Performance Characteristics of Spirometry With Negative Bronchodilator Response and Methacholine Challenge Testing and Implications for Asthma Diagnosis

Autor: Janannii Selvanathan, Shawn D. Aaron, Jenna R. Sykes, Katherine L. Vandemheen, J. Mark FitzGerald, Martha Ainslie, Catherine Lemière, Stephen K. Field, R. Andrew McIvor, Paul Hernandez, Irvin Mayers, Sunita Mulpuru, Gonzalo G. Alvarez, Smita Pakhale, Ranjeeta Mallick, Louis-Philippe Boulet, Samir Gupta, Shawn Aaron, James Martin, Peter Paré, James Hogg, Christopher Carlsten, Jonathon Leipsic, Don Sin, Wan Tan, Jordan Guenette, Mark FitzGerald, Harvey Coxson, Mohsen Sadatsafavi, Carlo Marra, John Mayo, David Proud, Richard Leigh, Anita Kozyrskyj, Jacqueline Quail, Andrew Halayko, Marni Brownell, Grace Parraga, Parameswaran Nair, Martin Stampfli, Paul O’Byrne, Noe Zamel, Felix Ratjen, Dina Brooks, Andrea Gershon, Teresa To, Wendy Ungar, Diane Lougheed, Denis O’Donnell, Bernard Thebaud, Dean Fergusson, Ian Graham, Jeremy Grimshaw, Katherine Vandemheen, Anne Van Dam, Andrea Benedetti, Jean Bourbeau, Larry Lands, Dennis Jensen, Jennifer Landry, Lucie Blais, Francine Ducharme, Anne-Monique Nuyt, Yohan Bossé, Francois Maltais, Marieve Doucet
Rok vydání: 2020
Předmět:
Zdroj: Chest. 158:479-490
ISSN: 0012-3692
DOI: 10.1016/j.chest.2020.03.052
Popis: Background In patients with a history suggestive of asthma, diagnosis is usually confirmed by spirometry with bronchodilator response (BDR) or confirmatory methacholine challenge testing (MCT). Research Question We examined the proportion of participants with negative BDR testing who had a positive MCT (and its predictors) result and characteristics of MCT, including effects of controller medication tapering and temporal variability (and predictors of MCT result change), and concordance between MCT and pulmonologist asthma diagnosis. Study Design and Methods Adults with self-reported physician-diagnosed asthma were recruited by random-digit dialing across Canada. Subjects performed spirometry with BDR testing and returned for MCT if testing was nondiagnostic for asthma. Subjects on controllers underwent medication tapering with serial MCTs over 3 to 6 weeks. Subjects with a negative MCT (the provocative concentration of methacholine that results in a 20% drop in FEV1 [PC20] > 8 mg/mL) off medications were examined by a pulmonologist and had serial MCTs after 6 and 12 months. Results Of 500 subjects (50.5 ± 16.6 years old, 68.0% female) with a negative BDR test for asthma, 215 (43.0%) had a positive MCT. Subjects with prebronchodilator airflow limitation were more likely to have a positive MCT (OR, 1.90; 95% CI, 1.17-3.04). MCT converted from negative to positive, with medication tapering in 18 of 94 (19.1%) participants, and spontaneously over time in 25 of 165 (15.2%) participants. Of 231 subjects with negative MCT, 28 (12.1%) subsequently received an asthma diagnosis from a pulmonologist. Interpretation In subjects with a self-reported physician diagnosis of asthma, absence of bronchodilator reversibility had a negative predictive value of only 57% to exclude asthma. A finding of spirometric airflow limitation significantly increased chances of asthma. MCT results varied with medication taper and over time, and pulmonologists were sometimes prepared to give a clinical diagnosis of asthma despite negative MCT. Correspondingly, in patients for whom a high clinical suspicion of asthma exists, repeat testing appears to be warranted.
Databáze: OpenAIRE
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