Probability of asthma based on methacholine challenge.
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.
Palmeiro
E M
EM
Allergic Disease Center, Creighton University, Omaha.
Hopp
R J
RJ
Biven
R E
RE
Bewtra
A K
AK
Nair
N N
NN
Townley
R G
RG
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
D016210:Methacholine Chloride