Question

In a case-control study of maternal cigarette smoking as a risk factor for low birth weight, the investigators concluded that mothers of children with low birth weight were more likely to report smoking during pregnancy relative to mothers of children with normal birth weight. The investigators later learned there was a reporting error, in which the mothers of healthy weight babies who smoked while pregnant tended to not report the fact that they smoked; in other words, they did not recall having smoked. The reporting error most likely caused the odds ratio to: a. Increase above the true value b. Decrease below the true value but remain positive c. There was no change in the odds ratio from the true value d. Change direction such that smoking prevented low birth weight e Equal the relative risk

can the answer please be given

ive answered E before and it was incorrect

Answer 1

Page consider following 242 contingency Table smoked Non-smoked low weight a Normal birth weight b odds ratio = (a/b) - ab ad be But actually (suppose) n, mothers having healthy babies not reported the fact that they smoke Hence b = btn nd d = don . odds ratio = a (d-n) ccbrn) ad a cd-n) ccbtn. bo - the hue value but remain Decrease below positive