Document Detail


Baseline predictors of placebo response in exercise-induced bronchoconstriction (EIB): pooled regression analysis >from three studies of montelukast in EIB.
MedLine Citation:
PMID:  20858150     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: Exercise-induced bronchoconstriction (EIB) can be variable in its presentation and severity. Evaluating patterns of placebo response and patient-related factors driving placebo response could facilitate more efficient clinical trials for EIB. METHODS: Data were pooled from three randomized, double-blind, crossover trials evaluating single-dose montelukast 10 mg or placebo in patients (N = 160) 15-45 years of age with EIB, defined as maximum % fall in forced expiratory volume in one second (FEV₁) ≥20% after two screening exercise challenges. Serial exercise challenges were performed at 2, 8.5-12, and 24 h postdose. The authors evaluated the distribution and variability of placebo response. They also evaluated possible drivers of response, analyzing all baseline patient demographic and prerandomization screening visit pulmonary function data as single covariates in a simple univariate regression model for maximum % fall in FEV₁ while on placebo at 2 h postdose. All covariates with p values <.1 were entered into both stepwise forward and backward regression procedures to select the "best" model. RESULTS: Placebo response was variable, and showed a significant non-normal distribution (p < .001). Significant predictors of a greater response to placebo included: higher screening FEV₁ % predicted (p <.001), smaller maximum % fall in FEV₁ in screening (p < .001), shorter time to recovery in screening (p = .007), more asthma-related health care visits in the previous year (p = .004), older age (p = .001), less frequent asthma awakenings in the previous month (p = .003), and less frequent asthma symptoms in the past year (p = .011). CONCLUSION: Predictors of a larger placebo response were generally markers of less severe asthma and/or EIB. This may be related to EIB variability, spontaneous improvement, or the extent of placebo response relative to the outcomes in less severe patients.
Authors:
George Philip; Arlene S Swern; Steven S Smugar; David S Pearlman
Publication Detail:
Type:  Journal Article; Randomized Controlled Trial; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  The Journal of asthma : official journal of the Association for the Care of Asthma     Volume:  47     ISSN:  1532-4303     ISO Abbreviation:  J Asthma     Publication Date:  2010 Oct 
Date Detail:
Created Date:  2010-09-29     Completed Date:  2010-11-04     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8106454     Medline TA:  J Asthma     Country:  England    
Other Details:
Languages:  eng     Pagination:  935-41     Citation Subset:  IM    
Affiliation:
Merck Research Laboratories, North Wales, Pennsylvania 19454, USA. george_philip@merck.com
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MeSH Terms
Descriptor/Qualifier:
Acetates / therapeutic use*
Adolescent
Adult
Anti-Asthmatic Agents / therapeutic use*
Asthma, Exercise-Induced / drug therapy*,  physiopathology
Cross-Over Studies
Double-Blind Method
Female
Forced Expiratory Volume / drug effects
Humans
Male
Middle Aged
Placebo Effect
Quinolines / therapeutic use*
Young Adult
Chemical
Reg. No./Substance:
0/Acetates; 0/Anti-Asthmatic Agents; 0/Quinolines; 158966-92-8/montelukast

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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