Received: 10 July 2020
Revised: 23 December 2020
Accepted: 13 January 2021
First Online: 24 March 2021
Ethics approval and consent to participate
: The study protocol was approved by the institutional review boards of Brigham and Women’s Hospital and Harvard T.H. Chan School of Public Health (Boston, MA, USA).
: Completion of the questionnaire was considered to imply informed consent when the study protocol was approved in 1976 (NHS) and 1989 (NHSII) by the institutional review boards of the Brigham and Women’s Hospital (Boston, MA, USA) and Harvard T.H. Chan School of Public Health (Boston, MA, USA), and those of participating registries as required. The studies were conducted in accordance with recognised ethical guidelines (Declaration of Helsinki).
: The datasets used and analysed during this study are available from the corresponding author on reasonable request.
: M.D.H. reported grants from FHI Solutions, nonfinancial support from Bayer AG (Bayer supplies aspirin and placebo for the Aspirin after Breast Cancer trial) and personal fees from Arla Foods (participated in a systematic review of dietary intake in Nigerian children for this company) outside the submitted work. The remaining authors declare no competing interests.
: The study was supported by the National Institutes of Health Grants (U01 CA176726, UM1 CA186107), American Institute for Cancer Research (AICR) to M.S.F., and the Breast Cancer Research Foundation (BCRF) to W.C.W. The study sponsors were not involved in the study design and collection, analysis and interpretation of the data, or the writing of the article or the decision to submit it for publication. The authors were independent of study sponsors.