About the Authors

Aluísio J. D. Barros

abarros@equidade.org

Affiliation Postgraduate Program in Epidemiology, Federal University of Pelotas, Pelotas, Brazil

Cesar G. Victora

Affiliation Postgraduate Program in Epidemiology, Federal University of Pelotas, Pelotas, Brazil

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Analyzed the data: AJB CGV. Wrote the first draft of the manuscript: AJB CGV. Contributed to the writing of the manuscript: AJB CGV. ICMJE criteria for authorship read and met: AJB CGV. Agree with manuscript results and conclusions: AJB CGV.