[1] Erasmus MC, Rotterdam, Netherlands
[2] Aarhus Univ Hosp, Dept Clin Epidemiol, Aarhus, Denmark
[3] Univ Oxford, Ctr Stat Med, NDORMS, Oxford, England
[4] Italian Coll Gen Practitioners & Primary Care, Hlth Search, Florance, Italy
[5] Univ Padua, Dept Women & Child Hlth, Padua, Italy
[6] Italian Coll Gen Practitioners & Primary Care, PedianetSearch, Padua, Italy
[7] GlaxoSmithKline, Global Resp Franchise, Res Triangle Pk, NC USA
[8] GlaxoSmithKline, Res & Dev, Res Triangle Pk, NC USA
[9] Ghent Univ Hosp, Dept Resp Med, Ghent, Belgium
[10] GSK, Real World Evidence & Epidemiol, Upper Providence, PA USA