Characterization of Placebo Responses in Stable Asthma
The investigators hypothesize that different placebos will have different effects on subjective and objective asthma outcomes compared with actual therapy and natural history. .
Subjects with asthma are randomly treated with placebo inhaler, placebo acupuncture, albuterol inhaler, or "no treatment" in random order, on three different occasions each. At each of the 12 visits, spirometry is performed repeatedly over 2 hours. Maximum FEV1 achieved and an 11-point, self-reported scale of improvement are examined.
Asthma Placebo Effects
Drug: placebo inhaler
Procedure: placebo acupuncture
|Study Design:||Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Participant, Care Provider, Investigator, Outcomes Assessor
Primary Purpose: Treatment
|Official Title:||Characterization of Placebo Responses in Stable Asthma|
- Change in FEV1 [ Time Frame: FEV1 was assessed every 20 minutes for 2 hours at each visit. There were 4 visits in each block each visit separated by 3-7 days. There were three blocks each block separated by 3-7 days. ]The baseline FEV1 (before treatment) was subtracted from the maximum FEV1 recorded during the 2 h period following treatment. This difference value was then converted into percent improvement by dividing by baseline FEV1 and multiplying by 100. Each treatment was given 3 times to each patient, so we averaged the 3 values to yield the mean percent change in FEV1 for each condition.
- Asthma Symptoms [ Time Frame: Assesed over 2 hours during each visit. There were 4 visits in each block each visit separated by 3-7 days. There were three blocks each block separated by 3-7 days. ]Subjective change in asthma symptoms on a visual-analogue scale with scores ranging from 0 (no positive change) to 10 (complete positive change). These subjective responses were then converted to percent change during the 2 hours by multiplying each score by 10. Each of these individual subject scores were then averaged to produce an average percent change in symptoms.
|Study Start Date:||January 2005|
|Study Completion Date:||January 2009|
|Primary Completion Date:||January 2009 (Final data collection date for primary outcome measure)|
Active Comparator: albuterol inhaler
Placebo Comparator: placebo inhaler
|Drug: placebo inhaler|
Placebo Comparator: placebo acupuncture
|Procedure: placebo acupuncture|
Please refer to this study by its ClinicalTrials.gov identifier: NCT01143688
|United States, Massachusetts|
|Brigham & women's Hospital|
|Boston, Massachusetts, United States, 02115|
|Principal Investigator:||Michael Wechsler, MD||Brigham and Women's Hospital|