<clinical_study>
  <!-- This xml conforms to an XML Schema at:
    https://clinicaltrials.gov/ct2/html/images/info/public.xsd -->
  <required_header>
    <download_date>ClinicalTrials.gov processed this data on September 20, 2023</download_date>
    <link_text>Link to the current ClinicalTrials.gov record.</link_text>
    <url>https://clinicaltrials.gov/ct2/show/NCT03282864</url>
  </required_header>
  <id_info>
    <org_study_id>[2016] 48</org_study_id>
    <nct_id>NCT03282864</nct_id>
  </id_info>
  <brief_title>The Impact of Air Filtration on Asthmatic Children</brief_title>
  <official_title>The Impact of Air Filtration on Health Indicators of Asthmatic Children</official_title>
  <sponsors>
    <lead_sponsor>
      <agency>Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine</agency>
      <agency_class>Other</agency_class>
    </lead_sponsor>
    <collaborator>
      <agency>Underwriters Laboratory, Inc</agency>
      <agency_class>Other</agency_class>
    </collaborator>
    <collaborator>
      <agency>Duke University</agency>
      <agency_class>Other</agency_class>
    </collaborator>
    <collaborator>
      <agency>Tsinghua University</agency>
      <agency_class>Other</agency_class>
    </collaborator>
    <collaborator>
      <agency>University of Wisconsin, Madison</agency>
      <agency_class>Other</agency_class>
    </collaborator>
  </sponsors>
  <source>Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine</source>
  <oversight_info>
    <has_dmc>No</has_dmc>
    <is_fda_regulated_drug>No</is_fda_regulated_drug>
    <is_fda_regulated_device>No</is_fda_regulated_device>
  </oversight_info>
  <brief_summary>
    <textblock>
      This study uses a crossover study design to examine the impact of a two-week bedroom based&#xD;
      indoor air filtration on the concentration of indoor airborne pollutants, personal exposure&#xD;
      to airborne pollutants and health indicators among asthmatic children living in Shanghai,&#xD;
      China&#xD;
    </textblock>
  </brief_summary>
  <detailed_description>
    <textblock>
      This study recruited asthmatic children aged 5 to 14 who were living in Shanghai, China.&#xD;
      Every study subject had the air in their bedroom processed by an air filtration device (with&#xD;
      a pre-filter, a HEPA filter and an active carbon filter) for two weeks (active comparator&#xD;
      arm), processed by a placebo air filtration device (which did not possess the HEPA filter and&#xD;
      active carbon filters) for two weeks (placebo arm), and underwent a two-week washout period&#xD;
      (no use of air filtration device) between the two intervention periods. The doors and windows&#xD;
      of the bedroom were instructed to be kept closed during the intervention periods. The&#xD;
      sequence of being in the active comparator arm and the placebo arm was randomized for each&#xD;
      subject. The subject, their guardian and researchers who have direct interaction with the&#xD;
      study subjects do not know this sequence until after the end of the study.&#xD;
&#xD;
      The study protocol was approved by IRB at Shanghai First People's Hospital, Duke University&#xD;
      and University of Wisconsin at Madison. A sample size of 40 was calculated using fractional&#xD;
      exhaled nitric oxide (FeNO) as the primary outcome where statistical significance was set at&#xD;
      0.05, power at 90%, and between-subject variance and covariance were estimated from existing&#xD;
      literature. Four additional subjects were added to the estimated sample size of 40 to account&#xD;
      for potential dropouts. Subjects were recruited from patients who attended the outpatient&#xD;
      clinic of the Pediatrics Department of Shanghai First People's Hospital (south section) by&#xD;
      Dr. Zhen Li and Dr. Junfeng Zhang's team. Assent was obtained from all study subjects and&#xD;
      written informed consent was obtained from their guardians.&#xD;
&#xD;
      During the study, Dr. Michael Bergin's team and Dr. Yinping Zhang's team installed the air&#xD;
      filtration devices in the subject's bedroom and measured the indoor concentration, outdoor&#xD;
      concentration and personal exposure to airborne pollutants including PM2.5, ozone and&#xD;
      volatile organic compounds. Dr. James Schauer's team analyzed the physical, chemical and&#xD;
      bioactivity of the airborne particles collected and had no direct contact with the study&#xD;
      subjects.&#xD;
&#xD;
      Each subject attended 5 clinical visits at the Shanghai First People's Hospital (South&#xD;
      Section) accompanied by their guardian where clinical assessment (of lung function,&#xD;
