We analyzed baseline data from the 34,208 women who were aged 35 to 59 years. We excluded women older than 59 years because their mothers were more likely to be deceased or otherwise unable to inform their daughter about early-life events. Our final study sample consisted of 33,501 women, after further excluding 24 with unknown age at menarche, 676 with missing family history questionnaires on early-life events, and 7 with missing race/ethnicity data.
