Author Contributions: Ms Sexton had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. Drs Morgan and Torres were both lead authors and contributed equally to this article.
Study concept and design: Morgan, Torres, Herrero, Greenberg, Ferreccio, Chey, Anderson, Baker.
Acquisition of data: Herrero, Salazar-Martínez, Bravo, Dominguez, Ferreccio, Lazcano-Ponce, Meza-Montenegro, E. Peña, R. Peña, Correa.
Analysis and interpretation of data: Morgan, Torres, Sexton, Herrero, Salazar-Martínez, Greenberg, Chey, Anderson, Crowley, Baker.
Drafting of the manuscript: Morgan, Torres, Greenberg, Anderson.
Critical revision of the manuscript for important intellectual content: Morgan, Torres, Sexton, Herrero, Salazar-Martínez, Greenberg, Bravo, Dominguez, Ferreccio, Lazcano-Ponce, Meza-Montenegro, E. Peña, R. Peña, Correa, Martínez, Chey, Valdivieso, Anderson, Goodman, Crowley, Baker.
Statistical analysis: Sexton, Anderson, Crowley.
Obtained funding: Baker, Crowley.
Administrative, technical, or material support: Morgan, Herrero, Greenberg, Dominguez, Lazcano-Ponce, Meza-Montenegro, E. Peña, Martínez, Valdivieso.
Study supervision: Greenberg.
Conflict of Interest Disclosures: All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest and none were reported.
Funding/Support: The Bill & Melinda Gates Foundation (#43930) provided financial support for the trial, and the National Institutes of Health (NIH) (CA037429) supported the SWOG (Southwest Oncology Group) administrative and statistical infrastructure.
Role of the Sponsor: The Bill & Melinda Gates Foundation conducted an external scientific review of the proposal before approving it, and the investigators later incorporated some of the reviewers' suggestions regarding the design of the study. The NIH was not directly involved in the study design, protocol execution, or analysis and reporting of data. The SWOG data coordinating center (CRAB) housed all data during the study and performed the data analyses. The decision to publish was made by the study investigators.
Additional Contributions: We thank the trial participants for making this study possible and recognize the many contributions of the investigative team members.