[1] Ente Osped Cantonale, Pediat Inst Southern Switzerland, Bellinzona, Switzerland
[2] Univ Svizzera Italiana, Lugano, Switzerland
[3] Univ Svizzera Italiana, Family Med Inst, Lugano, Switzerland
[4] Ente Osped Cantonale, Dept Internal Med, Lugano, Switzerland
[5] Univ Lausanne, Ctr Hosp Univ Vaudois, Dept Pediat, Pediat Cardiol Unit, Lausanne, Switzerland
[6] Fdn IRCCS Ca Granda Osped Maggiore Policlin, Pediat Unit, Milan, Italy
[7] Univ Milan, Dept Clin Sci & Community Hlth, Milan, Italy