The Health Benefits of Indoor Air Filtration Among Children

NCT04835337 | Completed

• 1 other identifier: 202032
• Study Type: interventional
• Target: 105
• Locations: 1 country
• Sites: 1

Brief Summary

This study aims to explore the health benefits of air purifier on the impact of air pollutants on children's health.

Conditions

Protective Effect of Air Purifier on Children's Health

Outcome Measures

Primary Outcomes (20)

• 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.

  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.

  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.

  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.

  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.

  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.

  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.

  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.

  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.

  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.

  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.

  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.

  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).

  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).

  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).

  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).

  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).

  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).

  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).

  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.

  Baseline and at the end of each 60 days intervention period

Secondary Outcomes (19)

• Changes of CRP

  Baseline and at the end of each 60 days intervention period

• Changes of 8-OHdG

  Baseline and at the end of each 60 days intervention period

• Changes of metabolites in exhaled breath condensate

  Baseline and at the end of each 60 days intervention period

• Changes of the role of alertness

  Baseline and at the end of each 60 days intervention period

• Changes of the role of orientation

  Baseline and at the end of each 60 days intervention period

Study Arms (2)

Air purifier

EXPERIMENTAL

Participants in this group receive an intervention of real air purifiers placed in the indoor environment.

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.

Behavioral: Sham Air Purifiers

Interventions

Air Purifiers BEHAVIORAL

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.

Air purifier

Sham Air Purifiers BEHAVIORAL

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.

Control

Eligibility Criteria

• Age: 10 Years - 12 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Child (0-17)

You may qualify if:

• ≤ 12 years old
• Volunteer to participate in this study

You may not qualify if:

• 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

Sponsors & Collaborators

• Tiantian Li: lead

Study Sites (1)

National Institute of Environmental Health, Chinese Center for Disease Control and Prevention

Beijing, 100021, China

Location

Related Publications (1)

• 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.

  PMID: 39621320 DERIVED

MeSH Terms

Interventions

Air Filters

Intervention Hierarchy (Ancestors)

Filtration; Chemistry Techniques, Analytical; Investigative Techniques; Equipment and Supplies

Study Officials

• Tiantian Li

  National Institute of Environmental Health, Chinese Center for Disease Control and Prevention

  STUDY DIRECTOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Purpose: PREVENTION
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER GOV
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: professor

Study Record Dates

• First Submitted: March 30, 2021
• First Posted: April 8, 2021
• Study Start: April 10, 2021
• Primary Completion: December 15, 2021
• Study Completion: May 15, 2022
• Last Updated: September 24, 2024

Record last verified: 2024-09

Locations

CN (1)