Volume 119, Issue 5, Pages 1306-1315 (May 2001) A Placebo-Controlled Clinical Trial of Regular Monotherapy With Short-Acting and Long- Acting β2-Agonists in Allergic Asthmatic Patients  Cloosterman Sonja G.M. , MSc, PhD, Bijl-Hofland Ingrid D. , MSc, PhD, van Herwaarden Cees L.A. , MD, PhD, Akkermans Reinier P. , Sc, van den Elshout Frank J.J. , MD, PhD, Folgering Hans T.M. , MD, PhD, van Schayck Constant P. , MSc, PhD  CHEST  Volume 119, Issue 5, Pages 1306-1315 (May 2001) DOI: 10.1378/chest.119.5.1306 Copyright © 2001 The American College of Chest Physicians Terms and Conditions

Figure 1 Theoretical model explaining the decrease in lung function observed in some cohorts receiving regular treatment withβ 2-agonists. Regular use of β2-agonists might result in negative effects on clinical parameters. Exposure to allergens might also result in negative effect. When both exposures occur, it might result in an even greater effect than just the sum of the two effects (interactive effect). CHEST 2001 119, 1306-1315DOI: (10.1378/chest.119.5.1306) Copyright © 2001 The American College of Chest Physicians Terms and Conditions

Figure 2 Study scheme. LF = lung function measurements; HDM0, HDM1, HDM2, HDM3 = dust samples. CHEST 2001 119, 1306-1315DOI: (10.1378/chest.119.5.1306) Copyright © 2001 The American College of Chest Physicians Terms and Conditions

Figure 3 Changes compared to baseline in (top, A) BHR (PC20) and (bottom, B) FEV1 percent predicted within each of the three medication groups (mean change ± SEM). p = 0.07 among the three groups for PC20; p = 0.17 among the three groups for FEV1. CHEST 2001 119, 1306-1315DOI: (10.1378/chest.119.5.1306) Copyright © 2001 The American College of Chest Physicians Terms and Conditions