Most accurate statement

[K06100]

A group of researchers at the state university
conducts a study investigating the relationship
between cigarette smoking and vascular dementia.
Retrospective data are obtained from a
cross-sectional survey on smoking habits and
later neurologic symptoms as observed by close
relatives. Researchers fi nd that smokers are
four times as likely as nonsmokers to suffer
from vascular dementia and that they also consume
twice as much alcohol as nonsmokers in
their study. Which of the following statements
could be accurately made on the basis of the
available information?

(A) Both alcohol and cigarettes independently
increase the risk for vascular dementia
(B) Drinking alcohol increases the risk for vascular
dementia
(C) Smokers are more likely to drink than nonsmokers
(D) Smoking cigarettes increases the risk for
vascular dementia
(E) Smoking increases the risk for vascular dementia,
but alcohol has no effect on the
risk

[Novobiocin]

(C) Smokers are more likely to drink than nonsmokers

You cannot have causality from a retrospective study, only association

[K06100]

Originally Posted by Novobiocin

You cannot have causality from a retrospective study, only association

Sir, After reading this line of urs , I opened KLN behavior science step 1 chapter 1 page 13 table 1-8 ....thrs written that retrospective studies can tell about the causality......!!!!!

[Novobiocin]

Originally Posted by K06100

After reading this line of urs , I opened KLN behavior science step 1 chapter 1 page 13 table 1-8 ....thrs written that retrospective studies can tell about the causality......!!!!!

You are right but only under the "Rare disease assumption" rule.

Read the UW QID 4109

The rare disease assumption is a mathematical assumption in epidemiologic case-control studies where the hypothesis tests the association between an exposure and a disease. It is assumed that, if the prevalence of the disease is low, then the odds ratio approaches the relative risk.
Case control studies are relatively inexpensive and less time consuming than cohort studies. Since case control studies don't track patients over time, they can't establish relative risk. The case control study can, however, calculate the exposure-odds ratio, which, mathematically, is supposed to approach the relative risk as prevalence falls.

[step_enhancer]

Answer D.......