Use of Expired Air Carbon Monoxide Testing in Clinical Tobacco Treatment Settings

Carbon monoxide (CO) testing is considered an easy, noninvasive, and objective contribution to the assessment of smoking behavior, as CO is rapidly absorbed into the bloodstream when lit cigarettes or cigars are inhaled. CO testing is a medically important billable outpatient service that can contribute to sustainability of face to face tobacco use treatment services by clinicians. This article reviews research on the clinical use of CO testing to provide biomedical feedback in assessing smoking behavior, educating smokers on tobacco health effects, assisting with treatment planning, and as a motivational tool to encourage people to become tobacco free. Further research can focus on how to best incorporate CO testing into clinical practice, including more research on outcomes and methods to ensure that insurers reimburse for testing and improved ways to use CO testing to initiate attempts to quit tobacco use, to maintain cessation, and to prevent relapse.

A cross-sectional study of determinants of indoor environmental exposures in households with and without chronic exposure to biomass fuel smoke

BACKGROUND

Burning biomass fuels indoors for cooking is associated with high concentrations of particulate matter (PM) and carbon monoxide (CO). More efficient biomass-burning stoves and chimneys for ventilation have been proposed as solutions to reduce indoor pollution. We sought to quantify indoor PM and CO exposures in urban and rural households and determine factors associated with higher exposures. A secondary objective was to identify chronic vs. acute changes in cardiopulmonary biomarkers associated with exposure to biomass smoke.

METHODS

We conducted a census survey followed by a cross-sectional study of indoor environmental exposures and cardiopulmonary biomarkers in the main household cook in Puno, Peru. We measured 24-hour indoor PM and CO concentrations in 86 households. We also measured PM2.5 and PM10 concentrations gravimetrically for 24 hours in urban households and during cook times in rural households, and generated a calibration equation using PM2.5 measurements.

RESULTS

In a census of 4903 households, 93% vs. 16% of rural vs. urban households used an open-fire stove; 22% of rural households had a homemade chimney; and <3% of rural households participated in a national program encouraging installation of a chimney. Median 24-hour indoor PM2.5 and CO concentrations were 130 vs. 22 μg/m3 and 5.8 vs. 0.4 ppm (all p<0.001) in rural vs. urban households. Having a chimney did not significantly reduce median concentrations in 24-hour indoor PM2.5 (119 vs. 137 μg/m3; p=0.40) or CO (4.6 vs. 7.2 ppm; p=0.23) among rural households with and without chimneys. Having a chimney did not significantly reduce median cook-time PM2.5 (360 vs. 298 μg/m3, p=0.45) or cook-time CO concentrations (15.2 vs. 9.4 ppm, p=0.23). Having a thatched roof (p=0.007) and hours spent cooking (p=0.02) were associated with higher 24-hour average PM concentrations. Rural participants had higher median exhaled CO (10 vs. 6 ppm; p=0.01) and exhaled carboxyhemoglobin (1.6% vs. 1.0%; p=0.04) than urban participants.

CONCLUSIONS

Indoor air concentrations associated with biomass smoke were six-fold greater in rural vs. urban households. Having a homemade chimney did not reduce environmental exposures significantly. Measures of exhaled CO provide useful cardiopulmonary biomarkers for chronic exposure to biomass smoke.

Utilizing exhaled carbon monoxide measurement with self-declared smoking cessation: enhancing abstinence effectiveness in Taiwanese outpatients

BACKGROUND

Presently, the Department of Health Taiwan has begun to fund a smoking cessation program, and the annual cessation rate was 8.9% in 2010. This study aims to see whether to enhance abstinence effectiveness by utilizing exhaled carbon monoxide (COExh) measurement with self-declared smoking cessation.

METHODS

The longitudinal prospective study gathered 33 subjects on quitting smoking with the motivation to join the grant program in chest outpatient from August 2009 to July 2010. Overall, subjects were given nicotine replacement therapy (NRT) in the first stage, and explored abstinence rate results in evaluation stage. The cutoff point of COExh 6 ppm or less than (≤) and patients' self-declared abstinence reports confirmed a smoking cessation success status. Point abstinences were defined as the smokers refrained from smoking at least 7 days, while continuous abstinences were defined as nonsmoking at least 3, 6 and 12 months.

