[1] Univ Hosp Zurich, Inst Complementary & Integrat Med, Sonneggstr 6, CH-8091 Zurich, Switzerland
[2] Univ Zurich, Zurich, Switzerland
[3] Univ Francisco de Vitoria UFV, Fac Med, Madrid, Spain
[4] Hosp Univ Ramon y Cajal, Unidad Bioestadist Clin, Inst Ramon y Cajal Invest Sanitaria IRYCIS, Madrid, Spain
[5] Univ Maryland, Ctr Integrat Med, Sch Med, Baltimore, MD USA
[6] Univ Otago Wellington, Dept Med, Wellington, New Zealand
[7] Univ Melbourne, Melbourne Sch Populat & Global Hlth, Melbourne, Vic, Australia
[8] Queens Univ Belfast, Ctr Publ Hlth, Belfast, North Ireland
[9] Keele Univ, Sch Med, Keele, Staffs, England
[10] Ctr Res & Technol Hellas, Informat Technol Inst, Thessaloniki, Greece
[11] Univ Oberta Catalunya UOC, eHlth Lab Res Grp, Barcelona, Spain
[12] IRCCS Hosp Casa Sollievo della Sofferenza, Dept Otorhinolaryngol & Maxillofacial Surg, San Giovanni Rotondo, FG, Italy
[13] Univ Hosp Foggia, Dept Otorhinolaryngol, Foggia, Italy
[14] Neu Ulm Univ Appl Sci, DigiHlth Inst, Neu Ulm, Germany
[15] Ludwig Maximilian Univ Munich, Inst Med Informat Proc Biometry & Epidemiol, Munich, Germany
[16] Univ Las Palmas Gran Canaria, Complejo Hosp Univ Insular Maternoinfantil, Endocrinol & Nutr Dept, Inst Invest Biomed & Sanitarias, Las Palmas Gran Canaria, Spain
[17] Natl Univ Singapore, Saw Swee Hock Sch Publ Hlth, Singapore, Singapore
[18] Cochrane, Cochrane Response, London, England
[19] Cincinnati Childrens Hosp Med Ctr, Div Behav Med & Clin Psychol, Cincinnati, OH USA
[20] Univ Cincinnati, Coll Med, Dept Pediat, Cincinnati, OH USA
[21] Charite, Inst Social Med Epidemiol & Hlth Econ, Berlin, Germany