AsthmaCAPSNCT02258893
Indoor Air Pollution and Children With Asthma: An Intervention Trial
A study testing NO2 Scrubber and HEPA filter in people with Asthma, run by Yale University at 1 site in United States.
Trial summary
The purpose of this study is to determine whether reducing indoor exposure to NO2 and particles improves respiratory health in children with asthma. Read more about this study
- Who is it for?
- Ages 5 to 11 years
- Conditions the study is for
- Asthma
- What is being tested?
- NO2 Scrubber and HEPA filter
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 116 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Jan 2016to 31 Aug 2019
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 5 to 11 years
- All sexes
- No healthy volunteers
- Child
Who may be able to join
- 5-11 years of age, enrolled in grades K-5 and living in the recruitment area (CT, MA)
- [The screening questionnaire will determine asthma symptoms in the past 12 months (wheeze, persistent cough, shortness of breath, chest tightness); and asthma medication use in the past 12 months (short-acting β2-agonists, long-acting β2-agonists, inhaled steroids, oral steroids, theophylline, cromones, and/or leukotriene inhibitors). Based on symptoms and medication, asthma severity will be categorized with a score adapted from the Global Initiative for Asthma guidelines (1=mild transient, 2=mild persistent, 3=moderate, 4=severe). Only children in categories 2 (mild persistent, 3 (moderate) or 4 (severe) will be eligible.]
- For potential subjects satisfying these inclusion criteria, a passive NO2 monitor will be sent to the home for placement in the main living space for one week. Families will be called after one week and instructed to cap and return the NO2 monitor in a pre-paid mailer. Families of children living in homes where the one-week integrated average NO2 concentration is ≥ 15 ppb will be invited to participate. We will permit the enrollment of more than one eligible child per family.
Who cannot join
- Using steroid medication for a condition other than asthma
- Chronic respiratory condition other than asthma
- Intention to move or relocate within 6 months
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Indoor Nitrogen Dioxide Exposure and Children With Asthma: An Intervention Trial
The purpose of this study is to determine whether reducing indoor exposure to NO2 and particles improves respiratory health in children with asthma.
Read the detailed description
We have designed a randomized, double-blind, triple cross-over intervention study to examine the efficacy of indoor NO2 reduction on reducing asthma severity. Since particles and NO2 are both byproducts of combustion and associated with gas stove use, the intervention protocol includes a condition using a filter designed to remove particles also implicated in asthma exacerbations (e.g., coarse, fine and ultrafine particles including airborne mold spores and allergens) while leaving NO2 virtually untouched. Primary and secondary aims of the trial include, respectively, determining whether reducing exposure to NO2 and particles compared to a "control" (non-filtered) condition results in a clinically significant reduction in asthma severity measured by a difference in days of symptoms between intervention arms.
Families with asthmatic children age 5-11 will be recruited from selected communities using a: (1) flyers distributed in elementary schools, (2) postcards send to families from purchased mailing lists, (3) posters placed in community buildings (libraries, clinics, etc.), (4) online (Facebook, Craigslist), and (5) letter mailed to families targeted through Yale Joint Data Analytics Team (JDAT). Volunteers will be screened for preliminary eligibility based on household characteristics and active asthmatic status. Potentially eligible families will have homes with a gas cooking stove and seven rooms or fewer. Potentially eligible children will be aged 5-11; have asthma symptoms and/or medication use consistent with severity score categories 2 (mild persistent), 3 (moderate), or 4 (severe) during the previous 12 months; and reside at least 5 days and nights every week in the eligible home.
Households meeting these preliminary criteria will be asked to participate in passive NO2 sampling. A single Palmes tube will be sent to the home for placement in the main living space for one week. Families will be called after one week and instructed to cap and return the NO2 monitor in a pre-paid mailer. Families of children living in homes where the one-week integrated average NO2 concentration is ≥ 15 ppb will be invited to participate. We will permit enrollment of more than one eligible child per family. Participating families will be randomized into one of 6 treatment sequences each requiring 3 periods of 4-weeks preceded by a 1-week washout period. Randomization will be blocked so that for every 18 subjects randomized there will be 3 in each sequence. Randomization will be conducted blindly by the data management department such that each scheduled initial interview/air cleaner installation is assigned a treatment sequence (referring to machines and filters already on site). Minimization techniques will be used to balance the randomized allocation as necessary. Total subject participation time up to 18 weeks.
