Intervention Study on the Health Impact of Air Filters in Chinese Adults

January 12, 2016 updated by: Haidong Kan, Fudan University

Cardiopulmonary Benefits of Reducing Indoor Particles of Outdoor Origin: a Randomized Double-blind Crossover Trial of Air Purifiers

This study aimed to evaluate whether a short-term indoor air purifier intervention improves cardiopulmonary health based on a randomized double-blind crossover trial

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

We conducted a randomized double-blind crossover trial among 35 healthy college students in Shanghai, China in 2014. These students lived in dormitories that were randomized into two groups and alternated the use of true or sham air purifiers for 48 hours with a 2-week wash-out interval.All participants and research staff were blinded to the group assignment. We requested all participants to stay in their dormitory room with the windows/doors closed throughout each 48-hour intervention period. We delivered foods and drinks to each room during the intervention period. All interventions started at 8 a.m. to avoid issues related to diurnal variation. We evaluated health endpoints and drew blood immediately after the completion of each 48-hour intervention. We measured 14 circulating biomarkers of inflammation, coagulation and vasoconstriction, lung function, blood pressure (BP), and fractional exhaled nitric oxide (FeNO).

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
35

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • China
    • Shanghai
      • Shanghai, Shanghai, China, 200032
        • Department of Environmental Health, School of Public Health, Fudan University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years to 26 years (Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Healthy college students aged between 18 and 26
  • All the subjects should stay indoor almost the entire time, and stayed within the central urban area of shanghai during the wash-out period.

Exclusion Criteria:

  • current smokers or ever smokers
  • chronic respiratory diseases
  • chronic cardiovascular diseases
  • acute infections
  • medication use in recent one month

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: True air purification
One group of subjects used an intervention of true air purifiers placed in the center of the room.
Behavioral: Air purifiers
The 10 dormitory rooms were randomized into two groups of 5 rooms each. One group used an air purifier placed in the center of the room for 48 hours corresponding to one weekend, followed by a 2-week washout period, and another 48 hours of using a sham air purifier under the same conditions. The other group simply reversed the order in which the real and sham air purifiers were used. All rooms used the same qualified air purifiers (model FAP04, 3M Filtrete), with the only difference being removal of the filter gauze in the sham purifiers. The air pollution auto-sensing feature of air purifiers was disabled in both groups. All participants and research staff were blinded to the group assignment. We requested all participants to stay in their dormitory room with the windows/doors closed throughout each 48-hour intervention period.
Other Names:
  • Air filtration
Sham Comparator: Sham air purification
This group of subjects used an intervention of sham air purifiers under the same conditions with true purifiers with the only difference being removal of the filter gauze in the sham purifiers.
Behavioral: Air purifiers
The 10 dormitory rooms were randomized into two groups of 5 rooms each. One group used an air purifier placed in the center of the room for 48 hours corresponding to one weekend, followed by a 2-week washout period, and another 48 hours of using a sham air purifier under the same conditions. The other group simply reversed the order in which the real and sham air purifiers were used. All rooms used the same qualified air purifiers (model FAP04, 3M Filtrete), with the only difference being removal of the filter gauze in the sham purifiers. The air pollution auto-sensing feature of air purifiers was disabled in both groups. All participants and research staff were blinded to the group assignment. We requested all participants to stay in their dormitory room with the windows/doors closed throughout each 48-hour intervention period.
Other Names:
  • Air filtration

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Circulating Biomarkers
Time Frame: Blood samples were drawn within one hour after the intervention, and lab analysis was completed in the next 10 days
Peripheral blood samples (5 ml) were drawn by a nurse, separated into serum and plasma, and stored at -80 ℃ within 30 minutes. We measured the levels of 14 circulating biomarkers: (1) 8 biomarkers of inflammation, including C-reactive protein (CRP), fibrinogen, P-selection, monocyte chemoattractant protein-1 (MCP-1), interleukin-1b, interleukin-6, tumor necrosis factor-α (TNF-α) and myeloperoxidase; (2) 4 biomarkers of coagulation, including soluble CD40 ligand (sCD40L), plasminogen activator inhibitor-1, tissue plasminogen activator and D-Dimer; and (3) 2 biomarkers of vasoconstriction, including endothelin-1 and angiotensin-converting enzyme.
Blood samples were drawn within one hour after the intervention, and lab analysis was completed in the next 10 days
Lung Function
Time Frame: Within 1 hour after the end of the two-day intervention
A respiratory physician measured forced vital capacity, forced expiratory volume in 1 second and peak expiratory flow of each participant using the JAEGER Masterlab equipment (Würzburg, Germany) that meets the American Thoracic Society criteria. The volume signal was calibrated at least once on a testing day with a 3.0 L syringe connected to the pneumotachograph in accordance with the manufacturers' recommendations. We instructed participants to perform at least three forced expiratory lung function maneuvers in order to obtain a minimum of two acceptable and reproducible values, and we recorded the best results.
Within 1 hour after the end of the two-day intervention

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Blood Pressure
Time Frame: Within one hour after the 2-day intervention
After sitting in a quiet room for at least 5 min, participants had their left upper arm BP measured by trained technicians using a mercury sphygmomanometer at least three times with 2-min minimum intervals between measurements. The second and third sets of readings were averaged to obtain systolic BP and diastolic BP. Pulse pressure was calculated as the difference between systolic BP and diastolic BP. If the differences among the three measurements were bigger than 5 mmHg, a new round of measurements were arranged.
Within one hour after the 2-day intervention
Fractional Exhaled Nitric Oxide
Time Frame: within 1 hour after the two-day intervention
FeNO is an established biomarker of respiratory inflammation, and has been widely used in epidemiological studies because of its high sensitivity, specificity and non-invasive nature. We measured FeNO levels using a portable NIOX MINO machine (Aerocrine AB, Solna, Sweden) according to standardized procedures by the American Thoracic Society and the European Respiratory Society.
within 1 hour after the two-day intervention

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Fudan University

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Director: Haidong Kan, PhD, School of Public Health，Fudan University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
September 1, 2014

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
November 1, 2014

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
November 1, 2014

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
September 7, 2014

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 11, 2014

First Posted (Estimate)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
September 15, 2014

Study Record Updates

Last Update Posted (Estimate)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
January 13, 2016

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 12, 2016

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
January 1, 2016

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • FDUEH-1

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Inflammation

Clinical Trials on Air purifiers

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Cookie Settings

We use cookies to ensure that we give you the best experience on our website. For more details carefully read our Privacy and Cookies Policy. ...>>>You can change your preferences or withdraw your consent at any time by deleting the cookies from your website or computer as described in the policy. Please accept it and choose your preferences by ticking the corresponding boxes in the "Manage Settings" section below. Please carefully read our Terms of Service before you proceed with using any part of this website.
«Manage Settings