      fractional exhaled nitric oxide, asthma symptom blood draw) was performed by Drs. Zhen Li and&#xD;
      Feng Li's team, and the collection of biological media (urine, saliva and nasal fluid) was&#xD;
      conducted by Dr. Junfeng (Jim) Zhang's team. In addition, subjects were instructed to measure&#xD;
      the peak expiratory flow (PEF) at 7am and 9pm daily and recorded their asthma symptoms at&#xD;
      home with the assistance from their guardian(s). The biological media (urine, saliva and&#xD;
      nasal fluid) collected was subsequently analyzed by Dr. Junfeng (Jim) Zhang's team for health&#xD;
      indicators.&#xD;
&#xD;
      Each subject had access to the result of clinical assessment and health indicator in&#xD;
      biological media, as well as free consultation from the medical teams of Drs. Zhen Li and&#xD;
      Feng Li. Every subject was remunerated with 1000RMB (equivalent to 152 US dollars) and given&#xD;
      a peak expiratory flow meter (worth less than 10 US dollars). All information collected from&#xD;
      study subjects were recorded under their subject ID number and kept confidential. Only&#xD;
      de-identified data was shared between collaborating investigators. Statistical analysis&#xD;
      including mixed-effects models will be conducted on the data collected.&#xD;
    </textblock>
  </detailed_description>
  <overall_status>Unknown status</overall_status>
  <last_known_status>Active, not recruiting</last_known_status>
  <start_date type="Actual">January 17, 2017</start_date>
  <completion_date type="Anticipated">December 2020</completion_date>
  <primary_completion_date type="Actual">April 22, 2017</primary_completion_date>
  <phase>N/A</phase>
  <study_type>Interventional</study_type>
  <has_expanded_access>No</has_expanded_access>
  <study_design_info>
    <allocation>Randomized</allocation>
    <intervention_model>Crossover Assignment</intervention_model>
    <intervention_model_description>Every study subject had the air in their bedroom processed by an air filtration device (with a pre-filter, a HEPA filter and an active carbon filter) for two weeks (active comparator arm), processed by a placebo air filtration device (which did not possess the HEPA filter and active carbon filters) for two weeks (placebo arm), and underwent a two-week washout period (no use of air filtration device) between the two intervention periods.</intervention_model_description>
    <primary_purpose>Prevention</primary_purpose>
    <masking>Triple (Participant, Care Provider, Outcomes Assessor)</masking>
    <masking_description>The real air filtration device and the placebo air filtration device looked identical, however the placebo air filtration device lacked the HEPA and active carbon filters which functioned to remove airborne pollutants.</masking_description>
  </study_design_info>
  <primary_outcome>
    <measure>Fractional exhaled nitric oxide (FeNO)</measure>
    <time_frame>Change of FeNO after the end of the two-week intervention compared to the start of the two-week intervention period</time_frame>
    <description>Fractional exhaled nitric oxide (FeNO) was measured using the NIOX machine</description>
  </primary_outcome>
  <secondary_outcome>
    <measure>Asthma symptoms</measure>
    <time_frame>Within 24 hours before the start of intervention and within 24 hours after the end of intervention</time_frame>
    <description>Asthma symptom was evaluated by the Asthma Control Test (ACT) questionnaire</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Peak expiratory flow (PEF)</measure>
    <time_frame>Measured at 7am and 9pm daily during the two-week intervention</time_frame>
    <description>The maximum speed of exhalation (PEF) was measured by a handheld PEF meter (Koka Peak Expiratory Flow Meter)</description>
  </secondary_outcome>
  <secondary_outcome>
    <measure>Lung function</measure>
    <time_frame>Within 24 hours before the start of intervention and within 24 hours after the end of intervention</time_frame>
    <description>Lung function was assessed by spirometry (Jaeger MasterScreen™ PFT system) and impulse oscillometry (Jaeger MasterScreenTM IOS).</description>
  </secondary_outcome>
  <other_outcome>
    <measure>Malondialdehyde (MDA) concentration in urine</measure>
    <time_frame>Within 24 hours before the start of intervention and within 24 hours after the end of intervention</time_frame>
    <description>Malondialdehyde (MDA) concentration in urine was measured using the thiobarbituric acid derivatization method and high-performance liquid chromatography (HPLC)</description>
  </other_outcome>
  <other_outcome>
