About the Authors

Gemma Lasseter

Roles Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Project administration, Resources, Validation, Visualization, Writing – original draft, Writing – review & editing

gemma.lasseter@bristol.ac.uk

Affiliation Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom

Hareth Al-Janabi

Contributed equally to this work with: Hareth Al-Janabi, Caroline L. Trotter, Fran E. Carroll

Roles Conceptualization, Formal analysis, Methodology, Visualization, Writing – review & editing

Affiliation Institute of Applied Health Research, University of Birmingham, Birmingham, United Kingdom

Caroline L. Trotter

Contributed equally to this work with: Hareth Al-Janabi, Caroline L. Trotter, Fran E. Carroll

Roles Conceptualization, Formal analysis, Methodology, Visualization, Writing – review & editing

Affiliation Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom

Fran E. Carroll

Contributed equally to this work with: Hareth Al-Janabi, Caroline L. Trotter, Fran E. Carroll

Roles Conceptualization, Formal analysis, Methodology, Visualization, Writing – review & editing

Affiliation Royal College of Obstetricians and Gynaecologists, London, United Kingdom

Hannah Christensen

Roles Conceptualization, Formal analysis, Funding acquisition, Methodology, Visualization, Writing – review & editing

Affiliation Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom

Competing Interests

HC reports receiving honoraria from Sanofi Pasteur, and consultancy fees from IMS Health, AstraZeneca and GSK all paid to her employer. HA reports receiving personal fees to attend a workshop organised by GSK. CT reports receiving personal fees from GSK and Sanofi Pasteur. This does not alter the authors’ adherence to PLOS ONE policies on sharing data and materials.