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Randomized Trial to Reduce Environmental Tobacco Smoke in Children With Asthma

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ClinicalTrials.gov Identifier: NCT00006565
Recruitment Status : Completed
First Posted : December 1, 2000
Last Update Posted : February 18, 2016
Information provided by:

Study Description
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.

Condition or disease Intervention/treatment Phase
Asthma Lung Diseases Device: HEPA Air Cleaner Device: Placebo Filtration Unit Phase 3

Detailed Description:


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.


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 Design

Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 225 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Prevention
Official Title: Randomized Trial to Reduce Environmental Tobacco Smoke in Children With Asthma
Study Start Date : September 2000
Primary Completion Date : March 2003
Study Completion Date : April 2004

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Asthma Smoking
U.S. FDA Resources

Arms and Interventions

Arm Intervention/treatment
Experimental: 1
HEPA Air Cleaners
Device: HEPA Air Cleaner
Placement of two active HEPA air cleaners in the homes of children
Other Name: Austin Healthmate HEPA air cleaner
Placebo Comparator: 2
Inactive (placebo) filtration unit
Device: Placebo Filtration Unit
Placement of inactive filtration unit in the homes

Outcome Measures

Primary Outcome Measures :
  1. Unscheduled asthma visits [ Time Frame: Measured at 12 months ]

Secondary Outcome Measures :
  1. Asthma symptoms [ Time Frame: Measured at 12 months ]
  2. Exhaled nitric oxide [ Time Frame: Measured at 12 months ]
  3. Tobacco smoke exposure, measured using air nicotine dosimeters, serum cotinine and hair cotinine [ Time Frame: Measured at 12 months ]

Eligibility Criteria

Information from the National Library of Medicine

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Ages Eligible for Study:   6 Years to 12 Years   (Child)
Sexes Eligible for Study:   All
Accepts 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
Contacts and Locations

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00006565

Sponsors and Collaborators
National Heart, Lung, and Blood Institute (NHLBI)
Principal Investigator: Bruce P Lanphear, MD, MPH Simon Fraser University
More Information

Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: Bruce P. Lanphear, MD, MPH, Simon Fraser University
ClinicalTrials.gov Identifier: NCT00006565     History of Changes
Other Study ID Numbers: 136
R01HL065731 ( U.S. NIH Grant/Contract )
First Posted: December 1, 2000    Key Record Dates
Last Update Posted: February 18, 2016
Last Verified: October 2008

Keywords provided by National Heart, Lung, and Blood Institute (NHLBI):

Additional relevant MeSH terms:
Lung Diseases
Bronchial Diseases
Respiratory Tract Diseases
Lung Diseases, Obstructive
Respiratory Hypersensitivity
Hypersensitivity, Immediate
Immune System Diseases