    <measure>8-OHdG concentration in urine</measure>
    <time_frame>Within 24 hours before the start of intervention and within 24 hours after the end of intervention</time_frame>
    <description>Concentration of 8-hydroxydeoxyguanosine (8-OHdG) in urine was measured by solid phase extraction and liquid chromatography-mass spectrometry (LC-MS)</description>
  </other_outcome>
  <other_outcome>
    <measure>Malondialdehyde (MDA) concentration in nasal fluid</measure>
    <time_frame>Within 24 hours before the start of intervention and within 24 hours after the end of intervention</time_frame>
    <description>Malondialdehyde (MDA) concentration in nasal fluid was measured using the thiobarbituric acid derivatization method and high-performance liquid chromatography (HPLC)</description>
  </other_outcome>
  <other_outcome>
    <measure>Malondialdehyde (MDA) concentration in saliva</measure>
    <time_frame>Within 24 hours before the start of intervention and within 24 hours after the end of intervention</time_frame>
    <description>Malondialdehyde (MDA) concentration in saliva was measured using the thiobarbituric acid derivatization method and high-performance liquid chromatography (HPLC)</description>
  </other_outcome>
  <other_outcome>
    <measure>Interleukin-6 level in saliva</measure>
    <time_frame>Within 24 hours before the start of intervention and within 24 hours after the end of intervention</time_frame>
    <description>The concentration of interleukin-6 in saliva was measured by enzyme-linked immunosorbent assay (ELISA)</description>
  </other_outcome>
  <other_outcome>
    <measure>Eosinophil cationic protein concentration in saliva</measure>
    <time_frame>Within 24 hours before the start of intervention and within 24 hours after the end of intervention</time_frame>
    <description>The concentration of eosinophil cationic protein in saliva was measured by enzyme-linked immunosorbent assay (ELISA)</description>
  </other_outcome>
  <other_outcome>
    <measure>Blood eosinophil</measure>
    <time_frame>Only once at the time of enrollment into the study</time_frame>
    <description>Blood eosinophil was assessed using the blood routine test</description>
  </other_outcome>
  <other_outcome>
    <measure>Allergen profile</measure>
    <time_frame>Only once at the time of enrollment into the study</time_frame>
    <description>The IgE antibody for 19 allergens were assessed using serum samples from study subjects.</description>
  </other_outcome>
  <other_outcome>
    <measure>Chemical exposure</measure>
    <time_frame>During 1 week of the study</time_frame>
    <description>Personal exposure to chemicals including flame retardant and organophosphates was assessed using silicone wristbands that were worn on the wrist of study subjects for 1 week</description>
  </other_outcome>
  <number_of_arms>2</number_of_arms>
  <enrollment type="Actual">43</enrollment>
  <condition>Asthma in Children</condition>
  <arm_group>
    <arm_group_label>Bedroom air filtered by an air filtration device</arm_group_label>
    <arm_group_type>Active Comparator</arm_group_type>
    <description>The air in the bedroom of study subjects in the active comparator arm was filtered by an air filtration device which processed air through a pre-filter, a high efficiency particular air (HEPA) filter and an active carbon filter. The duration of being in the active comparator arm was 2 weeks.</description>
  </arm_group>
  <arm_group>
    <arm_group_label>Bedroom air filtered by a placebo air filtration device</arm_group_label>
    <arm_group_type>Placebo Comparator</arm_group_type>
    <description>The air in the bedroom of subjects in the placebo arm was filtered by a placebo air filtration device that looked identical to the real air filtration device but did not possess the HEPA filter and the active carbon filter. The duration of being in the placebo arm was 2 weeks.</description>
  </arm_group>
  <intervention>
    <intervention_type>Device</intervention_type>
    <intervention_name>Bedroom air filtered by an air filtration device to remove airborne pollutants</intervention_name>
    <description>The air in the bedroom of study subjects in the active comparator arm was processed by an air filtration device which pulled air through a pre-filter, a high efficiency particular air (HEPA) filter and an active carbon filter continuously. The air in the bedroom of subjects in the placebo arm was processed by a placebo air filtration device that looked identical to the real air filtration device but did not possess the HEPA filter and the active carbon filter. Each subject was assigned to the active comparator arm and the placebo arm in a randomized order with a two-week washout period scheduled in-between. The subjects, their guardians and the study staff that assessed the health indicators of the subjects were blinded to this order till the end of the study.</description>
