WBR0793: Difference between revisions
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|MainCategory=Biostatistics/ Epidemiology | |MainCategory=Biostatistics/ Epidemiology | ||
|SubCategory=Reproductive | |SubCategory=Reproductive | ||
|Prompt=A new urine pregnancy test is being studied before being distributed to pharmacies. A trial is conducted to compare the results of this new test to a combination of imaging and blood HCG levels to validate the pregnancy. A table showing the results | |Prompt=A new urine pregnancy test is being studied before being distributed to pharmacies. A trial is conducted to compare the results of this new test to a combination of imaging and blood HCG levels to validate the pregnancy. A table showing the results of the study is shown below. What is the probability that a woman is really pregnant if her urine pregnancy test result comes back positive? | ||
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[[Image:Biostat.png|600px]] | [[Image:Biostat.png|600px]] | ||
Educational Objective: Positive predictive value (PPV) = [True positive/(True positive+False positive)] | |||
|AnswerA=85.71% | |AnswerA=85.71% | ||
|AnswerAExp=This refers to the sensitivity. | |AnswerAExp=This refers to the sensitivity. | ||
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|AnswerDExp=This refers to the specificity. | |AnswerDExp=This refers to the specificity. | ||
|AnswerE=62% | |AnswerE=62% | ||
|AnswerEExp=This does not refer to any particular value. | |||
|RightAnswer=B | |RightAnswer=B | ||
|WBRKeyword=Positive predictive value | |WBRKeyword=Positive predictive value | ||
|Approved=No | |Approved=No | ||
}} | }} | ||
Revision as of 01:56, 31 October 2013
| Author | [[PageAuthor::Rim Halaby, M.D. [1]]] |
|---|---|
| Exam Type | ExamType::USMLE Step 1 |
| Main Category | MainCategory::Biostatistics/ Epidemiology |
| Sub Category | SubCategory::Reproductive |
| Prompt | [[Prompt::A new urine pregnancy test is being studied before being distributed to pharmacies. A trial is conducted to compare the results of this new test to a combination of imaging and blood HCG levels to validate the pregnancy. A table showing the results of the study is shown below. What is the probability that a woman is really pregnant if her urine pregnancy test result comes back positive?
|
| Answer A | AnswerA::85.71% |
| Answer A Explanation | AnswerAExp::This refers to the sensitivity. |
| Answer B | AnswerB::75% |
| Answer B Explanation | AnswerBExp::This refers to the positive predictive value. |
| Answer C | AnswerC::89.28% |
| Answer C Explanation | AnswerCExp::This refers to the NPV. |
| Answer D | AnswerD::80.64% |
| Answer D Explanation | AnswerDExp::This refers to the specificity. |
| Answer E | AnswerE::62% |
| Answer E Explanation | AnswerEExp::This does not refer to any particular value. |
| Right Answer | RightAnswer::B |
| Explanation | [[Explanation::The positive predictive value is the probability that a person really has a condition if his test result is positive. The calculation is shown below.
Educational Objective: Positive predictive value (PPV) = [True positive/(True positive+False positive)] |
| Approved | Approved::No |
| Keyword | WBRKeyword::Positive predictive value |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |
