Question

In: Math

Canadian male has recently had a Prostate Specific Antigen (PSA) test as to determine if he...

Canadian male has recently had a Prostate Specific Antigen (PSA) test as to determine if he has prostate cancer. The false-positive rate of a PSA test is 14%. If he does have prostate cancer, PSA test will be positive 79% of the time.

Because this male is showing symptoms that are consistent with prostate cancer, it is assumed that the chance he has prostate cancer prior to taking the PSA test is 0.17.

Part (a) What is the probability that the PSA test will yield a positive result?

(use four decimals in your answer)

Part (b) If the PSA test gives a positive result, what is the probability that he does not have prostate cancer?

(use four decimals)

Part (c) Suppose the PSA test result is negative, indicating that he does not have prostate cancer and his symptoms are a result of something else. What is the probability that he does have prostate cancer?

(use four decimals)

Solutions

Expert Solution

P(false-positive) = P(tests positive | don't have cancer) = 0.14

P(tests positive | have cancer) = 0.79

P(has cancer) = 0.17

a) P(tests positive) = P(tests positive | have cancer) * P(have cancer) + P(tests positive | don't have cancer) * P(don't have cancer)

                               = 0.79 * 0.17 + 0.14 * (1 - 0.17)

                               = 0.2505

b) P(don't have cancer | tests positive) = P(tests positive | don't have cancer) * P(don't have cancer) / P(tests positive)

                                                              = 0.14 * (1 - 0.17) / 0.2505

                                                              = 0.4639

c) P(tests negative | have cancer) = 1 - P(tests positive | have cancer) = 1 - 0.79 = 0.21

P(have cancer | tests negative) = P(tests negative | have cancer) * P(have cancer) / P(tests negative)

                                                   = 0.21 * 0.17 / (1 - 0.2505)

                                                   = 0.0476


Related Solutions

Mr. Wilson is a 64 year old male. He recently learned that he has chronic Kidney...
Mr. Wilson is a 64 year old male. He recently learned that he has chronic Kidney Disease Stage IV. He is visiting with you and his nephrologist for the first time today. Dr. Phillips, the nephrologist, met with Mr. Wilson and performed an initial assessent. Following the initial intake and assessment Dr. Phillips recognizes that Mr. Wilson is in need of diet education and recommends that he visit with you, the registered nurse, for nutritional advice. Initial Assessment Height 6'2...
Carlton Bates is a 62-year-old male with a family history of prostate cancer. He requested screening...
Carlton Bates is a 62-year-old male with a family history of prostate cancer. He requested screening and his PSA level was 6.2 ng/mL. He chose to have a biopsy and is now meeting with an oncologist to discuss the results. The provider reports the biopsy was positive for malignancy: Stage 1, Gleason Score 5, classified as low risk, localized cancer. After listening to the options for treatment, Mr. Bates chooses active surveillance. a. What measures are included in active surveillance...
A researcher conducted a test to determine how sleep influenced learning. He had three conditions: normal...
A researcher conducted a test to determine how sleep influenced learning. He had three conditions: normal sleep, reduced sleep, and no sleep. Mean performance scores for the Normal Sleep, Reduced Sleep, and No Sleep groups were 18.0, 16.6, and 15.6, respectively. His F ratio was 0.97. Therefore, he concluded that those who sleep perform better than those who have reduced sleep, who perform better than those with no sleep. List two problems with this scenario, why are they problems.
         21. Unauthorized Access. Ted Munice has recently been fired. He had been the...
         21. Unauthorized Access. Ted Munice has recently been fired. He had been the payroll accountant at Texas Shipping in Galveston, Texas. The systems administrator had determined that someone had logged into the payroll system twice on December 25. A forensic investigator hired by Texas Shipping questioned Ted. Ted admitted that he had logged onto the network, but denied that he had done anything while on the network. The Company wants to take legal action against Ted and...
A specific test that a researcher could perform in order to determine if a child is...
A specific test that a researcher could perform in order to determine if a child is egocentric would be to
A screening test for prostate cancer has been shown to increase mean survival time by 5...
A screening test for prostate cancer has been shown to increase mean survival time by 5 years, and patients diagnosed via screening have demonstrated a better response to treatment than those not detected by screening. Would you determine this screening program a success? Why/why not? Provide at least 3 detailed reasons for your answer.
A male in his 80s was referred for an evaluation. He had previously been diagnosed with...
A male in his 80s was referred for an evaluation. He had previously been diagnosed with Alzheimer’s dementia. At the time of evaluation, he was living at home with assistance from his family and caregiver. He is now unable to learn most any new information, and long-term memories are also weak (sometimes forgetting who his wife and children are). He is sometimes hard to understand due to slurring of words, and he appears to see people who are not in...
A male in his 80s was referred for an evaluation. He had previously been diagnosed with...
A male in his 80s was referred for an evaluation. He had previously been diagnosed with Alzheimer’s dementia. At the time of evaluation, he was living at home with assistance from his family and caregiver. He is now unable to learn most any new information, and long-term memories are also weak (sometimes forgetting who his wife and children are). He is sometimes hard to understand due to slurring of words, and he appears to see people who are not in...
A 45-year-old male Black patient has had Type2 diabetes for 5 years. He is a long-haul...
A 45-year-old male Black patient has had Type2 diabetes for 5 years. He is a long-haul truck driver. His trips frequently have him driving 12 to 14 hours per day. His current diet consists of fast food, high fat and high carbohydrate foods, high sodium intake and minimal vegetable consumption. He does not exercise and has smoked one pack of cigarettes a day since his early twenties. List all of his risk factors, modifiable and non-modifiable for his diabetes and...
Robert is a 62 year old male who recently retired from an aircraft manufacturing company. He...
Robert is a 62 year old male who recently retired from an aircraft manufacturing company. He is at the health care provider's (HCP) clinic for a follow-up visit. He has a history of diabetes mellitus type 2, hypertension (high blood pressure) and chronic obstructive pulmonary disease (COPD). He stopped smoking 5 years ago, but had smoked a pack a day for 35 years. He has been taking metformin (Glucophage) orally twice a day at the maximum dose and long acting...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT