[1] McMaster Univ, Michael G De Groote Sch Med, St Josephs Healthcare, Firestone Inst Resp Hlth, Hamilton, ON, Canada
[2] McMaster Univ, Michael G De Groote Sch Med, Dept Med, Hamilton, ON, Canada
[3] Jagiellonian Univ, Med Coll, Dept Internal Med 2, Ctr Evidence Based Med, Ul Skawinska 8, PL-31066 Krakow, Poland