RESULTS

The validities were 198 tracking results for two stages (P < 0.001 vs P < 0.001), and sensitivity (56.5% vs 60.0%), specificity (90.1% vs 82.6%), positive predictive value (63.4% vs 60.0%) and negative predictive value (87.2% vs 82.6%) were detected. Moreover, the validities were 33 results for point and continuous abstinences at 3 month (P < 0.001 vs P < 0.001), and higher successful rates. Point abstinence rates at 3, 6 and 12 months follow-up for overall subjects were 27.2%, 15.2% and 18.1%, respectively. Continuous abstinence rates at 3, 6 and 12 months were 24.2%, 12.1% and 12.1%, respectively.

CONCLUSIONS

Utilizing COExh measurement with self-declared smoking cessation enhanced abstinence effectiveness in Taiwanese outpatients.

Exhaled Carbon Monoxide Levels in Forty Resistant to Cessation Male Smokers after Six Months of Full Switch to Electronic Cigarettes (e-Cigs) or to A Tobacco Heating Systems (THS)

Cigarette smoke releases several toxic chemicals and carcinogens including carbon monoxide (CO). This study examined the levels of exhaled CO in smokers switching to electronic cigarettes (e-Cigs) or a tobacco heating system (THS) and their level of compliance six months after switching. On the basis of their own preferences, 40 male smokers unwilling or unable to stop smoking were switched to e-Cigs or THSs for six months (20 subjects in each group). Nicotine addiction and levels of carbon monoxide in the exhaled breath (eCO) were measured at baseline (the latter also at six months). The Shapiro Wilk test, graphical methods, Student T test or Mann-Whitney test were used to assess the normal distribution of variables and differences between the two groups after six months. The two groups showed no difference at baseline, but a significant higher addiction score in smokers choosing THS. E-Cig and THS showed significant reduced levels of eCO (both %COHb and COppm) after six months, which were within the range of non-smoker status. Reduced levels of %COHb did not significantly differ between the two groups, whilst the THS group had a significantly lower reduction in levels of COppm vs the e-Cig group (p < 0.05). Both e-Cigs and THSs are capable of significantly reducing eCO at least in the medium term, hence constituting a viable tobacco harm reduction approach in smokers who are unwilling or unable to stop smoking.

Factors influencing the levels of exhaled carbon monoxide in asthmatic children

OBJECTIVE

Bronchial asthma is characterised by chronic airway inflammation commonly associated with increased oxidative stress. Exhaled carbon monoxide (eCO) levels could act as markers of both oxidative stress and allergic inflammation. We aimed to study eCO levels in asthmatics and detect the possible factors influencing them.

METHODS

We studied 241 asthmatic children and 75 healthy children. The differences in eCO levels among various asthmatic phenotypes and the correlations between eCO and other measured parameters (spirometric indices, Asthma Control Test score, exhaled nitric oxide, total IgE, blood eosinophils and marker of oxidative damage of proteins) were analysed.

RESULTS

Levels of eCO widely differed according to the selected characteristics of asthma. Asthmatics showed higher eCO concentrations than controls (1.44 ± 0.12 ppm vs. 0.91 ± 0.11 ppm, p < 0.001). Acute exacerbation of asthma was accompanied by a significant increase in eCO compared to the clinically controlled stage (2.17 ± 0.36 ppm vs. 1.33 ± 0.13 ppm, p < 0.001). Atopic, non-atopic asthma and asthma associated with allergic rhinitis (AR) showed elevated levels of eCO. The levels of eCO negatively correlated with the marker of protein oxidation in asthmatics, especially in atopic form and during acute exacerbation.

CONCLUSIONS

In a population of asthmatic children, eCO levels could be considered as a marker of both allergic inflammation and oxidative stress in the airways. Concomitant AR and asthma control were the most important factors affecting the levels of eCO in asthmatic children. However, our results do not support the use of routine eCO in the clinical practice.

Exhaled Biomarkers for Point-of-Care Diagnosis: Recent Advances and New Challenges in Breathomics

Cancers, chronic diseases and respiratory infections are major causes of mortality and present diagnostic and therapeutic challenges for health care. There is an unmet medical need for non-invasive, easy-to-use biomarkers for the early diagnosis, phenotyping, predicting and monitoring of the therapeutic responses of these disorders. Exhaled breath sampling is an attractive choice that has gained attention in recent years. Exhaled nitric oxide measurement used as a predictive biomarker of the response to anti-eosinophil therapy in severe asthma has paved the way for other exhaled breath biomarkers. Advances in laser and nanosensor technologies and spectrometry together with widespread use of algorithms and artificial intelligence have facilitated research on volatile organic compounds and artificial olfaction systems to develop new exhaled biomarkers. We aim to provide an overview of the recent advances in and challenges of exhaled biomarker measurements with an emphasis on the applicability of their measurement as a non-invasive, point-of-care diagnostic and monitoring tool.

