Protective Effect of Air Purifier on Children's HealthNCT04835337
The Health Benefits of Indoor Air Filtration Among Children
A study testing Air Purifiers in people with Protective Effect of Air Purifier on Children's Health, run by Tiantian Li at 1 site in China.
Trial summary
This study aims to explore the health benefits of air purifier on the impact of air pollutants on children's health. Read more about this study
- Who is it for?
- Ages 10 to 12 yearsHealthy volunteers can take part
- Conditions the study is for
- Protective Effect of Air Purifier on Children's Health
- What is being tested?
- Air Purifiers
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 105 participants
- Where
- 1 siteChina
- Study dates
- 10 Apr 2021to 15 May 2022
- 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 10 to 12 years
- All sexes
- Healthy volunteers accepted
- Child
Who may be able to join
- 10 ≤ 12 years old
- Volunteer to participate in this study
Who cannot join
- Current and past medical history, including asthma, childhood diabetes, childhood hypertension, behavior-related diseases
- Students who plan to transfer or move within six months
- Unable to cooperate with follow-up
Trial locations and contacts
1 site in 1 country.
China1 site
National Institute of Environmental Health, Chinese Center for Disease Control and Prevention
Beijing, 100021
About this study
Official title: Investigating the Health Benefits of Indoor Air Filtration Among Children: a Randomized Crossover Trial in Jiaozuo, China
This study aims to explore the health benefits of air purifier on the impact of air pollutants on children's health.
Read the detailed description
From April 2021 to December 2021, researchers conduct a randomized double-blind crossover trial on about 100 healthy children in Jiaozuo City, Henan Province. The children are divided into two groups according to their classes and alternated the use of true or sham purifiers devices, including air purifiers and fresh air ventilation. Air purifiers are installed in the classroom and bedrooms of the children. Fresh air ventilation is installed in the classroom. A total of 4 epidemiological surveys are conducted on the subjects, with an interval of 60 days or more. All participants and research staffs were blinded to the group assignment. In addition, air pollutant exposure monitoring, questionnaire surveys, physical examinations, and biological sample collection are conducted on the research subjects each time. The biological samples are further tested for the concentration levels of related biomarkers such as the respiratory system, cardiovascular system, metabolic system, and nervous system. Furthermore, comprehensive evaluation of children's behavioral ability is also carried out. Ambient PM2.5 and indoor PM2.5 exposure concentrations are monitored in the study.
- Being tested
- Air Purifiers, Sham Air Purifiers
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Air PurifiersBehavioural
Students are divided into two groups: intervention group and control group. The intervention team places an air purifier in the indoor environment to intervene. All the indoor environment of the group use the same qualified air purifier, and all participants and research staffs are blinded to the group assignment.
Sham Air PurifiersBehavioural
The control group is also intervened. The intervention is to place a sham air purifier (remove the filter screen) in the indoor environment, and all the indoor environment use the same air purifier as the intervention group. All participants and research staffs are blinded to the group assignment.
| Study group | Role | What they receive |
|---|---|---|
| Air purifier | Experimental | Participants in this group receive an intervention of real air purifiers placed in the indoor environment. Receives: Behavioral: Air Purifiers |
| Control | Sham comparator | Participants in this group receive an intervention of sham air purifiers, we just remove the filter in the purifiers, and the other treatments are the same as the real purification group. Receives: Behavioral: Sham Air Purifiers |
What is being measured
The primary outcome is the main question the study is designed to answer.
Changes of FEV1
The forced expiratory volume in 1 s (FEV1) is measured using a smart spirometer (Model A1, BreathHome, China) supervised by professional medical staff. Before the pulmonary function test, subjects will practice several times by themselves. During the examination, each subject stands and clamps the nose clip, and repeats the test, with the best result as the criterion. FEV1 reflect pulmonary function.
Measured: Baseline and at the end of each 60 days intervention period
Changes of FVC
The forced vital capacity (FVC) is measured using spirometer (Model A1, BreathHome, China). FVC reflects the expiratory resistance of large airways.
