About the Authors

Debbie A Lawlor, Abigail Fraser, George Davey Smith
Department of Social Medicine, 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

d.a.lawlor@bristol.ac.uk

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

DAL, SE, and GDS designed the study. DAL analyzed the data and enrolled patients. All authors contributed to writing the paper. AF made a substantial contribution to interpreting results.