WBR0391
| Author | [[PageAuthor::Rim Halaby, M.D. [1]]] |
|---|---|
| Exam Type | ExamType::USMLE Step 1 |
| Main Category | MainCategory::Biostatistics/ Epidemiology |
| Sub Category | SubCategory::Renal |
| Prompt | [[Prompt::A case-control study is interested in finding the association between the current use of non-steroidal anti-inflammatory drugs (NSAIDs) for more than 1 year and impaired renal function. 2000 men and women above the age of 50 are surveyed. The results of the study have been categorized in the following table. What is the odds ratio for having renal impairment among patients who have a history of NSAID use versus those who do not use NSAIDs?
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| Answer A | AnswerA::0.041 |
| Answer A Explanation | [[AnswerAExp::0.041 is the attributable risk. It is calculated by the following equation:
Attributable Risk = (a/[a+b]) – (c/[c+d])]] |
| Answer B | AnswerB::0.500 |
| Answer B Explanation | AnswerBExp::0.500 does not correspond to any value. |
| Answer C | AnswerC::1.066 |
| Answer C Explanation | [[AnswerCExp::1.066 is the relative risk (RR). It is used in cohort studies. It is calculated by the following equation:
RR = (a/[a+b]) / (c/[c+d])]] |
| Answer D | AnswerD::1.200 |
| Answer D Explanation | AnswerDExp::1.200 correctly corresponds to the odds ratio. |
| Answer E | AnswerE::1.500 |
| Answer E Explanation | AnswerEExp::1.500 does not correspond to any value. |
| Right Answer | RightAnswer::D |
| Explanation | [[Explanation::Odds ratio (OR) is calculated using the equation:
OR = ad/bc = (800 x 300)/(400 x 500) = 240000/200000 = 1.2 Education Objective:
Odds ratio is calculated using the equation: OR = ad/bc |
| Approved | Approved::No |
| Keyword | |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |
