An interventional study of Circuit Breathing Intervention and Diaphragmatic Breathing in E Cigarette Use, sponsored by Chulalongkorn University. Recruiting at 1 site in Thailand. Open to participants aged 15 Years to 25 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-10-20.
Sponsored by Chulalongkorn University · Not applicable, Interventional, and Treatment
This study aims to evaluate the effects of a six-week behavioral circuit breathing training intervention on smoking cessation and respiratory function compared with diaphragmatic breathing training and usual daily activities
A three-arm experimental study will include 45 male and female e-cigarette users aged 15-25 years, randomly allocated to a behavioral circuit breathing training group (n = 15), a diaphragmatic breathing training group (n = 15), or a control group (n = 15) that maintains usual daily activities. The two intervention groups will perform their respective breathing training programs three days per week for six weeks. Outcomes will be assessed before and after the intervention.
172 studies on the registry are indexed under Vaping; 75 are open to participants now.
This study's planned enrollment of 45 is below the median of 105 across 144 interventional studies indexed under Vaping.
Browse Vaping studies →Chulalongkorn University is the lead sponsor of 320 studies on the registry; 64 are open to participants now.
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Exclusion Criteria:
Other: Circuit Breathing Intervention
Other: Diaphragmatic Breathing
The circuit breathing intervention consists of five stations: paper suction using a straw, blowing a toy pinwheel, incentive spirometry, balloon blowing, and weighted diaphragmatic breathing. Participants will rest for 1 minute between stations.
Participants will begin by breathing normally for 1 minute before starting diaphragmatic breathing. The diaphragmatic breathing exercise will consist of inhaling through the nose for 4 seconds and exhaling through the nose for 6 seconds, continuously for 10 minutes per set. Participants will rest for 1 minute between sets and complete a total of 3 sets.
Tobacco Craving Questionnaire-Short Form (TCQ-SF) Score
Craving will be assessed using the 12-item TCQ-SF. The questionnaire is a self-report measure using a 7-point Likert scale, ranging from 1 (strongly disagree) to 7 (strongly agree). Higher scores indicate greater tobacco craving.
Time frame: Change from baseline Tobacco Craving Questionnaire-Short Form (TCQ-SF) score at 6 weeks.
Smoking Cessation Status and Behaviors
This self-report questionnaire consists of seven items assessing 7-day point-prevalence abstinence, duration of smoking cessation, smoking cessation behaviors, and attempts to quit smoking.
Time frame: Change from baseline smoking cessation status and behaviors at 6 weeks.
Penn State Electronic Cigarette Dependence Index Score
E-cigarette dependence will be assessed using the Penn State Electronic Cigarette Dependence Index. The scale consists of 10 items, with a maximum total score of 20.
Time frame: Change from baseline Penn State Electronic Cigarette Dependence Index score at 6 weeks.
Pulmonary function (Forced Expiratory Volume in one second; FEV1)
The participants were instructed to sit on a chair and wear a nose clip. The researcher provided them with a detailed set of instructions to ensure they performed the maneuver correctly according to guidelines of the American Thoracic Society (ATS). Prior to demonstrating forced inspiration and expiration, the participants were asked to perform three cycles of slow normal breathing as part of the FVC maneuver. FEV1 (L) will be reported in liter (L).
Time frame: Change from baseline FEV1 at 6 weeks.
Pulmonary function (The ratio of the forced expiratory volume in the first one second to the forced vital capacity of the lungs; FEV1/FVC)
The participants were instructed to sit on a chair and wear a nose clip. The researcher provided them with a detailed set of instructions to ensure they performed the maneuver correctly according to guidelines of the American Thoracic Society (ATS). Prior to demonstrating forced inspiration and expiration, the participants were asked to perform three cycles of slow normal breathing as part of the FVC maneuver. FEV1/FVC will be reported in percent (%).
Time frame: Change from baseline FEV1/FVC at 6 weeks.