- Conditions
- Asthma
- Being tested
- NO2 Scrubber, HEPA filter, Control
- Keywords
- Nitrogen Dioxide, Parts per billion
- Medical subject headings
- Asthma
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
NO2 ScrubberOther
an NO2 scrubber that removes NO2 and particles
HEPA filterOther
a HEPA filter that removes 95% of suspended particles ≥ 0.003 μm in size (but does not remove NO2)
ControlOther
a "control" filter designed to be the same size and weight as the other two filters, but filters neither NO2 nor particles
| Study group | Role | What they receive |
|---|---|---|
| NO2 Scrubber, then HEPA filter, then Control | Experimental | Participants will have 3 periods of 4 weeks with each filter with a 1 week washout between phases in the order of NO2 Scrubber, then HEPA filter, then Control. Receives: Other: NO2 Scrubber; Other: HEPA filter; Other: Control |
| NO2 Scrubber, then Control, then HEPA filter | Experimental | Participants will have 3 periods of 4 weeks with each filter with a 1 week washout between phases in the order of NO2 Scrubber, then Control, then HEPA filter Receives: Other: NO2 Scrubber; Other: HEPA filter; Other: Control |
| HEPA filter, then NO2 scrubber, then Control | Experimental | Participants will have 3 periods of 4 weeks with each filter with a 1 week washout between phases in the order of HEPA filter, then NO2 scrubber, then Control Receives: Other: NO2 Scrubber; Other: HEPA filter; Other: Control |
| HEPA filter, then Control, then NO2 scrubber | Experimental | Participants will have 3 periods of 4 weeks with each filter with a 1 week washout between phases in the order of HEPA filter, then Control, then NO2 scrubber Receives: Other: NO2 Scrubber; Other: HEPA filter; Other: Control |
| Control, then HEPA filter, then NO2 scrubber | Experimental | Participants will have 3 periods of 4 weeks with each filter with a 1 week washout between phases in the order of Control, then HEPA filter, then NO2 scrubber Receives: Other: NO2 Scrubber; Other: HEPA filter; Other: Control |
| Control, then NO2 scrubber, then HEPA filter | Experimental | Participants will have 3 periods of 4 weeks with each filter with a 1 week washout between phases in the order of Control, then NO2 scrubber, then HEPA filter Receives: Other: NO2 Scrubber; Other: HEPA filter; Other: Control |
What is being measured
The primary outcome is the main question the study is designed to answer.
Days with symptoms
The maximum of the following variables reported over the 2-week recall period: (1) number of days with wheezing, chest tightness, or persistent cough; (2) number of nights of sleep disturbance; (3) number of days when activities were affected.
Measured: Final 14 days of intervention
Secondary outcomes (9)
Days of wheeze
As measured by self report
Measured: Post 4 week intervention
Night symptoms
As measured by self report
Measured: Post 4 week intervention
Rescue medication use
As measured by self report
Measured: Post 4 week intervention
Symptom Score
The score is adapted from the Global Initiative for Asthma Guidelines which incorporates type and frequency of symptoms and medications. The symptom score portion, is a 5-level score calculated based on symptoms during the last 4-weeks of the intervention.
Measured: Last 4 weeks of intervention
Amount of Restricted Activity
Activity Restrictions as measured by self report
Measured: Post 4 week intervention
Number of Missed days of school
As measured by self report
Measured: Post 4 week intervention
Number of Hospitalizations
As measured by self report
Measured: Post 4 week intervention
Number of Emergency Room Visits
As measured by self report
Measured: Post 4 week intervention
Number of Doctors Visits
As measured by self report
Measured: Post 4 week intervention
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted8 Oct 2014 (estimated)
- Study start1 Jan 2016
- Primary completion31 Aug 2019
- Study completion31 Aug 2019
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for AsthmaStudies of the same condition, open and under way.
- More trials run by Yale UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 116 participants (actual)
Sponsor and investigators
- Lead sponsor
- Yale University
- Sponsor type
- University, hospital or other
- Collaborators
- Harvard University, National Institute of Environmental Health Sciences (NIEHS)
- Responsible party
- Sponsor
- Investigators
- Brian Leaderer, PhD, MPH, Principal investigator, Yale UniversityMichael Bracken, PhD MPH FACE, Principal investigator, Yale UniversityTheodore Holford, PhD, Principal investigator, Yale UniversityJanneane Gent, PhD, Principal investigator, Yale University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02258893
- Sponsor's protocol ID
- 1308012531
- Other IDs
- 5R01ES023505-05
- Acronym
- CAPS
- Status last verified
- Nov 2020
- First submitted
- 2 Oct 2014
- Last updated
- 23 Nov 2020
- Results posted
- No
- Data monitoring committee
- Yes
Publications
Gent JF, Holford TR, Bracken MB, Plano JM, McKay LA, Sorrentino KM, Koutrakis P, Leaderer BP. Childhood asthma and household exposures to nitrogen dioxide and fine particles: a triple-crossover randomized intervention trial. J Asthma. 2023 Apr;60(4):744-753. doi: 10.1080/02770903.2022.2093219. Epub 2022 Jul 7.
