Does clinical trial subject selection restrict the ability to generalize use and cost of health services to "real life" subjects?
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.
Kennedy
Wendy A
WA
Faculty of Pharmacy, University of Montreal, Canada. Wendy.Kennedy@umontreal.ca
Laurier
Claudine
C
Malo
Jean-Luc
JL
Ghezzo
Heberto
H
L'Archevêque
Jocelyne
J
Contandriopoulos
André-Pierre
AP
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
D000305:Adrenal Cortex Hormones; D001993:Bronchodilator Agents