Measured: Baseline and at the end of each 60 days intervention period
Changes of FEV1/FVC ratio
The FEV1/FVC ratio is measured using smart spirometer (Model A1, BreathHome, China). FEV1/FVC ratio reflects the status of airway obstruction.
Measured: Baseline and at the end of each 60 days intervention period
Changes of PEF
The peak expiratory flow (PEF) is measured using smart spirometer (Model A1, BreathHome, China). PEF reflects airway patency and respiratory muscle strength.
Measured: Baseline and at the end of each 60 days intervention period
Changes of FEF25-75%
The forced expiratory flow at 25-75% of FVC (FEF25-75%) is measured using smart spirometer (Model A1, BreathHome, China). FEF25-75% reflects the small airway obstruction.
Measured: Baseline and at the end of each 60 days intervention period
Changes of MEF75%
The maximal expiratory flow at 75% of FVC (MEF75%) is measured using smart spirometer (Model A1, BreathHome, China). MEF75% reflects the terminal stage of expiratory flow rate.
Measured: Baseline and at the end of each 60 days intervention period
Changes of MEF50%
The maximal expiratory flow at 50% of FVC (MEF50%) is measured using smart spirometer (Model A1, BreathHome, China). MEF50% reflects the interim stage of expiratory flow rate.
Measured: Baseline and at the end of each 60 days intervention period
Changes of MEF25%
The maximal expiratory flow at 25% of FVC (MEF25%) is measured using smart spirometer (Model A1, BreathHome, China). MEF25% reflects the early stage of expiratory flow rate.
Measured: Baseline and at the end of each 60 days intervention period
Changes of FeNO
Use NIOX VERO Sensor to measure fractional exhaled nitric oxide (FeNO) as a biomarker for airway inflammation level. After deep breathing, the subjects gently inhaled into the device. The instrument showed FeNO level of the subjects.
Measured: Baseline and at the end of each 60 days intervention period
Changes of FeCO
Use Pico Smokerlyzer to measure fractional exhaled carbon monoxide (FeCO). After deep breathing, the subjects held their breath for 15 seconds and then gently inhaled into the device. The instrument showed FeCO level and the estimated value of carboxyhemoglobin in blood.
Measured: Baseline and at the end of each 60 days intervention period
Changes of Blood Pressure
The professional staffs wrap the BP cuff around the left upper arm of children to measure BP using the Omron electronic sphygmomanometers (OMROM, J751). BP is measured at 2-minute intervals, with a total of three measurements taken. If the difference of BP values between the last two measurements exceeds 5 mmHg, additional measurements are performed. Each child is allowed to measure BP at least three times and up to five times. The BP indicators includes SBP, DBP, MAP and PP.
Measured: Baseline and at the end of each 60 days intervention period
Changes of heart rate variability
The trained staffs conduct a 3-minute comprehensive assessment using the handheld electrocardiographic recorder-CarePatch (ECG-H01, Hangzhou Proton Technology Co., Ltd., China) to measured HRV. The time-domain indicators include standard deviation of all normal-to-normal intervals (SDNN), the root mean square of successive differences between adjacent normal cycles (rMSSD), the percentage of adjacent NN interval differences greater than 50 ms (pNN50); and the frequency-domain indicators include very low frequency (VLF), low frequency (LF), high frequency (HF), the ratio of LF to HF (LF/HF). To eliminate possible error, subjects are conducted by the same trained staff using the same instrument.
Measured: Baseline and at the end of each 60 days intervention period
Changes of PR interval
The trained staff use a 12-lead electrocardiogram (ECG) monitor to measure the participants' the interval of the beginning of the P wave to the beginning of the QRS complex (PR interval).
Measured: Baseline and at the end of each 60 days intervention period
Changes of QRS duration
The trained staff use a 12-lead electrocardiogram (ECG) monitor to measure the participants' the interval of the beginning of Q wave to the end of the S wave (QRS duration).
Measured: Baseline and at the end of each 60 days intervention period
Changes of QT interval
The trained staff use a 12-lead electrocardiogram (ECG) monitor to measure the participants' the interval from the onset of the QRS complex to the end of the T wave (QT interval).
