About the Authors
Department of Public Health and Primary Care, Institute of Public Health, Cambridge University, Cambridge, United Kingdom
Medical Research Council Biostatistics Unit, Institute of Public Health, Cambridge, United Kingdom
Institute of Psychiatry, King's College London, London, United Kingdom
The authors have declared that no competing interests exist.
CB conceived this analysis and led the study. LG and FEM designed and conducted the analysis. MD contributed at all stages. All authors discussed the results and commented on the paper. All MRC CFAS (corporate author) principle investigators and team were involved in the study and had an opportunity to comment on the paper.