Figure 2. Case-Cohort Study Design .

The Breast and Bone Follow-up to the Fracture Intervention Trial (B ~ FIT) study was designed to follow-up women screened for the Fracture Intervention Trial (FIT) at 10 of the 11 participating FIT clinical centers. Vital status and cause of death of women who were screened (n = 15 595 women in B ~ FIT) was determined via linkage to the National Death Index Plus.²¹ From 2001 to 2004, surviving women who had been screened were contacted by mail and/or telephone and invited to complete a follow-up questionnaire that ascertained cancer diagnoses, other health outcomes, family history of cancer, detailed hormone use, preventive screening procedures, and reproductive surgeries that occurred since they completed the FIT health history questionnaire. The B ~ FIT questionnaire was completed by 64% of eligible women. Women included in the current case-cohort study were selected as depicted. Modified with permission from Dallal et al.²¹ IRB indicates institutional review board.

^aSubcohort randomly selected within 10-year age and clinical center strata.