PubMed 35796019
Study at a glance
From the registry record, last updated by the sponsor on 23 Nov 2020. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Indoor Nitrogen Dioxide Exposure and Children With Asthma: An Intervention Trial
- ClinicalTrials.gov ID
- NCT02258893
- Acronym / sponsor ID
- CAPS / 1308012531
- Conditions
- Asthma
- Keywords
- Nitrogen Dioxide, Parts per billion
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 116 participants (actual)
- Lead sponsor
- Yale UniversityUniversity, hospital or other
- Collaborators
- Harvard University, National Institute of Environmental Health Sciences (NIEHS)
- Study start
- 1 Jan 2016 (actual)
- Primary completion
- 31 Aug 2019 (actual)
- Study completion
- 31 Aug 2019 (actual)
- First posted
- 8 Oct 2014 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this study is to determine whether reducing indoor exposure to NO2 and particles improves respiratory health in children with asthma.
Detailed description
We have designed a randomized, double-blind, triple cross-over intervention study to examine the efficacy of indoor NO2 reduction on reducing asthma severity. Since particles and NO2 are both byproducts of combustion and associated with gas stove use, the intervention protocol includes a condition using a filter designed to remove particles also implicated in asthma exacerbations (e.g., coarse, fine and ultrafine particles including airborne mold spores and allergens) while leaving NO2 virtually untouched. Primary and secondary aims of the trial include, respectively, determining whether reducing exposure to NO2 and particles compared to a "control" (non-filtered) condition results in a clinically significant reduction in asthma severity measured by a difference in days of symptoms between intervention arms.
Families with asthmatic children age 5-11 will be recruited from selected communities using a: (1) flyers distributed in elementary schools, (2) postcards send to families from purchased mailing lists, (3) posters placed in community buildings (libraries, clinics, etc.), (4) online (Facebook, Craigslist), and (5) letter mailed to families targeted through Yale Joint Data Analytics Team (JDAT). Volunteers will be screened for preliminary eligibility based on household characteristics and active asthmatic status. Potentially eligible families will have homes with a gas cooking stove and seven rooms or fewer. Potentially eligible children will be aged 5-11; have asthma symptoms and/or medication use consistent with severity score categories 2 (mild persistent), 3 (moderate), or 4 (severe) during the previous 12 months; and reside at least 5 days and nights every week in the eligible home.
Households meeting these preliminary criteria will be asked to participate in passive NO2 sampling. A single Palmes tube will be sent to the home for placement in the main living space for one week. Families will be called after one week and instructed to cap and return the NO2 monitor in a pre-paid mailer. Families of children living in homes where the one-week integrated average NO2 concentration is ≥ 15 ppb will be invited to participate. We will permit enrollment of more than one eligible child per family. Participating families will be randomized into one of 6 treatment sequences each requiring 3 periods of 4-weeks preceded by a 1-week washout period. Randomization will be blocked so that for every 18 subjects randomized there will be 3 in each sequence. Randomization will be conducted blindly by the data management department such that each scheduled initial interview/air cleaner installation is assigned a treatment sequence (referring to machines and filters already on site). Minimization techniques will be used to balance the randomized allocation as necessary. Total subject participation time up to 18 weeks.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind (participant, investigator)
- Number of arms
- 6
| Arm | Type | Receives |
|---|---|---|
| NO2 Scrubber, then HEPA filter, then Control | Experimental | Other: NO2 Scrubber, Other: HEPA filter, Other: ControlParticipants will have 3 periods of 4 weeks with each filter with a 1 week washout between phases in the order of NO2 Scrubber, then HEPA filter, then Control. |
| NO2 Scrubber, then Control, then HEPA filter | Experimental | Other: NO2 Scrubber, Other: HEPA filter, Other: ControlParticipants will have 3 periods of 4 weeks with each filter with a 1 week washout between phases in the order of NO2 Scrubber, then Control, then HEPA filter |
| HEPA filter, then NO2 scrubber, then Control | Experimental | Other: NO2 Scrubber, Other: HEPA filter, Other: ControlParticipants will have 3 periods of 4 weeks with each filter with a 1 week washout between phases in the order of HEPA filter, then NO2 scrubber, then Control |
| HEPA filter, then Control, then NO2 scrubber | Experimental | Other: NO2 Scrubber, Other: HEPA filter, Other: ControlParticipants will have 3 periods of 4 weeks with each filter with a 1 week washout between phases in the order of HEPA filter, then Control, then NO2 scrubber |
| Control, then HEPA filter, then NO2 scrubber | Experimental | Other: NO2 Scrubber, Other: HEPA filter, Other: ControlParticipants will have 3 periods of 4 weeks with each filter with a 1 week washout between phases in the order of Control, then HEPA filter, then NO2 scrubber |
| Control, then NO2 scrubber, then HEPA filter | Experimental | Other: NO2 Scrubber, Other: HEPA filter, Other: ControlParticipants will have 3 periods of 4 weeks with each filter with a 1 week washout between phases in the order of Control, then NO2 scrubber, then HEPA filter |
Who may qualify
- Ages
- 5 to 11 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child
Key inclusion criteria (3 listed)
- 5-11 years of age, enrolled in grades K-5 and living in the recruitment area (CT, MA)
- [The screening questionnaire will determine asthma symptoms in the past 12 months (wheeze, persistent cough, shortness of breath, chest tightness); and asthma medication use in the past 12 months (short-acting β2-agonists, long-acting β2-agonists, inhaled steroids, oral steroids, theophylline, cromones, and/or leukotriene inhibitors). Based on symptoms and medication, asthma severity will be categorized with a score adapted from the Global Initiative for Asthma guidelines (1=mild transient, 2=mild persistent, 3=moderate, 4=severe). Only children in categories 2 (mild persistent, 3 (moderate) or 4 (severe) will be eligible.]
