Asthma Placebo Effects
Conditions
Brief summary
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.
Interventions
Sponsors
National Center for Complementary and Integrative Health (NCCIH)
Brigham and Women's Hospital
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 80 Years
Healthy volunteers
No
Inclusion criteria
* uncontrolled asthma
Exclusion criteria
* no bronchodilator response
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in FEV1 | 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. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Asthma Symptoms | 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. |
Countries
United States
Participant flow
Pre-assignment details
79 patients completed questionnaires, 46 patients had reversibility and were randomized, and 39 completed the whole trial. The data was solely based on the 39 subjects who completed the entire trial.
Participants by arm
| Arm | Count |
|---|---|
| Overall Study | 46 |
| Total | 46 |
Baseline characteristics
| Characteristic | Overall Study |
|---|---|
| Age, Continuous | 41.5 years STANDARD_DEVIATION 17 |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants |
| Race (NIH/OMB) Black or African American | 11 Participants |
| Race (NIH/OMB) More than one race | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 7 Participants |
| Race (NIH/OMB) White | 28 Participants |
| Sex: Female, Male Female | 37 Participants |
| Sex: Female, Male Male | 9 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk | EG003 affected / at risk |
|---|---|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — | — / — | — / — |
| other Total, other adverse events | 0 / 39 | 0 / 39 | 0 / 39 | 0 / 39 |
| serious Total, serious adverse events | 0 / 39 | 0 / 39 | 0 / 39 | 0 / 39 |
Outcome results
Primary
Change in FEV1
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.
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.
Population: Each patient went through each treatment arm (albuterol, placebo inhaler, placebo acupuncture, and no-intervention) once in block 1, then again in block 2, and again in block 3, for a total of 12 interventions of the course of the study.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Albuterol Inhaler | Change in FEV1 | 20.1 percentage change in FEV1 | Standard Error 1.6 |
| Placebo Inhaler | Change in FEV1 | 7.5 percentage change in FEV1 | Standard Error 1 |
| Placebo Acupuncture | Change in FEV1 | 7.3 percentage change in FEV1 | Standard Error 0.8 |
| No-intervention Control | Change in FEV1 | 7.1 percentage change in FEV1 | Standard Error 0.8 |
Secondary
Asthma Symptoms
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.
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.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Albuterol Inhaler | Asthma Symptoms | 50 percent change in symptoms | Standard Error 3.75 |
| Placebo Inhaler | Asthma Symptoms | 45 percent change in symptoms | Standard Error 3.75 |
| Placebo Acupuncture | Asthma Symptoms | 46 percent change in symptoms | Standard Error 3.75 |
| No-intervention Control | Asthma Symptoms | 21 percent change in symptoms | Standard Error 3.45 |