title: The PD20but not the PC20in a methacholine challenge test is device independent.
authors.affiliation: Division of Respiratory Medicine, Department of Pediatrics, Physiology and Experimental Medicine, Research Institute-Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada. Electronic address: allan.coates@sickkids.ca.
authors.forename: Allan L
authors.initials: AL
authors.lastname: Coates
authors.affiliation: Division of Respiratory Medicine, Department of Pediatrics, Child Health Evaluative Sciences Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Sharon D
authors.initials: SD
authors.lastname: Dell
authors.affiliation: Division of Respirology, Critical Care, and Sleep Medicine, Royal University Hospital, Saskatoon, Saskatchewan, Canada.
authors.forename: Donald W
authors.initials: DW
authors.lastname: Cockcroft
authors.affiliation: Division of Respirology, Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Gail M
authors.initials: GM
authors.lastname: Gauvreau
mesh_terms: D000328:Adult; D001249:Asthma / Q000175:diagnosis; D001985:Bronchial Provocation Tests / Q000379:methods*; D016085:Bronchoconstrictor Agents / Q000008:administration & dosage*; D002648:Child; D005260:Female; D005541:Forced Expiratory Volume / Q000187:drug effects; D006801:Humans; D008297:Male; D016210:Methacholine Chloride / Q000008:administration & dosage*
chemical_list: D016085:Bronchoconstrictor Agents; D016210:Methacholine Chloride