As part of a screening program for prostate cancer, men at a senior citizens’ center are having their blood levels of prostate-specific antigen (PSA) measured.Which of the following statements would best characterize a high positive predictive value but a low negative predictive value for this screening test?
Answers:
A. All of the men who had low PSA levels were cancer-free; several men who had high levels also remained free of prostate cancer.
B.Men who had low PSA levels also displayed false-positive results for prostate cancer; men with high levels were often falsely diagnosed with prostate cancer.
C. The test displayed low sensitivity but high specificity.
D. All of the men who had high PSA levels developed prostate cancer; several men who had low PSA levels also developed prostate cancer.

The cardiologist just informed a patient that he has a reentry circuit in the electrical conduction system in his heart. This arrhythmia is called Wolff-Parkinson-White (WPW) syndrome. After the physician has left the room, the patient asks the nurse to explain this to him. Which of the following statements most accurately describes what is happening?
Answers:
A. “You must have a large clot in one of your arteries that supply oxygenated blood to the special conduction cells in your heart.”
B.“There is an extra, abnormal electrical pathway in the heart that leads to impulses traveling around the heart very quickly, in a circular pattern, causing the heart to beat too fast.”
C. “This means that the SA node (which is the beginning of your heart’s electrical system) has been damaged and is no longer functioning normal.”
D. “For some reason, your electrical system is not on full charge, so they will have to put in new leads and a pacemaker to make it work better.”