BACKGROUND: Constant-dose allergen inhalation challenges are frequently used to examine the effect of antiasthma drugs on the allergen-induced early and late asthmatic responses. The end-point measurements in such studies are the maximal early and late percent decreases in the forced expiratory volume in 1 second (FEV1). OBJECTIVE: Our purpose was to observe the reproducibility and to determine the sample sizes required for such studies. METHODS: Twenty-eight subjects with allergen-induced early and late responses were studied with two constant-dose allergen challenges separated by 2 to 12 weeks. The early response was measured as the maximum percent decrease in FEV1 during the first 2 hours and the late response as the maximum percent decrease in FEV1 between 3 to 7 hours. RESULTS: The mean +/- SEM early responses were 23.1% +/- 1.0% and 24.7% +/- 2.0%, whereas the mean late responses were 23.3% +/- 2.0% and 24.5% +/- 2.2%. Reproducibility of measurements were such that fewer than eight subjects are required, to show 50% attenuation of either the early or late response (with 90% power). CONCLUSIONS: The method of constant-dose allergen challenge is a sensitive tool for detecting changes in early and late asthmatic responses after the use of antiasthma medication.
BACKGROUND: Constant-dose allergen inhalation challenges are frequently used to examine the effect of antiasthma drugs on the allergen-induced early and late asthmatic responses. The end-point measurements in such studies are the maximal early and late percent decreases in the forced expiratory volume in 1 second (FEV1). OBJECTIVE: Our purpose was to observe the reproducibility and to determine the sample sizes required for such studies. METHODS: Twenty-eight subjects with allergen-induced early and late responses were studied with two constant-dose allergen challenges separated by 2 to 12 weeks. The early response was measured as the maximum percent decrease in FEV1 during the first 2 hours and the late response as the maximum percent decrease in FEV1 between 3 to 7 hours. RESULTS: The mean +/- SEM early responses were 23.1% +/- 1.0% and 24.7% +/- 2.0%, whereas the mean late responses were 23.3% +/- 2.0% and 24.5% +/- 2.2%. Reproducibility of measurements were such that fewer than eight subjects are required, to show 50% attenuation of either the early or late response (with 90% power). CONCLUSIONS: The method of constant-dose allergen challenge is a sensitive tool for detecting changes in early and late asthmatic responses after the use of antiasthma medication.
Authors: William W Busse; Adam Wanner; Kenneth Adams; Herbert Y Reynolds; Mario Castro; Badrul Chowdhury; Monica Kraft; Robert J Levine; Stephen P Peters; Eugene J Sullivan Journal: Am J Respir Crit Care Med Date: 2005-07-14 Impact factor: 21.405
Authors: Gail M Gauvreau; Beth E Davis; Guy Scadding; Louis-Philippe Boulet; Leif Bjermer; Adam Chaker; Donald W Cockcroft; Barbro Dahlén; Wyste Fokkens; Peter Hellings; Nikolaos Lazarinis; Paul M O'Byrne; Ellen Tufvesson; Santiago Quirce; Maurits Van Maaren; Frans H de Jongh; Zuzana Diamant Journal: Eur Respir J Date: 2022-08-25 Impact factor: 33.795