To the Editor.
—Dr Morrison and colleagues1 take little or no note of what I find to be a very important aspect of the data presented in their article. The folate data for men (in Table 3) show a relative risk (RR) of 1.36 (95% confidence interval [CI], 0.80-2.31) for those in the lowest quartile when compared with those in the highest quartile. In contrast, the data for women (presented in Table 4) show an RR of 2.83 (95% CI, 1.30-6.18) for women in the lowest quartile as compared with those in the highest quartile.Although the authors mention these data, they also comment that, "there was no statistically significant interaction by sex." I am unable to find anything in the article to justify this statement. Moreover, in the "Comment," the authors state, "It is not known if the increased RR in women as compared with men was a