Why is the false-positive rate for PSA screening so high?Question 3Answera.PSA is a marker for other benign prostate-related diseases in addition to prostate cancer.b.Studies have been conducted in low-risk populations, thus increasing the PPV.c.PSA is a marker for testicular cancer even without the presence of prostate cancer.d.Studies have been conducted in high-risk population, thus lowering the PPV.

There is a screening test for prostate cancer that looks at the level of PSA (prostate-specific antigen) in the blood. There are a number of reasons besides prostate cancer that a man can have elevated PSA levels. In addition, many types of prostate cancer develop so slowly that they are never a problem. Unfortunately, there is currently no test to distinguish the different types, and using the test is controversial because it is hard to quantify the accuracy rates and the harm done by false positives. For this problem, we’ll call a positive test a true positive if it catches a dangerous type of prostate cancer. We’ll assume the following numbers: The rate of prostate cancer among men over 50 = 0.0005 The true positive rate for the test = 0.9 The false positive rate for the test = 0.01 Let 𝑇 be the event a man has a positive test and let 𝐷 be the event a man has a dangerous type of the disease. Find 𝑃(𝐷|𝑇 ) and 𝑃(𝐷|𝑇𝑐).

. A gene test shows promising results in providing early detection for colon cancer. However, 5% of all test results are falsely positive; that is, results indicate that cancer is present when the patient is, in fact, cancer-free. Given this false positive rate, how many people out of 10,000 would have a false positive result and be alarmed unnecessarily?

Which of the following statements is false regarding the incidence of prostate cancer?Question 2Answera.Prostate cancer is the most commonly diagnosed cancer among men in the U.S.b.Some of the lowest incidence rates of prostate cancer in the world are in Asia.c.White men have a higher incidence of prostate cancer compared to Black men.d.Developed countries have a higher incidence of prostate cancer.

define False Positive in short

It is known that a rare disease affects 1% of the population. A medical test for this disease is 99% effective, which means that if you have the disease, there is a 99% chance that the test will be positive, and if you do not have the disease, there is a 99% chance that the test will be negative.If you take the medical test and result is positive, what is the chance that you have the disease?Hint: consider a cohort of 10000 people and calculate P(having the disease AND test is positive) and P(not having the disease AND test is positive)Group of answer choices0.750.990.010.5