Ebrahim Shah, Davey Smith George
Department of Non-communicable Disease Epidemiology, London School of Hygiene & Tropical Medicine, London,UK and MRC Centre for Causal Analyses in Translational Epidemiology, University of Bristol, Bristol, UK.
Int J Epidemiol. 2013 Aug;42(4):1022-6. doi: 10.1093/ije/dyt105.