    <arm_group_label>Bedroom air filtered by a placebo air filtration device</arm_group_label>
    <arm_group_label>Bedroom air filtered by an air filtration device</arm_group_label>
  </intervention>
  <eligibility>
    <criteria>
      <textblock>
        Inclusion Criteria:&#xD;
&#xD;
        An eligible child is defined as:&#xD;
&#xD;
          -  Aged between 5 and 14&#xD;
&#xD;
          -  Have physician-diagnosed asthma&#xD;
&#xD;
          -  Had at least one asthma attack during the past year&#xD;
&#xD;
        An eligible household is defined as:&#xD;
&#xD;
          -  Has an eligible child&#xD;
&#xD;
          -  Located in Shanghai, China&#xD;
&#xD;
        Exclusion Criteria:&#xD;
&#xD;
          -  Children who were current smokers or have diseases other than asthma are exclude from&#xD;
             study participation&#xD;
      </textblock>
    </criteria>
    <gender>All</gender>
    <minimum_age>5 Years</minimum_age>
    <maximum_age>14 Years</maximum_age>
    <healthy_volunteers>No</healthy_volunteers>
  </eligibility>
  <overall_official>
    <last_name>Michael H. Bergin, PhD</last_name>
    <role>Study Director</role>
    <affiliation>Duke University</affiliation>
  </overall_official>
  <overall_official>
    <last_name>Junfeng Zhang, PhD</last_name>
    <role>Principal Investigator</role>
    <affiliation>Duke University</affiliation>
  </overall_official>
  <overall_official>
    <last_name>James J. Schauer, PhD</last_name>
    <role>Principal Investigator</role>
    <affiliation>University of Wisconsin, Madison</affiliation>
  </overall_official>
  <overall_official>
    <last_name>Yinping Zhang, PhD</last_name>
    <role>Principal Investigator</role>
    <affiliation>Tsinghua University</affiliation>
  </overall_official>
  <overall_official>
    <last_name>Feng Li, MD</last_name>
    <role>Principal Investigator</role>
    <affiliation>Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine</affiliation>
  </overall_official>
  <location>
    <facility>
      <name>Shanghai General Hospital</name>
      <address>
        <city>Shanghai</city>
        <state>Shanghai</state>
        <zip>201620</zip>
        <country>China</country>
      </address>
    </facility>
  </location>
  <location_countries>
    <country>China</country>
  </location_countries>
  <verification_date>March 2020</verification_date>
  <study_first_submitted>August 24, 2017</study_first_submitted>
  <study_first_submitted_qc>September 13, 2017</study_first_submitted_qc>
  <study_first_posted type="Actual">September 14, 2017</study_first_posted>
  <last_update_submitted>March 19, 2020</last_update_submitted>
  <last_update_submitted_qc>March 19, 2020</last_update_submitted_qc>
  <last_update_posted type="Actual">March 23, 2020</last_update_posted>
  <responsible_party>
    <responsible_party_type>Principal Investigator</responsible_party_type>
    <investigator_affiliation>Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine</investigator_affiliation>
    <investigator_full_name>Zhen Li</investigator_full_name>
    <investigator_title>Attending Physician</investigator_title>
  </responsible_party>
  <keyword>asthma</keyword>
  <keyword>air pollution</keyword>
  <keyword>air filtration</keyword>
  <keyword>indoor air quality</keyword>
  <keyword>respiratory health</keyword>
  <condition_browse>
    <!-- CAUTION:  The following MeSH terms are assigned with an imperfect algorithm            -->
    <mesh_term>Asthma</mesh_term>
  </condition_browse>
  <patient_data>
    <sharing_ipd>Undecided</sharing_ipd>
  </patient_data>
  <!-- Results have not yet been posted for this study                                          -->
</clinical_study>


download date: ClinicalTrials.gov processed this data on September 20, 2023
link text: Link to the current ClinicalTrials.gov record.
url: https://clinicaltrials.gov/ct2/show/NCT03282864
org study id: [2016] 48
nct id: NCT03282864
lead sponsor: 
collaborator: 
collaborator: 
collaborator: 
collaborator: 
has dmc: No
is fda regulated drug: No
is fda regulated device: No
This study uses a crossover study design to examine the impact of a two-week bedroom based
      indoor air filtration on the concentration of indoor airborne pollutants, personal exposure
      to airborne pollutants and health indicators among asthmatic children living in Shanghai,
      China
This study recruited asthmatic children aged 5 to 14 who were living in Shanghai, China.
