About the Authors

David K. Humphreys

dkh25@medschl.cam.ac.uk

Affiliation Institute of Public Health, University of Cambridge, Cambridge, United Kingdom

Manuel P. Eisner

Affiliation Institute of Criminology, University of Cambridge, Cambridge, United Kingdom

Douglas J. Wiebe

Affiliation Department of Biostatistics & Epidemiology, University of Pennsylvania, Philadelphia, United States of America

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: DKH MPE. Performed the experiments: DKH MPE DJW. Analyzed the data: DKH MPE DJW. Contributed reagents/materials/analysis tools: DKH MPE DJW. Wrote the paper: DKH MPE DJW.