1. Breast feeding and risk of breast cancer in young women Women diagnosed with breast cancer between 1982 and 1985 living in 11 health regions in Britain were selected for the study if diagnosis was made before their 36th birthday. One control per case. matched for age, was selected at random from the list of the case's general practitioner. Age matching was achieved by selecting control pairs whose date of birth was at most six months apart from the respective case. A further criterion for selecting controls was that the control had to be registered at the GP's office before the diagnosis of her corresponding case pair was established. If a patient could not be interviewed. neither was their control pair. If a selected control person could not be interviewed a second was selected (and so forth until a control interview was finally obtained). Both cases and controls were limited to Caucasian females who had not had prior malignancies and were not suffering from severe mental retardation or any psychiatric conditions. Study participants were contacted in their homes by trained survey personnel between January 1984 and February 1988. Corresponding cases and controls were interviewed by the same person. Of the 1049 women who met case selection criteria. 755 (75%) could be interviewed. Of the 7'55 initially selected control pairs, 675 (89%) were willing to participate in the study. A second control pair had to be selected in 58 cases and a third in 12 cases. 1. What was the general aim of the study? 2. What was the exposure of interest? 3. What was the primary outcome measure? 4. What was the original hypothesis of the authors? 5. What potential confounding factors can you identify