Define and give the formula for an odds ratio

1. Define and give the formula for an odds ratio:

2. Complete the 2 x 2 table below and calculate the Odds Ratio: There were 91 total with lung cancer of which 27 were not exposed to tobacco smoke; 173 total without lung cancer of which 56 were exposed to tobacco smoke. Show your work.

   		Disease Status
   		Yes	No
   Exposure Status	Yes	64	56
   	No	27	117

   3) Interpret the odds ratio / what does this finding mean?

   4) You are reviewing the results of a case-control study of vitamin D supplements and prostate cancer. The study had an alpha level of .05 and 95% CI. The study findings report an Odds Ratio of .49, p value = .001, 95% CI (.45 - .60).

Interpret these results: comment on the OR, p value, and CI.

5) Discuss some of the methodological limitations of the case-control study design.