In a study of alcohol and oral cancer the crude relative risk is 4.0 overall but it is 2.0 for men and 2.0 for women when the sexes are considered separately.This suggests
That:

Question

Quizplus · Accepted Answer

There is confounding by sex in these data.The crude relative risk (RR) is 4.0
but when we stratify by sex the RR is 2.0 for both men and women.When the stratum‐
specific estimates differ from the crude estimate this is evidence of confounding.Note
that the estimates are the same in men and women so there is no evidence of effect
modification by sex (C); these limited data can say nothing about confounding by other
factors (B) nor about bias in general (E).The description of the RRs as 'crude' indicates
that they had not been adjusted for potential confounders (D).

In a Study of Alcohol and Oral Cancer the Crude