About the Authors
- Christa L. Fischer Walker, Robert E. Black
- Johns Hopkins Bloomberg School of Public Health, Department of International Health, Baltimore, Maryland, United States of America
- Olivier Fontaine
- World Health Organization, Geneva, Switzerland (Retired)
The authors have declared that no competing interests exist.
Wrote the first draft of the manuscript: CLFW. Contributed to the writing of the manuscript: REB OF. ICMJE criteria for authorship read and met: CLFW REB OF. Agree with manuscript results and conclusions: CLFW REB OF.