title: Does clinical trial subject selection restrict the ability to generalize use and cost of health services to "real life" subjects?
abstract: OBJECTIVE
  To explore one aspect of the external validity of the randomized controlled trial (RCT), specifically how being selected for inclusion in a trial and having participated has influenced the use and cost of asthma-related health services.
  
  
  METHODS
  Services used by asthmatic users of inhaled corticosteroids (iCSTs) having previously participated in an RCT (TS, n = 46) were compared with individuals who had never participated (NS, n = 51).
  
  
  RESULTS
  TS were more likely to use higher (> or = 400 microg) daily doses of iCSTs than NS (OR, 3.3; 95% Cl, 1.1-8.3) but less likely to visit emergency departments (OR, 0.3; 95% Cl, 0.1-0.7). Total asthma-related costs did not differ significantly.
  
  
  CONCLUSIONS
  Subject differences may impede generalizing from RCTs to real life.
authors.affiliation: Faculty of Pharmacy, University of Montreal, Canada. Wendy.Kennedy@umontreal.ca
authors.forename: Wendy A
authors.initials: WA
authors.lastname: Kennedy
authors.forename: Claudine
authors.initials: C
authors.lastname: Laurier
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Malo
authors.forename: Heberto
authors.initials: H
authors.lastname: Ghezzo
authors.forename: Jocelyne
authors.initials: J
authors.lastname: L'Archevêque
authors.forename: André-Pierre
authors.initials: AP
authors.lastname: Contandriopoulos
mesh_terms: D000305:Adrenal Cortex Hormones / Q000008:administration & dosage / Q000191:economics; D000328:Adult; D000368:Aged; D001249:Asthma / Q000188:drug therapy* / Q000191:economics; D001993:Bronchodilator Agents / Q000008:administration & dosage / Q000191:economics; D002170:Canada; D003362:Cost-Benefit Analysis; D004341:Drug Evaluation / Q000191:economics; D005260:Female; D017048:Health Care Costs; D006296:Health Services / Q000191:economics / Q000706:statistics & numerical data*; D006302:Health Services Research; D006801:Humans; D008297:Male; D008875:Middle Aged; D009330:Nebulizers and Vaporizers; D018579:Patient Selection; D016032:Randomized Controlled Trials as Topic
chemical_list: D000305:Adrenal Cortex Hormones; D001993:Bronchodilator Agents