustrates a study conducted to determine the diagnostic value of CA-125 in the diagnosis of ovarian cancer. CA-125 test results Results greater than 212 ng/ml Results greater than 212 ng/ml Patient Population 6 65 Ovarian Cancer 56 785 Healthy population From the above data calculate the specificity of the test? a) 90.5 % b) 93.3 % c) 96.7 % d) 89.8 %

Answer 1

To calculate the specificity of the test is to measure the true rate of persons who do not have the disease in a population or given samples.

In the given test results for CA-125 for ovarian cancer, we have to know the true positives (TP) true negatives (TN), false positives (FP) and false negatives (FN)

TP = 65

FP = 56

FN = 6

TN = 785

Specificity = True negative $\div$ True negative + False positive

                 = 785 $\div$ 785 + 56

                 = 93.3%

Option b) is correct answer.