WBR0391: Difference between revisions

Jump to navigation Jump to search
Rim Halaby (talk | contribs)
Created page with "{{WBRQuestion |QuestionAuthor={{Rim}} |ExamType=USMLE Step 1 |MainCategory=Biostatistics/ Epidemiology |SubCategory=Renal |MainCategory=Biostatistics/ Epidemiology |SubCategor..."
 
Rim Halaby (talk | contribs)
No edit summary
Line 21: Line 21:
|SubCategory=Renal
|SubCategory=Renal
|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?
|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?
[[Image:NSAID use WBR.png]]
|Explanation=Odds ratio (OR) is calculated using the equation:  
|Explanation=Odds ratio (OR) is calculated using the equation:  
OR = ad/bc = (800 x 300)/(400 x 500) = 240000/200000 = 1.2
OR = ad/bc = (800 x 300)/(400 x 500) = 240000/200000 = 1.2
Line 26: Line 28:
Education Objective:
Education Objective:
Odds ratio is calculated using the equation: OR = ad/bc
Odds ratio is calculated using the equation: OR = ad/bc
|AnswerA=0.041
|AnswerA=0.041
|AnswerAExp=0.041 is the attributable risk.  It is calculated by the following equation:  
|AnswerAExp=0.041 is the attributable risk.  It is calculated by the following equation:  
Attributable Risk = (a/[a+b]) – (c/[c+d])  
Attributable Risk = (a/[a+b]) – (c/[c+d])
|AnswerB=0.500
|AnswerB=0.500
|AnswerBExp=0.500 does not correspond to any value.
|AnswerBExp=0.500 does not correspond to any value.
Line 35: Line 36:
|AnswerCExp=1.066 is the relative risk (RR).  It is used in cohort studies.  It is calculated by the following equation:
|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])
RR = (a/[a+b]) / (c/[c+d])
|AnswerD=1.200
|AnswerD=1.200
|AnswerDExp=1.200 correctly corresponds to the odds ratio.
|AnswerDExp=1.200 correctly corresponds to the odds ratio.

Revision as of 03:05, 10 September 2013

 
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?

]]

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
Educational Objective:
References: ]]

Approved Approved::No
Keyword
Linked Question Linked::
Order in Linked Questions LinkedOrder::