Measured: Baseline and at the end of each 60 days intervention period
Changes of QTc interval
The trained staff use a 12-lead electrocardiogram (ECG) monitor to measure the participants' the QT correction for rate (QTc interval).
Measured: Baseline and at the end of each 60 days intervention period
Changes of RV5
The trained staff use a 12-lead electrocardiogram (ECG) monitor to measure the participants' the amplitude of the R-wave in lead V5 (RV5).
Measured: Baseline and at the end of each 60 days intervention period
Changes of SV1
The trained staff use a 12-lead electrocardiogram (ECG) monitor to measure the participants' the S-wave depth in lead V1 (SV1).
Measured: Baseline and at the end of each 60 days intervention period
Changes of RV5+SV1
The trained staff use a 12-lead electrocardiogram (ECG) monitor to measure the participants' the sum of the R-wave amplitude in lead V5 and the S-wave amplitude in lead V1(RV5+SV1).
Measured: Baseline and at the end of each 60 days intervention period
Changes of academic performance
The assessment of academic performance consists of standardised scores (maths, chinese and total) and the relative rank of the scores within grade. Standardised scores are converted from raw scores (with minimum value of 0 and maximum of 100) according to the number of exams and classes, indicating the position of the sample value in the normal distribution curve, with higher value showing better outcome. Rankings are converted from place rankings of raw values, with lower value showing better outcome.
Measured: Baseline and at the end of each 60 days intervention period
Secondary outcomes (19)
Changes of CRP
Detect the concentration of C-reactive protein in blood sample to examine the different level of inflammation between the group of intervention and control.
Measured: Baseline and at the end of each 60 days intervention period
Changes of 8-OHdG
Detect the concentration of 8-hydroxydeoxyguanosine (8-OHdG) in urine sample as a marker of generalized, cellular oxidative stress to DNA.
Measured: Baseline and at the end of each 60 days intervention period
Changes of metabolites in exhaled breath condensate
Collect the exhaled breath condensate and identify the metabolites of exhaled breath condensate using Ultra-high performance liquid chromatography-tandem mass spectrometry.
Measured: Baseline and at the end of each 60 days intervention period
Changes of the role of alertness
Alertness can be measured by the Attention Network Test and reflects an individual's acquisition and maintenance of a state of alertness to a particular type of information or target.
Measured: Baseline and at the end of each 60 days intervention period
Changes of the role of orientation
Orientation can be measured by the Attention Network Test and reflects an individual's selective attention to externally useful information.
Measured: Baseline and at the end of each 60 days intervention period
Changes of the role of conflict
Conflict can be measured by the Attention Network Test and reflects an individual's ability to process conflicting information.
Measured: Baseline and at the end of each 60 days intervention period
Changes of Wisconsin Card Sorting Test indicators
WCST contains absolute indicators of cognitive executive functioning which include level of conceptualisation, persistence and set maintenance. The cognitive absolute indicators include conceptual thinking includes complete correct (TC), complete error (TE), non-persistent error (NPE), conceptual level response (CLR) and category completed (CC), persistence includes persistent response (PR) and persistent error (PE), and pooling maintenance includes inability to maintain pooling (FM).WCST percentage metrics are similar in meaning to the absolute metrics, and can be categorised into the level of conceptualisation and the Two dimensions of persistence. Cognitive percentage indicators include conceptual thinking consists of total correct percentage (%TC), total error percentage (%TE), non-persistent error percentage (%NPE), and conceptual level response percentage (%NPE); persistence consists of persistent response percentage (%PR) and persistent error percentage (%PE).
Measured: Baseline and at the end of each 60 days intervention period
Changes of the position total number
The position total number is the number of all position-related stimuli during the N-back test. The subjects need to remember how each position changed and judge whether a duplicate position stimulus appeared after N rounds.
