Randomized Trial to Reduce Environmental Tobacco Smoke in Children With Asthma

Phase 3

Completed

• Conditions: Lung Diseases; Asthma
• Interventions: Device: HEPA Air Cleaner; Device: Placebo Filtration Unit

• Registration Number: NCT00006565
• Lead Sponsor: National Heart, Lung, and Blood Institute (NHLBI)

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.

Study Timeline

• Study Start: 2000-09
• Study First Submitted QC: 2000-11-30
• Study First Submitted: 2000-12-01
• Study First Posted: 2000-12-01
• Primary Completion: 2003-03
• Study Completion: 2004-04
• Status Verified: 2008-10
• Last Update Submitted: 2016-02-17
• Last Update Posted: 2016-02-18

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 225

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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
1	HEPA Air Cleaner	HEPA Air Cleaners
2	Placebo Filtration Unit	Inactive (placebo) filtration unit

Primary Outcome Measures

Name	Time	Method
Unscheduled asthma visits	Measured at 12 months

Secondary Outcome Measures

Name	Time	Method
Exhaled nitric oxide	Measured at 12 months
Asthma symptoms	Measured at 12 months
Tobacco smoke exposure, measured using air nicotine dosimeters, serum cotinine and hair cotinine	Measured at 12 months