Table 1.

Baseline Sister Study data collection.

Data component	Details
First study contact	Per IRB stipulations, web-screened women were required to call the study to sign up. Data collected: age, race/ethnicity, sister, and personal breast cancer status.
Two-part computer-assisted telephone interview (CATI1 and CATI2)	Required baseline activity. Usually scheduled on different days. For same-day interviews, minimum 15-min break scheduled between CATI1 and CATI2. Data collected in CATI1: age, race/ethnicity, education; income; family size; personal history of cancer, BRCA1/2 screening; sisters’ history of cancer(s) including breast; overall health, screening behavior, breast conditions; environmental exposures and residential history including farm exposures; physical activity; sun exposure; smoking; alcohol use; sleep patterns. Questions on exposures and lifestyle factors addressed childhood and adulthood. Data collected in CATI2: occupational history and exposures including 19 occupation-specific modules; age at menarche; pregnancy and fertility data; hormone use (contraceptives and hormone therapy); medical conditions and medications; current height and weight as well as during 30s and teens and at $\sim 10\mathrm{y}$ of age.
Biometrics (examiner form)	Part of required home visit. Data collected: height, weight, hip and waist circumference; blood pressure and pulse.
Biologic and environmental specimens	Part of required home visit. Specimens collected by examiner (phlebotomist): blood (saliva for DNA if blood could not be collected). Specimens collected by participant: first morning urine; toenail clippings; dust swabs of home environment.
Past 24 h questionnaire (self-administered; paper)	This questionnaire was included in mailed kit to be filled out for the 24 h just before the examiner visit; completed questionnaire given to home visit examiner (phlebotomist). Data collected: medications, smoking, alcohol, and chemical exposures in the 24 h before blood collection; environmental exposures in the weeks preceding blood collection.
Other questionnaires (self-administered; paper) •Family history •Food frequency (Block 98) •Personal care products	Included in the study kit mailed to participants; completed questionnaires usually given to home visit examiner but could be returned later by participant. Data collected: Family history questionnaire: participants’ birth characteristics and mother’s pregnancy experiences (in utero exposures); cancer history of first-degree relatives and others; noncancer medical conditions in biological family members. Dietary questionnaire: frequency and amount of foods consumed in the last 12 months; meal patterns; complementary and alternative medicines. Personal care products questionnaire: current and childhood ($10–13\mathrm{y}$ of age) use of products such as makeup, moisturizers, other creams and lotions, acne-related products, skin lighteners or tanners, wrinkle-reducing products, talc, douches, hair care products and dyes, nail care products, mouthwash, deodorant, antiperspirant.