title: Probability of asthma based on methacholine challenge.
abstract: Methacholine inhalation challenge has become an accepted test to determine the presence of airway hyperresponsiveness, a hallmark of asthma. To help physicians interpret the results of a methacholine challenge test in a clinical setting, we analyzed the test data of 1,105 subjects, asthmatics and nonasthmatics. Applying Bayes' theorem, a nomogram was constructed incorporating the prechallenge clinical diagnosis with the response to methacholine to give a posttest probability of the diagnosis of asthma. The resulting curves represent different levels of cumulative breath units at which a methacholine challenge can be considered positive. The results of a methacholine challenge test, in association with a physician's clinical assessment, can be a valuable tool in the diagnosis of asthma in those patients with an atypical history and/or physical examination.
authors.affiliation: Allergic Disease Center, Creighton University, Omaha.
authors.forename: E M
authors.initials: EM
authors.lastname: Palmeiro
authors.forename: R J
authors.initials: RJ
authors.lastname: Hopp
authors.forename: R E
authors.initials: RE
authors.lastname: Biven
authors.forename: A K
authors.initials: AK
authors.lastname: Bewtra
authors.forename: N N
authors.initials: NN
authors.lastname: Nair
authors.forename: R G
authors.initials: RG
authors.lastname: Townley
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001249:Asthma / Q000175:diagnosis* / Q000503:physiopathology; D001985:Bronchial Provocation Tests; D002648:Child; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008297:Male; D016210:Methacholine Chloride; D008875:Middle Aged; D011336:Probability; D012680:Sensitivity and Specificity
chemical_list: D016210:Methacholine Chloride