Asthma, Lung Diseases
Conditions
Keywords
asthma, HEPA, ETS
Brief summary
The purpose of this study is to test the effects of reducing indoor environmental tobacco smoke (ETS) on unscheduled asthma visits, asthma symptoms, airway inflammation, and exposure to tobacco smoke measured using air nicotine dosimeters, serum and hair cotinine.
Detailed description
BACKGROUND: Asthma, a disease characterized by increased airway reactivity and inflammation in response to a variety of stimuli, is emerging as the most prevalent and serious environmental health problem among children in the United States. Numerous studies, both prospective and cross-sectional, suggest that exposure to ETS is one of the predominate risk factors for childhood asthma, but this has not been confirmed in a controlled trial. DESIGN NARRATIVE: The randomized, double-blind prospective trial involving 225 children with doctor-diagnosed asthma who are exposed to environmental tobacco smoke tests the efficacy of reducing such exposure on unscheduled asthma visits and asthma symptoms. The intervention consists of placement of 2 high efficiency air filtration with activated carbon, potassium permanganate and zeolite filter insert to reduce exposure to ETS in the experimental homes and inactive (placebo) units in the control group homes. The following hypotheses are tested. (1.0) Children assigned to the ETS reduction group will have a greater than 20 percent reduction in unscheduled asthma visits during one-year follow-up compared with those in the control group. (1.1) Children assigned to the ETS reduction group will have significant improvements in asthma symptoms compared with children in the control group. (1.2) Children assigned to the ETS reduction group will have greater than 10 percent reduction in ETS exposure and exhaled nitric oxide, a measure of airway inflammation during one year of follow-up compared with the control group.
Interventions
DEVICEHEPA Air Cleaner
Placement of two active HEPA air cleaners in the homes of children
DEVICEPlacebo Filtration Unit
Placement of inactive filtration unit in the homes
Sponsors
National Heart, Lung, and Blood Institute (NHLBI)
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
6 Years to 12 Years
Healthy volunteers
No
Inclusion criteria
* Age 6-12 years at enrollment * Doctor diagnosed asthma by ICD-9 billing codes (from billing records) * Greater than 1 exacerbation(s) in the past year requiring an unscheduled asthma visit * Exposed to the smoke of greater than or equal to 5 cigarettes in and around the house per day * Lived within a 9-county area surrounding the city of Cincinnati
Exclusion criteria
* Already using a HEPA air cleaner * Lacked electricity * Had a coexisting medical problem * Family planned to move in the next year
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Unscheduled asthma visits | Measured at 12 months |
Secondary
| Measure | Time frame |
|---|---|
| Asthma symptoms | Measured at 12 months |
| Exhaled nitric oxide | Measured at 12 months |
| Tobacco smoke exposure, measured using air nicotine dosimeters, serum cotinine and hair cotinine | Measured at 12 months |
Outcome results
None listed