Asthma and Indoor-air: Reducing Exposures

NCT01869543 | Completed

• 2 other identifiers: 34612311-324
• Study Type: interventional
• Target: 219
• Locations: 1 country
• Sites: 1

Brief Summary

Two hundred moderate to severely asthmatic children (6-12 years) will be enrolled in a study to look at the effectiveness of high efficiency filtration of indoor air in homes on reducing asthma symptoms. One intervention group will have high efficiency filters or filtration systems installed in their central heating and air conditioning (HVAC) system. The second intervention group will have high efficiency portable air cleaners placed in the child's bedroom and in the main living area. Each participant will receive true air filtration for a year and a placebo for a year. During the placebo period a sham filter will be used that removes very little of the particles. Measures of health effects will include days of symptoms, unplanned utilization of the healthcare system for asthma-related illness, short-term medication use, peak exhaled flow, spirometry, and exhaled nitric oxide (eNO).

Conditions

Asthma

Outcome Measures

Primary Outcomes (1)

• Days with asthma symptoms

  The maximum number of days with symptoms, from a two-week recall period, will be determined every three months. The maximum number of days with symptoms will be defined as the largest value among the following three variables: (i) number of days with wheezing, tightness in the chest, or cough because of asthma, (ii) number of days that the child had to slow down or stop his/her play or activities because of asthma, wheezing or tightness in the chest, or cough, or (iii) number of nights that the child woke up because of asthma, wheezing or tightness in the chest, or cough. The seasonally adjusted mean difference in the number of symptom days between the true and sham filtration periods will be estimated using generalized linear mixed-effects regression models.

  Measured at 3, 6, 9, 12, 15, 18, 21, and 24 months

Secondary Outcomes (13)

• Forced expiratory volume at one second, percent predicted (FEV1 % predicted)

  Measured at 12 months and 24 months

• Forced vital capacity, percent predicted (FVC % predicted)

  Measured at 12 months and 24 months

• Peak Expiratory Flow Rate (PEFR)

  Measured at 3, 6, 9, 12, 15, 18, 21, and 24 months

• Exhaled NO

  Measure at 6, 12, 18, and 24 months

• Days of missing school due to asthma

  Measured at 3, 6, 9, 12, 15, 18, 21, and 24 months

Study Arms (4)

Stand Alone Air Cleaner-True/Sham

EXPERIMENTAL

The participant will have stand alone air cleaners placed in their home. They will have true filtration followed by sham filtration.

Other: Stand Alone Air Cleaner

Stand Alone Air Cleaner-Sham/True

EXPERIMENTAL

Participants will have stand alone air cleaners placed in their homes. They will begin with sham filtration.

Other: Stand Alone Air Cleaner

HVAC modification-True/Sham

EXPERIMENTAL

Participants will have their HVAC system modified to include high efficiency filtration. They will begin true filtration followed by sham filtration.

Other: HVAC Modification

HVAC Modification-Sham/True

EXPERIMENTAL

Participants will have their HVAC system modified to include high efficiency filtration. They will begin sham filtration.

Other: HVAC Modification

Interventions

Stand Alone Air Cleaner OTHER

This is an environmental intervention using a stand alone air cleaner designed to reduce the air pollution levels in the home.

Stand Alone Air Cleaner-Sham/True; Stand Alone Air Cleaner-True/Sham

HVAC Modification OTHER

This is an environmental intervention that modifies the home HVAC system to include high efficiency air filtration designed to reduce the air pollution levels in the home.

HVAC Modification-Sham/True; HVAC modification-True/Sham

Eligibility Criteria

• Age: 6 Years - 12 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17)

You may qualify if:

• years of age
• Living in Fresno, San Bernardino or Riverside Counties.
• Physician diagnosed asthma, as stated by the participant's caregiver.
• In the last six months, the child must have had asthma symptoms at least twice a week for several weeks in a row.

You may not qualify if:

• Children living in homes where more than 2 cigarettes are smoked per week in the home.
• Children that spend 2 or more nights per week in another home.
• Children living in homes that are planning on moving in the next 2 years.
• Children living in homes that keep their windows open most of the time.
• Children living in homes that have existing high efficiency filtration.

Sponsors & Collaborators

• University of California, Davis: lead

Study Sites (1)

University of California, Davis- Department of Public Health Sciences

Davis, California, 95616, United States

Location

MeSH Terms

Conditions

Asthma

Condition Hierarchy (Ancestors)

Bronchial Diseases; Respiratory Tract Diseases; Lung Diseases, Obstructive; Lung Diseases; Respiratory Hypersensitivity; Hypersensitivity, Immediate; Hypersensitivity; Immune System Diseases

Study Officials

• Deborah Bennett, PhD

  University of California, Davis

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, CARE PROVIDER
• Purpose: OTHER
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: April 3, 2013
• First Posted: June 5, 2013
• Study Start: July 1, 2012
• Primary Completion: February 8, 2017
• Study Completion: February 8, 2017
• Last Updated: March 21, 2019

Record last verified: 2019-03

Locations

US (1)