welcome redditors!to snoo-finity ... and beyond!

NBME 24 Answers

nbme24/Block 1/Question#1

A researcher hypothesizes that exposure to more ...

Case-control study

Login to comment/vote.

 +10  upvote downvote
submitted by lsmarshall(267),

An experimental design or experimental study must have an intervention, by definition. Case-control studies are observational studies, not experimental. This question is technically incorrect. They wanted to amke a point that case-control studies are time and cost efficient since they don't require following patients over time or any resources besides reviewing/gathering information. Case series could not test this hypothesis.

Also, the wording "associated wit an increased risk" somewhat alludes to case-control studies only having the ability to find odds of an associations between exposure and outcome, but not establish causal relationship.

bigjimbo  classic nbme +1  
poisonivy  totally agree, I dont understand why the right answer is Case control since that is not experimental +  
howdywhat  am I subject to this kind of poor wording for the day of the exam? +  

 +4  upvote downvote
submitted by catch-22(42),

I woud do a retrospective cohort here. I don't think this question is correct and provides too little information to get the correct answer. "Time efficient" is the operant word here but they simply didn't consider that retrospective cohort would be a better design here as long as the variables are coded.

sherry  I agree. I was hesitating between the two choices. I still think cohort study is better regarding the "risk". I hope this kind of questions wont pop out on the real thing. +1  
soph  I think key here was they were measuring risk though +  
yex  I also chose cohort, since it is comparing a given exposure. +  
raspberryslushy  I was also thinking retrospective cohort study - just as time efficient, can look at risk, and the Q stem said the cancer was common, and I think of case-control for rare conditions. It's like they forgot a cohort study could be retrospective. +  

 +0  upvote downvote
submitted by cmun777(2),

I think the key on this question is recognizing how much "most time-efficient" jumps out in the question stem - a pretty unique thing to be specifically asking. Going off that and the fact they want to look at exposure -> outcome, by far the fastest approach would be to find people who currently have the dz in question and then just ask them if they have a previous exposure aka case-control.

 +0  upvote downvote
submitted by soph(38),

I think key here is they are investigating the hypothesis of ammount of arsenicin water increases RISK of cancer.... best way to measure risk is case control.

nbmehelp  If they were measuring risk shouldn't it be a cohort study though? By looking at first aid.. +2  
270onstep1  They both can determine risk. Key here is the time efficiency of case-control studies when compared to cohort. +  
suckitnbme  Case-control only determines odds ratio which is not calculating risk. In rare diseases the odds ratio can be used as an estimate of the risk ratio however. +  

drdoom  welcome, O great physician of the skull and oral cavity. we revere your intricate understandings of the face, jaw, maxilla and all their tiny and hidden foramina. teach us your ways. +1