[1] Univ Complutense Madrid, Inst Invest Sanitaria Gregorio Maranon IiSGM, Hosp Gen Univ Gregorio Maranon, Resp Care Dept, Madrid 28040, Spain
[2] Univ Complutense Madrid, Fac Nursing Physiotherapy & Podol, Madrid 28040, Spain
[3] Univ Complutense Madrid, Fac Med, Dept Publ Hlth & Maternal & Child Hlth, Madrid 28040, Spain
[4] Univ Castilla La Mancha, Sch Hlth Sci, Talavera De La Reina 45600, Spain
[5] Univ Rey Juan Carlos, Dept Med Specialties & Publ Hlth, Prevent Med & Publ Hlth Teaching & Res Unit, Madrid 28922, Spain