Measured: Baseline and at the end of each 60 days intervention period
Changes of the position number correct
The position number correct is the number of times during the N-back test that the subjects were able to correctly judge whether or not a repeated position appeared in N rounds. A higher number correct indicates that the tester performed better in remembering and recognising the location.
Measured: Baseline and at the end of each 60 days intervention period
Changes of the position percentage correct
Changes of position percentage correct is the accuracy of the -N-back test subjects in position-related tasks, expressed as a percentage. It is calculated as (number of locations correct ÷ total number of location stimuli) × 100%. A high rate of correctness indicates that the subjects' accuracy in location memory is high.
Measured: Baseline and at the end of each 60 days intervention period
Changes of the color total number
The color total number is the number of all colour-related stimuli during the -N-back test. The subjects were required to remember the colour changes and determine whether a repeated colour stimulus has occurred after N-backs.
Measured: Baseline and at the end of each 60 days intervention period
Changes of the color number correct
The color number correct is the number of times during the N-back test that the subjects were able to correctly judge whether a repeated colour appeared or not in N rounds. A higher correct count indicates that the tester performed better in colour memory and recognition.
Measured: Baseline and at the end of each 60 days intervention period
Changes of the color percentage correct
Changes of color percentage correct is is the subjects' accuracy in colour-related tasks during the N-back test, expressed as a percentage. It is calculated as (number of colours correct ÷ total number of colour stimuli) × 100%. A high rate of correctness indicates that the subjects' accuracy in colour memory is high.
Measured: Baseline and at the end of each 60 days intervention period
Changes of the shape total number
The shape total number is the number of all shape stimuli during the N-back test. The subjects need to remember the shape changes and judge whether a repeated shape stimulus has appeared after the N-back.
Measured: Baseline and at the end of each 60 days intervention period
Changes of the shape number correct
The shape number correct is the number of times during the N-back test that the subjects were able to correctly judge whether or not a repeated shape appeared in N rounds. A higher number correct indicates that the subjects performed better in shape memory and recognition.
Measured: Baseline and at the end of each 60 days intervention period
Changes of the shape percentage correct
Changes of shape percentage correct is the subjects' accuracy in shape-related tasks during the N-back test, expressed as a percentage. It is calculated as (number of shapes correct ÷ total number of shape stimuli) × 100%. A high rate of correctness indicates that the subjects' accuracy in shape memory is high.
Measured: Baseline and at the end of each 60 days intervention period
Changes of proteins in serum
Collect peripheral venous blood, extract the serum, and identify the proteins of serum samples using 4D-label free technology.
Measured: Baseline and at the end of each 60 days intervention period
Changes in biomarkers identified from other omics
Collect peripheral venous blood, exhaled breath condensate, urine, saliva, oral cells, oral swabs, nasal swabs, skin swabs, nails and feces samples, then identify the biomarkers by conducting transcriptomic, microbiome analyses, etc.
Measured: Through study completion, up to 10 years
Changes in other targeted biomarkers of interest
Collect peripheral venous blood, exhaled breath condensate, urine, saliva, oral cells, oral swabs, nasal swabs, skin swabs, nails and feces samples, then identify the other targeted biomarkers of interest.
Measured: Through study completion, up to 10 years
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted8 Apr 2021
- Study start10 Apr 2021
- Primary completion15 Dec 2021
- Study completion15 May 2022
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 Protective Effect of Air Purifier on Children's HealthStudies of the same condition, open and under way.
- 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
- Prevention
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 105 participants (actual)
Sponsor and investigators
- Lead sponsor
- Tiantian Li
- Sponsor type
- Other government
- Responsible party
- Sponsor-investigator, Tiantian Li, Centers for Disease Control and Prevention, China
- Investigators
- Tiantian Li, Study director, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04835337
- Sponsor's protocol ID
- 202032
- Status last verified
- Sep 2024
- First submitted
- 30 Mar 2021
- Last updated
- 24 Sep 2024
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Lei J, Sun Q, Chen R, Zhu Y, Zhou L, Xue X, Fang J, Du Y, Wang Y, Li T, Kan H. Respiratory Benefits of Multisetting Air Purification in Children: A Cluster Randomized Crossover Trial. JAMA Pediatr. 2025 Feb 1;179(2):122-128. doi: 10.1001/jamapediatrics.2024.5049.
