About the Authors

Patricia J. Lucas

patricia.lucas@bristol.ac.uk

Affiliation School for Policy Studies, University of Bristol, Bristol, United Kingdom

Christie Cabral

Affiliation School for Social and Community Medicine, University of Bristol, Bristol, United Kingdom

John M. Colford Jr.

Affiliation Division of Epidemiology, School of Public Health, University of California, Berkeley, California, United States of America

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: PJL CC JMC. Analyzed the data: PL CC. Wrote the paper: PJL CC JMC.