About the Authors

Tini Garske

To whom correspondence should be addressed. E-mail: t.garske@imperial.ac.uk

Affiliations Department of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom, Institute for Mathematical Sciences, Imperial College London, London, United Kingdom

Paul Clarke

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

Azra C. Ghani

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

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Analyzed the data: TG. Other: Initiated the research, obtained the datasets and wrote the outline of the paper: AG. Programmed and performed the data analysis and wrote the first draft of the paper: TG. Developed the statistical methods for calculating the confidence intervals: PC.