Author contributions
FG, JMG, CD, MF, CO, AF, JL and BC devised the study concept and design. JL was responsible for overseeing the statistical section. FG, JMG, JL and BC have been involved in drafting the manuscript or revising it critically for important intellectual content. FG and BC supervised the entire work. All authors (FG, JMG, CD, HC, MF, FL, RMC, TL, CO, AF, AM, GE, CL, CSe, DA, AJ, JG, KG, AL, GG, CDP, CSa, JL, BC) have given final approval of the version to be published. Each author has participated sufficiently in the work to take public responsibility for appropriate portions of the content.