10-27-2007, 07:49 PM
10. A study is conducted to assess the
effectiveness of a new blood
test for early detection of prostate cancer. Ten
thousand healthy men
over the age of 50 years are randomly assigned to
receive either annual
rectal examination or annual screening with the new
blood test. After
5 years, results show that of the 50 men in the blood
test group that
were diagnosed with prostate cancer, 40 were living 2
years after the
diagnosis was made. In comparison, only 15 out of 45
men in the rectal
examination group survived 2 years after being
diagnosed with prostate
cancer. Researchers conclude that the blood test
increases survival
compared with rectal examination. Which of the
following potential flaws
is most likely to invalidate this conclusion?
A
) Age of the patients
B
) Diagnostic bias
C
) Lead time bias
D
) Recall bias
E
) Type II error
effectiveness of a new blood
test for early detection of prostate cancer. Ten
thousand healthy men
over the age of 50 years are randomly assigned to
receive either annual
rectal examination or annual screening with the new
blood test. After
5 years, results show that of the 50 men in the blood
test group that
were diagnosed with prostate cancer, 40 were living 2
years after the
diagnosis was made. In comparison, only 15 out of 45
men in the rectal
examination group survived 2 years after being
diagnosed with prostate
cancer. Researchers conclude that the blood test
increases survival
compared with rectal examination. Which of the
following potential flaws
is most likely to invalidate this conclusion?
A
) Age of the patients
B
) Diagnostic bias
C
) Lead time bias
D
) Recall bias
E
) Type II error