PubMed 39621320
Study at a glance
From the registry record, last updated by the sponsor on 24 Sep 2024. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Investigating the Health Benefits of Indoor Air Filtration Among Children: a Randomized Crossover Trial in Jiaozuo, China
- ClinicalTrials.gov ID
- NCT04835337
- Acronym / sponsor ID
- 202032
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 105 participants (actual)
- Lead sponsor
- Tiantian LiOther government
- Study start
- 10 Apr 2021 (actual)
- Primary completion
- 15 Dec 2021 (actual)
- Study completion
- 15 May 2022 (actual)
- First posted
- 8 Apr 2021 (actual)
- 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.
This study aims to explore the health benefits of air purifier on the impact of air pollutants on children's health.
Detailed description
From April 2021 to December 2021, researchers conduct a randomized double-blind crossover trial on about 100 healthy children in Jiaozuo City, Henan Province. The children are divided into two groups according to their classes and alternated the use of true or sham purifiers devices, including air purifiers and fresh air ventilation. Air purifiers are installed in the classroom and bedrooms of the children. Fresh air ventilation is installed in the classroom. A total of 4 epidemiological surveys are conducted on the subjects, with an interval of 60 days or more. All participants and research staffs were blinded to the group assignment. In addition, air pollutant exposure monitoring, questionnaire surveys, physical examinations, and biological sample collection are conducted on the research subjects each time. The biological samples are further tested for the concentration levels of related biomarkers such as the respiratory system, cardiovascular system, metabolic system, and nervous system. Furthermore, comprehensive evaluation of children's behavioral ability is also carried out. Ambient PM2.5 and indoor PM2.5 exposure concentrations are monitored in the study.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind (participant, investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Air purifier | Experimental | Behavioral: Air PurifiersParticipants in this group receive an intervention of real air purifiers placed in the indoor environment. |
| Control | Sham comparator | Behavioral: Sham Air PurifiersParticipants in this group receive an intervention of sham air purifiers, we just remove the filter in the purifiers, and the other treatments are the same as the real purification group. |
Who may qualify
- Ages
- 10 to 12 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child
Key inclusion criteria (2 listed)
- 10 ≤ 12 years old
- Volunteer to participate in this study
Key exclusion criteria (3 listed)
- Current and past medical history, including asthma, childhood diabetes, childhood hypertension, behavior-related diseases
- Students who plan to transfer or move within six months
- Unable to cooperate with follow-up
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 |
|---|---|---|
| Air PurifiersStudents are divided into two groups: intervention group and control group. The intervention team places an air purifier in the indoor environment to intervene. All the indoor environment of the group use the same qualified air purifier, and all participants and research staffs are blinded to the group assignment. | Behavioural | Air purifier |
| Sham Air PurifiersThe control group is also intervened. The intervention is to place a sham air purifier (remove the filter screen) in the indoor environment, and all the indoor environment use the same air purifier as the intervention group. All participants and research staffs are blinded to the group assignment. | Behavioural | Control |
Primary outcome
Changes of FEV1
Time frame: Baseline and at the end of each 60 days intervention period
The forced expiratory volume in 1 s (FEV1) is measured using a smart spirometer (Model A1, BreathHome, China) supervised by professional medical staff. Before the pulmonary function test, subjects will practice several times by themselves. During the examination, each subject stands and clamps the nose clip, and repeats the test, with the best result as the criterion. FEV1 reflect pulmonary function.
Changes of FVC
Time frame: Baseline and at the end of each 60 days intervention period
The forced vital capacity (FVC) is measured using spirometer (Model A1, BreathHome, China). FVC reflects the expiratory resistance of large airways.
Changes of FEV1/FVC ratio
Time frame: Baseline and at the end of each 60 days intervention period
The FEV1/FVC ratio is measured using smart spirometer (Model A1, BreathHome, China). FEV1/FVC ratio reflects the status of airway obstruction.
