In a match-paired case-control study, the authors identified 7 concordant pairs and 7 discordant pairs. Of the concordant pairs, there were 3 pairs in which both the case and the control were exposed, and 4 pairs in which neither the case nor the control was exposed. Of the discordant pairs, there were 5 pairs in which the case was exposed but the control was not exposed, and 2 pairs in which the control was exposed but the case was not exposed.
a. What is the matched-pairs odds ratio for these data?
b. Now unmatch the pairs and calculate an unmatched odds ratio.