About the Authors
The authors have declared that no competing interests exist.
J-PG co-ordinated the project, compiled the studies, wrote the plan of analysis, analysed the data, and wrote the paper. FC had a crucial role in the analysis and interpretation of results and gave significant input in the writing of the paper. IvdB, SB, MvH, EC, OB, and J-MK compiled data from their MSF section and contributed in data interpretation. SV participated in the analysis and interpretation of part of the data and had a crucial role in paper writing. DL had an important role in the conception, analysis, and interpretation of several individual studies and had an important intellectual contribution to the overall intervention, to which he gave important epidemiological input. PJG contributed in the conception of the project, in the interpretation of results, and in the writing of the paper. All authors participated intellectually in this project and in the writing of the paper.