Pulmonary function (Maximal voluntary ventilation; MVV)
The participants were instructed to sit on a chair and wear a nose clip. The researcher provided them with a detailed set of instructions to ensure they performed the maneuver correctly according to guidelines of the American Thoracic Society (ATS). During the MVV maneuver, participants were instructed to demonstrate in rapid and forceful inhalation and exhalation for a duration of 10 seconds. MVV will be reported in liter per minute (L/min).
Time frame: Change from baseline MVV at 6 weeks.
Pulmonary function (Forced expiratory flow at 25-75%)
The participants were instructed to sit on a chair and wear a nose clip. The researcher provided them with a detailed set of instructions to ensure they performed the maneuver correctly according to guidelines of the American Thoracic Society (ATS). Prior to demonstrating forced inspiration and expiration, the participants were asked to perform three cycles of slow normal breathing as part of the FVC maneuver.
Time frame: Change from baseline FEF 25-75% at 6 weeks.
Respiratory muscle strength
Respiratory muscle strength was evaluated by measuring Maximal Inspiratory Pressure (MIP) and Maximal Expiratory Pressure (MEP) in centimeters of water (cmH2O). The participants were seated and utilized a portable handheld mouth pressure meter (MicroRPM), along with a nose clip. To assess MIP, participants were instructed to exhale until they emptied their lungs at the point of functional residual capacity (FRC). Participants held the device to their mouth and forcefully inhaled for 1-2 seconds. For the measurement of MEP, participants were directed to inhale until their lungs were completely filled with air, starting from the total lung capacity (TLC) point. Participants were asked to maintain the device on their mouth and forcefully exhaled for 1-2 seconds.
Time frame: Change from baseline Maximal Inspiratory Pressure (MIP) and Maximal Expiratory Pressure (MEP) at 6 weeks.
WHOQOL-BREF Score
Quality of life will be assessed using the World Health Organization Quality of Life questionnaire (WHOQOL). Participants will complete the 26-item questionnaire independently using an electronic device through Google Forms. Completion will take approximately 10 minutes.
Time frame: Change from baseline WHOQOL-BREF Score at 6 weeks.
Pittsburgh Sleep Quality Index (PSQI) Global Score
Sleep quality will be assessed using the Pittsburgh Sleep Quality Index (PSQI). Participants will complete the 19-item questionnaire independently using an electronic device through Google Forms. Completion will take approximately 10 minutes.
Time frame: Change from baseline Pittsburgh Sleep Quality Index (PSQI) Global Score at 6 weeks.
Fractional Exhaled Nitric Oxide (FeNO)
Fractional exhaled nitric oxide (FeNO) will be measured using a device equipped with a bacterial filter and mouthpiece. Participants will place their lips around the mouthpiece and exhale into the device for 6 seconds while maintaining the indicator ball within the designated range. Results will be recorded in parts per million (ppm). The procedure will take approximately 5 minutes.
Time frame: Change from baseline FeNO level (ppm) at 6 weeks.
Peak Nasal Inspiratory Flow (PNIF)
Peak nasal inspiratory flow will be measured using a peak nasal inspiratory flow meter. Participants will perform the breathing maneuver according to the study procedure, and the measurement will be recorded in liters per second (L/s).
Time frame: Change from baseline PNIF (L/s) at 6 weeks.
Aerobic Fitness (Maximum oxygen consumption; VO2max)
Aerobic fitness will be assessed using a 3-minute step test. Participants will step up and down in time with an audible metronome for 3 minutes.
Time frame: Change from baseline VO2max at 6 weeks.
Plan to share: No
No publications or documents are linked to this record.
Started Sep 2026 (actual). Primary completion is estimated for Dec 2026, 3 months after the start.
Of 102 non-industry interventional studies with no phase under Vaping, half reached primary completion within 23 months of starting (the median), counting those still running; a quarter within 10 and three quarters within 36. This study's planned 3 months is below that.
Counting every sponsor, half of 103 studies reached it within 18 months; a quarter within 9 and three quarters within 36.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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