Homework SourseCalculate the Sensitivity and the Specificity of the followi
Calculate the Sensitivity and the Specificity of the following Screening test for Prostate Specific Antibodies test.
2,400 men were tested for prostate cancer. 1,979 men who actually had prostate cancer tested positive using this screening test. 21 men who did not have prostate cancer also tested positive. Of the men who tested negative. 240 were found to be cancer free.
What do these calculations (sensitivity and specifity) tell us about this test?
| With Disease | Without Disease | Total | |
| Test Positive | |||
| Test Negative | |||
| Total |
Solution
Sensitivity = true positives/(true positive + false negative)
= 1979/(1979+160) = 0.9252
-----------------------------
Specificity=true negatives/(true negative + false positives)
= 240/261
=0.9195
| With Disease | Without Disease | Total | |
| Test Positive | 1979 | 21 | 2000 |
| Test Negative | 160 | 240 | 400 |
| Total | 2139 | 261 | 2400 |