      Every study subject had the air in their bedroom processed by an air filtration device (with
      a pre-filter, a HEPA filter and an active carbon filter) for two weeks (active comparator
      arm), processed by a placebo air filtration device (which did not possess the HEPA filter and
      active carbon filters) for two weeks (placebo arm), and underwent a two-week washout period
      (no use of air filtration device) between the two intervention periods. The doors and windows
      of the bedroom were instructed to be kept closed during the intervention periods. The
      sequence of being in the active comparator arm and the placebo arm was randomized for each
      subject. The subject, their guardian and researchers who have direct interaction with the
      study subjects do not know this sequence until after the end of the study.

      The study protocol was approved by IRB at Shanghai First People's Hospital, Duke University
      and University of Wisconsin at Madison. A sample size of 40 was calculated using fractional
      exhaled nitric oxide (FeNO) as the primary outcome where statistical significance was set at
      0.05, power at 90%, and between-subject variance and covariance were estimated from existing
      literature. Four additional subjects were added to the estimated sample size of 40 to account
      for potential dropouts. Subjects were recruited from patients who attended the outpatient
      clinic of the Pediatrics Department of Shanghai First People's Hospital (south section) by
      Dr. Zhen Li and Dr. Junfeng Zhang's team. Assent was obtained from all study subjects and
      written informed consent was obtained from their guardians.

      During the study, Dr. Michael Bergin's team and Dr. Yinping Zhang's team installed the air
      filtration devices in the subject's bedroom and measured the indoor concentration, outdoor
      concentration and personal exposure to airborne pollutants including PM2.5, ozone and
      volatile organic compounds. Dr. James Schauer's team analyzed the physical, chemical and
      bioactivity of the airborne particles collected and had no direct contact with the study
      subjects.

      Each subject attended 5 clinical visits at the Shanghai First People's Hospital (South
      Section) accompanied by their guardian where clinical assessment (of lung function,
      fractional exhaled nitric oxide, asthma symptom blood draw) was performed by Drs. Zhen Li and
      Feng Li's team, and the collection of biological media (urine, saliva and nasal fluid) was
      conducted by Dr. Junfeng (Jim) Zhang's team. In addition, subjects were instructed to measure
      the peak expiratory flow (PEF) at 7am and 9pm daily and recorded their asthma symptoms at
      home with the assistance from their guardian(s). The biological media (urine, saliva and
      nasal fluid) collected was subsequently analyzed by Dr. Junfeng (Jim) Zhang's team for health
      indicators.

      Each subject had access to the result of clinical assessment and health indicator in
      biological media, as well as free consultation from the medical teams of Drs. Zhen Li and
      Feng Li. Every subject was remunerated with 1000RMB (equivalent to 152 US dollars) and given
      a peak expiratory flow meter (worth less than 10 US dollars). All information collected from
      study subjects were recorded under their subject ID number and kept confidential. Only
      de-identified data was shared between collaborating investigators. Statistical analysis
      including mixed-effects models will be conducted on the data collected.
allocation: Randomized
intervention model: Crossover Assignment
intervention model description: Every study subject had the air in their bedroom processed by an air filtration device (with a pre-filter, a HEPA filter and an active carbon filter) for two weeks (active comparator arm), processed by a placebo air filtration device (which did not possess the HEPA filter and active carbon filters) for two weeks (placebo arm), and underwent a two-week washout period (no use of air filtration device) between the two intervention periods.
primary purpose: Prevention
masking: Triple (Participant, Care Provider, Outcomes Assessor)
masking description: The real air filtration device and the placebo air filtration device looked identical, however the placebo air filtration device lacked the HEPA and active carbon filters which functioned to remove airborne pollutants.
measure: Fractional exhaled nitric oxide (FeNO)
time frame: Change of FeNO after the end of the two-week intervention compared to the start of the two-week intervention period
description: Fractional exhaled nitric oxide (FeNO) was measured using the NIOX machine
measure: Asthma symptoms
time frame: Within 24 hours before the start of intervention and within 24 hours after the end of intervention
description: Asthma symptom was evaluated by the Asthma Control Test (ACT) questionnaire
measure: Peak expiratory flow (PEF)
time frame: Measured at 7am and 9pm daily during the two-week intervention
description: The maximum speed of exhalation (PEF) was measured by a handheld PEF meter (Koka Peak Expiratory Flow Meter)
measure: Lung function
time frame: Within 24 hours before the start of intervention and within 24 hours after the end of intervention
description: Lung function was assessed by spirometry (Jaeger MasterScreen™ PFT system) and impulse oscillometry (Jaeger MasterScreenTM IOS).