Changes of PEF
Time frame: Baseline and at the end of each 60 days intervention period
The peak expiratory flow (PEF) is measured using smart spirometer (Model A1, BreathHome, China). PEF reflects airway patency and respiratory muscle strength.
Changes of FEF25-75%
Time frame: Baseline and at the end of each 60 days intervention period
The forced expiratory flow at 25-75% of FVC (FEF25-75%) is measured using smart spirometer (Model A1, BreathHome, China). FEF25-75% reflects the small airway obstruction.
Changes of MEF75%
Time frame: Baseline and at the end of each 60 days intervention period
The maximal expiratory flow at 75% of FVC (MEF75%) is measured using smart spirometer (Model A1, BreathHome, China). MEF75% reflects the terminal stage of expiratory flow rate.
Changes of MEF50%
Time frame: Baseline and at the end of each 60 days intervention period
The maximal expiratory flow at 50% of FVC (MEF50%) is measured using smart spirometer (Model A1, BreathHome, China). MEF50% reflects the interim stage of expiratory flow rate.
Changes of MEF25%
Time frame: Baseline and at the end of each 60 days intervention period
The maximal expiratory flow at 25% of FVC (MEF25%) is measured using smart spirometer (Model A1, BreathHome, China). MEF25% reflects the early stage of expiratory flow rate.
Changes of FeNO
Time frame: Baseline and at the end of each 60 days intervention period
Use NIOX VERO Sensor to measure fractional exhaled nitric oxide (FeNO) as a biomarker for airway inflammation level. After deep breathing, the subjects gently inhaled into the device. The instrument showed FeNO level of the subjects.
Changes of FeCO
Time frame: Baseline and at the end of each 60 days intervention period
Use Pico Smokerlyzer to measure fractional exhaled carbon monoxide (FeCO). After deep breathing, the subjects held their breath for 15 seconds and then gently inhaled into the device. The instrument showed FeCO level and the estimated value of carboxyhemoglobin in blood.
Changes of Blood Pressure
Time frame: Baseline and at the end of each 60 days intervention period
The professional staffs wrap the BP cuff around the left upper arm of children to measure BP using the Omron electronic sphygmomanometers (OMROM, J751). BP is measured at 2-minute intervals, with a total of three measurements taken. If the difference of BP values between the last two measurements exceeds 5 mmHg, additional measurements are performed. Each child is allowed to measure BP at least three times and up to five times. The BP indicators includes SBP, DBP, MAP and PP.
Changes of heart rate variability
Time frame: Baseline and at the end of each 60 days intervention period
The trained staffs conduct a 3-minute comprehensive assessment using the handheld electrocardiographic recorder-CarePatch (ECG-H01, Hangzhou Proton Technology Co., Ltd., China) to measured HRV. The time-domain indicators include standard deviation of all normal-to-normal intervals (SDNN), the root mean square of successive differences between adjacent normal cycles (rMSSD), the percentage of adjacent NN interval differences greater than 50 ms (pNN50); and the frequency-domain indicators include very low frequency (VLF), low frequency (LF), high frequency (HF), the ratio of LF to HF (LF/HF). To eliminate possible error, subjects are conducted by the same trained staff using the same instrument.
Changes of PR interval
Time frame: Baseline and at the end of each 60 days intervention period
The trained staff use a 12-lead electrocardiogram (ECG) monitor to measure the participants' the interval of the beginning of the P wave to the beginning of the QRS complex (PR interval).
Changes of QRS duration
Time frame: Baseline and at the end of each 60 days intervention period
The trained staff use a 12-lead electrocardiogram (ECG) monitor to measure the participants' the interval of the beginning of Q wave to the end of the S wave (QRS duration).
Changes of QT interval
Time frame: Baseline and at the end of each 60 days intervention period
The trained staff use a 12-lead electrocardiogram (ECG) monitor to measure the participants' the interval from the onset of the QRS complex to the end of the T wave (QT interval).
