[1] McMaster Univ, Dept Med, Hamilton, ON, Canada
[2] McMaster Univ, Div Respirol, Hamilton, ON, Canada
[3] Merck Canada Inc, Toronto, ON, Canada
[4] Southmount Hlth Care Ctr, Stoney Creek, ON, Canada
[5] Dalhousie Univ, Dept Med, Div Respirol, Halifax, NS, Canada
[6] Western Univ, Dept Clin Immunol & Allergy, London, ON, Canada
[7] McGill Univ, Royal Victoria Hosp, Montreal, PQ, Canada
[8] Canadian Heart Res Ctr, Toronto, ON, Canada
[9] Queens Univ, Dept Med, Div Allergy & Immunol, Kingston, ON, Canada
[10] Univ Laval, Quebec Heart & Lung Inst, Quebec City, PQ, Canada
[11] Univ Toronto, Dept Family & Community Med, Toronto, ON, Canada
[12] Univ Calgary, Cumming Sch Med, Dept Med, Calgary, AB, Canada
[13] St Josephs Healthcare, Firestone Inst Resp Hlth, Hamilton, ON, Canada
[14] McMaster Univ Med Ctr, 3U9,1280 Main St West, Hamilton, ON L85 4LA, Canada