- For potential subjects satisfying these inclusion criteria, a passive NO2 monitor will be sent to the home for placement in the main living space for one week. Families will be called after one week and instructed to cap and return the NO2 monitor in a pre-paid mailer. Families of children living in homes where the one-week integrated average NO2 concentration is ≥ 15 ppb will be invited to participate. We will permit the enrollment of more than one eligible child per family.
Key exclusion criteria (3 listed)
- Using steroid medication for a condition other than asthma
- Chronic respiratory condition other than asthma
- Intention to move or relocate within 6 months
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| NO2 Scrubberan NO2 scrubber that removes NO2 and particles | Other | Control, then HEPA filter, then NO2 scrubber, Control, then NO2 scrubber, then HEPA filter, HEPA filter, then Control, then NO2 scrubber, HEPA filter, then NO2 scrubber, then Control, NO2 Scrubber, then Control, then HEPA filter, NO2 Scrubber, then HEPA filter, then Control |
| HEPA filtera HEPA filter that removes 95% of suspended particles ≥ 0.003 μm in size (but does not remove NO2) | Other | Control, then HEPA filter, then NO2 scrubber, Control, then NO2 scrubber, then HEPA filter, HEPA filter, then Control, then NO2 scrubber, HEPA filter, then NO2 scrubber, then Control, NO2 Scrubber, then Control, then HEPA filter, NO2 Scrubber, then HEPA filter, then Control |
| Controla "control" filter designed to be the same size and weight as the other two filters, but filters neither NO2 nor particles | Other | Control, then HEPA filter, then NO2 scrubber, Control, then NO2 scrubber, then HEPA filter, HEPA filter, then Control, then NO2 scrubber, HEPA filter, then NO2 scrubber, then Control, NO2 Scrubber, then Control, then HEPA filter, NO2 Scrubber, then HEPA filter, then Control |
Primary outcome
Days with symptoms
Time frame: Final 14 days of intervention
The maximum of the following variables reported over the 2-week recall period: (1) number of days with wheezing, chest tightness, or persistent cough; (2) number of nights of sleep disturbance; (3) number of days when activities were affected.
9 secondary outcomes
Days of wheeze
Time frame: Post 4 week intervention
Night symptoms
Time frame: Post 4 week intervention
Rescue medication use
Time frame: Post 4 week intervention
Symptom Score
Time frame: Last 4 weeks of intervention
Amount of Restricted Activity
Time frame: Post 4 week intervention
Number of Missed days of school
Time frame: Post 4 week intervention
Number of Hospitalizations
Time frame: Post 4 week intervention
Number of Emergency Room Visits
Time frame: Post 4 week intervention
Number of Doctors Visits
Time frame: Post 4 week intervention
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 23 Nov 2020.
- Derived from this study: PubMed 35796019Gent JF, Holford TR, Bracken MB, Plano JM, McKay LA, Sorrentino KM, Koutrakis P, Leaderer BP. Childhood asthma and household exposures to nitrogen dioxide and fine particles: a triple-crossover randomized intervention trial. J Asthma. 2023 Apr;60(4):744-753. doi: 10.1080/02770903.2022.2093219. Epub 2022 Jul 7.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Brian Leaderer, PhD, MPH principal investigator
Yale University
Michael Bracken, PhD MPH FACE principal investigator
Yale University
Theodore Holford, PhD principal investigator
Yale University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing NO2 Scrubber and HEPA filter in people with Asthma, run by Yale University at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 23 Nov 2020. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Days with symptoms (time frame: Final 14 days of intervention). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT02258893, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 23 Nov 2020; AzTrials last refreshed its copy on 7 Nov 2026.