A screening test for a newly discovered disease is being evaluated. In order to determine the effectiveness of the new test, it was administered to 900 workers. 150 of the individuals diagnosed with the disease tested positive. A negative test finding occurred in 60 people who had the disease. A total of 50 persons not diseased tested positive for it. Assume the prior probability is not known. Create a 2 x 2 table for this data:
True Disease Status
Test Result Present Not Present
Positive TP FP
Negative FN TN
TP + FN FP + TN
1. What is the prevalence rate of the disease?
2. What is the sensitivity of the test?
3. What is the specificity of the test?
4. What is the percentage of false negatives?
5. What is the percentage of false positives?
6. What is the accuracy of the test?