About the Authors

George Davey Smith, Debbie A Lawlor, Roger Harbord, Nic Timpson, Ian Day
Department of Social Medicine, University of Bristol, Bristol, United Kingdom

George Davey Smith, Debbie A Lawlor, Nic Timpson, Ian Day
Medical Research Council Centre for Causal Analyses in Translational Epidemiology, University of Bristol, Bristol, United Kingdom

Shah Ebrahim
Department of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom

Corresponding Author

george.davey-smith@bristol.ac.uk

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

GDS, SE, and ID designed the study. DAL and RH analyzed the data. DAL and SE enrolled patients. GDS, DAL, RH, NT, ID, and SE contributed to writing the paper.