Active albuterol or placebo, sham acupuncture, or no intervention in asthma.
Author(s): Wechsler ME, Kelley JM, Boyd IO, Dutile S, Marigowda G, Kirsch I, Israel E,
Affiliation(s): Division of Pulmonary and Critical Care Medicine, Brigham and Women's Hospital
and Harvard Medical School, Boston, MA 02115, USA. firstname.lastname@example.org
Publication date & source: 2011, N Engl J Med. , 365(2):119-26
BACKGROUND: In prospective experimental studies in patients with asthma, it is
difficult to determine whether responses to placebo differ from the natural
course of physiological changes that occur without any intervention. We compared
the effects of a bronchodilator, two placebo interventions, and no intervention
on outcomes in patients with asthma.
METHODS: In a double-blind, crossover pilot study, we randomly assigned 46
patients with asthma to active treatment with an albuterol inhaler, a placebo
inhaler, sham acupuncture, or no intervention. Using a block design, we
administered one each of these four interventions in random order during four
sequential visits (3 to 7 days apart); this procedure was repeated in two more
blocks of visits (for a total of 12 visits by each patient). At each visit,
spirometry was performed repeatedly over a period of 2 hours. Maximum forced
expiratory volume in 1 second (FEV(1)) was measured, and patients' self-reported
improvement ratings were recorded.
RESULTS: Among the 39 patients who completed the study, albuterol resulted in a
20% increase in FEV(1), as compared with approximately 7% with each of the other
three interventions (P<0.001). However, patients' reports of improvement after
the intervention did not differ significantly for the albuterol inhaler (50%
improvement), placebo inhaler (45%), or sham acupuncture (46%), but the
subjective improvement with all three of these interventions was significantly
greater than that with the no-intervention control (21%) (P<0.001).
CONCLUSIONS: Although albuterol, but not the two placebo interventions, improved
FEV(1) in these patients with asthma, albuterol provided no incremental benefit
with respect to the self-reported outcomes. Placebo effects can be clinically
meaningful and can rival the effects of active medication in patients with
asthma. However, from a clinical-management and research-design perspective,
patient self-reports can be unreliable. An assessment of untreated responses in
asthma may be essential in evaluating patient-reported outcomes. (Funded by the
National Center for Complementary and Alternative Medicine.).