Ona McCarthy1, Rebecca S French2, Ian Roberts3, Caroline Free3. 1. Department of Population Health, London School of Hygiene and Tropical Medicine, Keppel St, London, WC1E 7HT, UK. ona.mccarthy@lshtm.ac.uk. 2. Department of Social and Environmental Health Research, London School of Hygiene and Tropical Medicine, 15-17 Tavistock Place, London, WC1H 9SH, UK. 3. Department of Population Health, London School of Hygiene and Tropical Medicine, Keppel St, London, WC1E 7HT, UK.
Unfortunately, the original version of this article [1] contained an error. There were errors in the reference numbers in Additional file 1. This has now been corrected and Additional file 1 is included here with the correct reference numbers.