measure: Malondialdehyde (MDA) concentration in urine
time frame: Within 24 hours before the start of intervention and within 24 hours after the end of intervention
description: Malondialdehyde (MDA) concentration in urine was measured using the thiobarbituric acid derivatization method and high-performance liquid chromatography (HPLC)
measure: 8-OHdG concentration in urine
time frame: Within 24 hours before the start of intervention and within 24 hours after the end of intervention
description: Concentration of 8-hydroxydeoxyguanosine (8-OHdG) in urine was measured by solid phase extraction and liquid chromatography-mass spectrometry (LC-MS)
measure: Malondialdehyde (MDA) concentration in nasal fluid
time frame: Within 24 hours before the start of intervention and within 24 hours after the end of intervention
description: Malondialdehyde (MDA) concentration in nasal fluid was measured using the thiobarbituric acid derivatization method and high-performance liquid chromatography (HPLC)
measure: Malondialdehyde (MDA) concentration in saliva
time frame: Within 24 hours before the start of intervention and within 24 hours after the end of intervention
description: Malondialdehyde (MDA) concentration in saliva was measured using the thiobarbituric acid derivatization method and high-performance liquid chromatography (HPLC)
measure: Interleukin-6 level in saliva
time frame: Within 24 hours before the start of intervention and within 24 hours after the end of intervention
description: The concentration of interleukin-6 in saliva was measured by enzyme-linked immunosorbent assay (ELISA)
measure: Eosinophil cationic protein concentration in saliva
time frame: Within 24 hours before the start of intervention and within 24 hours after the end of intervention
description: The concentration of eosinophil cationic protein in saliva was measured by enzyme-linked immunosorbent assay (ELISA)
measure: Blood eosinophil
time frame: Only once at the time of enrollment into the study
description: Blood eosinophil was assessed using the blood routine test
measure: Allergen profile
time frame: Only once at the time of enrollment into the study
description: The IgE antibody for 19 allergens were assessed using serum samples from study subjects.
measure: Chemical exposure
time frame: During 1 week of the study
description: Personal exposure to chemicals including flame retardant and organophosphates was assessed using silicone wristbands that were worn on the wrist of study subjects for 1 week
arm group label: Bedroom air filtered by an air filtration device
arm group type: Active Comparator
description: The air in the bedroom of study subjects in the active comparator arm was filtered by an air filtration device which processed air through a pre-filter, a high efficiency particular air (HEPA) filter and an active carbon filter. The duration of being in the active comparator arm was 2 weeks.
arm group label: Bedroom air filtered by a placebo air filtration device
arm group type: Placebo Comparator
description: The air in the bedroom of subjects in the placebo arm was filtered by a placebo air filtration device that looked identical to the real air filtration device but did not possess the HEPA filter and the active carbon filter. The duration of being in the placebo arm was 2 weeks.
intervention type: Device
intervention name: Bedroom air filtered by an air filtration device to remove airborne pollutants
description: The air in the bedroom of study subjects in the active comparator arm was processed by an air filtration device which pulled air through a pre-filter, a high efficiency particular air (HEPA) filter and an active carbon filter continuously. The air in the bedroom of subjects in the placebo arm was processed by a placebo air filtration device that looked identical to the real air filtration device but did not possess the HEPA filter and the active carbon filter. Each subject was assigned to the active comparator arm and the placebo arm in a randomized order with a two-week washout period scheduled in-between. The subjects, their guardians and the study staff that assessed the health indicators of the subjects were blinded to this order till the end of the study.
arm group label: Bedroom air filtered by a placebo air filtration device
arm group label: Bedroom air filtered by an air filtration device
criteria: 
gender: All
minimum age: 5 Years
maximum age: 14 Years
healthy volunteers: No
last name: Michael H. Bergin, PhD
role: Study Director
affiliation: Duke University
last name: Junfeng Zhang, PhD
role: Principal Investigator
affiliation: Duke University
last name: James J. Schauer, PhD
role: Principal Investigator
affiliation: University of Wisconsin, Madison
last name: Yinping Zhang, PhD
role: Principal Investigator
affiliation: Tsinghua University
last name: Feng Li, MD
role: Principal Investigator
affiliation: Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine
facility: 
country: China
responsible party type: Principal Investigator
investigator affiliation: Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine
investigator full name: Zhen Li
investigator title: Attending Physician
mesh term: Asthma
sharing ipd: Undecided