Changes of QTc interval
Time frame: Baseline and at the end of each 60 days intervention period
The trained staff use a 12-lead electrocardiogram (ECG) monitor to measure the participants' the QT correction for rate (QTc interval).
Changes of RV5
Time frame: Baseline and at the end of each 60 days intervention period
The trained staff use a 12-lead electrocardiogram (ECG) monitor to measure the participants' the amplitude of the R-wave in lead V5 (RV5).
Changes of SV1
Time frame: Baseline and at the end of each 60 days intervention period
The trained staff use a 12-lead electrocardiogram (ECG) monitor to measure the participants' the S-wave depth in lead V1 (SV1).
Changes of RV5+SV1
Time frame: Baseline and at the end of each 60 days intervention period
The trained staff use a 12-lead electrocardiogram (ECG) monitor to measure the participants' the sum of the R-wave amplitude in lead V5 and the S-wave amplitude in lead V1(RV5+SV1).
Changes of academic performance
Time frame: Baseline and at the end of each 60 days intervention period
The assessment of academic performance consists of standardised scores (maths, chinese and total) and the relative rank of the scores within grade. Standardised scores are converted from raw scores (with minimum value of 0 and maximum of 100) according to the number of exams and classes, indicating the position of the sample value in the normal distribution curve, with higher value showing better outcome. Rankings are converted from place rankings of raw values, with lower value showing better outcome.
19 secondary outcomes
Changes of CRP
Time frame: Baseline and at the end of each 60 days intervention period
Changes of 8-OHdG
Time frame: Baseline and at the end of each 60 days intervention period
Changes of metabolites in exhaled breath condensate
Time frame: Baseline and at the end of each 60 days intervention period
Changes of the role of alertness
Time frame: Baseline and at the end of each 60 days intervention period
Changes of the role of orientation
Time frame: Baseline and at the end of each 60 days intervention period
Changes of the role of conflict
Time frame: Baseline and at the end of each 60 days intervention period
Changes of Wisconsin Card Sorting Test indicators
Time frame: Baseline and at the end of each 60 days intervention period
Changes of the position total number
Time frame: Baseline and at the end of each 60 days intervention period
Changes of the position number correct
Time frame: Baseline and at the end of each 60 days intervention period
Changes of the position percentage correct
Time frame: Baseline and at the end of each 60 days intervention period
Changes of the color total number
Time frame: Baseline and at the end of each 60 days intervention period
Changes of the color number correct
Time frame: Baseline and at the end of each 60 days intervention period
Changes of the color percentage correct
Time frame: Baseline and at the end of each 60 days intervention period
Changes of the shape total number
Time frame: Baseline and at the end of each 60 days intervention period
Changes of the shape number correct
Time frame: Baseline and at the end of each 60 days intervention period
Changes of the shape percentage correct
Time frame: Baseline and at the end of each 60 days intervention period
Changes of proteins in serum
Time frame: Baseline and at the end of each 60 days intervention period
Changes in biomarkers identified from other omics
Time frame: Through study completion, up to 10 years
Changes in other targeted biomarkers of interest
Time frame: Through study completion, up to 10 years
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 24 Sep 2024.
- Derived from this study: PubMed 39621320Lei J, Sun Q, Chen R, Zhu Y, Zhou L, Xue X, Fang J, Du Y, Wang Y, Li T, Kan H. Respiratory Benefits of Multisetting Air Purification in Children: A Cluster Randomized Crossover Trial. JAMA Pediatr. 2025 Feb 1;179(2):122-128. doi: 10.1001/jamapediatrics.2024.5049.
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.
Tiantian Li study director
National Institute of Environmental Health, Chinese Center for Disease Control and Prevention
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Air Purifiers in people with Protective Effect of Air Purifier on Children's Health, run by Tiantian Li at 1 site in China.
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 2 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 24 Sep 2024. 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 China. 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. Some participants in this study may receive a placebo. 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?
Changes of FEV1 (time frame: Baseline and at the end of each 60 days intervention period). The study lists 20 primary outcomes in all. 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 NCT04835337, 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 24 Sep 2024.