The Effects of Auricular Acupressure on Smoking Cessation for Male College Students

The purpose of the study was to examine the effects of auricular acupressure for smoking cessation on male college students. The experimental group ( n = 27) received auricular acupressure on specific acupoints for smoking cessation, whereas the control group ( n = 26) received sham auricular acupressure on nonspecific acupoints. Participants received 6 weeks of auricular acupressure intervention. For the experimental group, auricular acupressure was applied to the shenmen, lung, subcortex, hunger, stomach, and mouth. The data of nicotine dependence, self-efficacy for smoking cessation, and exhaled carbon monoxide were collected for both group 3 times: before intervention, after 3 weeks of the intervention, and after 6 weeks of the intervention. Statistical differences between the two groups from pretest to posttest emerged in self-efficacy for smoking cessation ( p = .048) and exhaled carbon monoxide ( p < .001), but not for nicotine dependence.

Ten-year experience of smoking cessation in a single center in Japan

BACKGROUND

Long-term, real-world data, as opposed to academic or research data, on outcomes of smoking cessation clinics are scarce. We assessed patient outcomes over a 10-year period at a smoking cessation clinic in a community teaching hospital in Japan and explored predictors of successful smoking cessation.

METHODS

We used data from a prospective registry of cigarette smokers who participated in a 3-month smoking cessation program comprising combined pharmacological treatment and cognitive behavioral therapy and explored factors associated with program execution and successful smoking cessation. The primary outcome was smoking cessation, defined by quitting completely between the 8-week and 12-week sessions, with verification according to exhaled carbon monoxide (CO) level of ≤10 ppm.

RESULTS

Between August 2007 and December 2017, 813 patients with nicotine dependence participated in the program. The number of participants decreased after Japan׳s 2010 tobacco tax increase. Among participants, 433 (53.3%) completed the program. In multivariate analysis, the number of cigarettes smoked daily (odds ratio [OR] 0.98, 95% confidence interval [CI] 0.96, 0.99), cardiovascular disease (OR 1.75, 95% CI 1.16, 2.68), chronic obstructive pulmonary disease (OR 1.74, 95% CI 1.10, 2.78), and gastric/duodenal ulcer (OR 1.77, 95% CI 1.04, 3.08) were significantly associated with program completion. Among program completers, 288 (66.5%) achieved smoking cessation. Exhaled CO level (OR 0.94, 95% CI 0.93, 0.97) and mental disorders (OR 0.53, 95% CI 0.33, 0.85) were negatively associated with successful smoking cessation.

CONCLUSIONS

Baseline exhaled CO level and mental disorders were significantly associated with either success or failure of smoking cessation.

Correlation of exhaled carbon monoxide level with disease severity in chronic obstruction pulmonary disease

Introduction:

Amplification of airway inflammation and its destruction due to oxidative stress is a major step in the pathogenesis of chronic obstruction pulmonary disease (COPD). Exhaled carbon monoxide (eCO) may be quantified to evaluate the airway inflammation and oxidative stress in such patients.

Objectives:

To assess the disease severity of COPD and treatment response by measuring eCO as a biomarker.

Materials and Methods:

COPD patients diagnosed according to the global initiative for chronic obstructive lung disease guidelines and healthy individuals as controls were selected. One hundred and fifty patients with COPD and 125 controls were included in the study. Participants were further subdivided on the basis of their smoking habits. Clinical examinations and spirometry were done to diagnose COPD by following the standard protocol. eCO was measured using a piCO + Smokerlyzer (Breath CO Monitor, Bedfont Scientific Ltd., Kent, UK). It was a single-center cross-sectional study.

Results:

Mean (± standard error of mean) CO levels in ex-smokers with COPD were higher (5.21 ± 1.546 ppm; P < 0.05) than in nonsmoking controls (1.52 ± 0.571 ppm) but were lower than in current smokers with COPD (12.55 ± 4.514 ppm; P < 0.05). eCO levels were higher in current smokers with COPD (12.55 ± 4.514 ppm; P < 0.05) compared to healthy smokers (9.71 ± 5.649). There was a negative correlation between eCO and forced expiratory volume in 1 s (FEV1) in COPD (r = −0.28; P < 0.05). The mean eCO level was decreased (6.291–4.332; P < 0.001) with improvement in lung function (FEV1 38.75%–50.65%: P < 0.05) after treatment with inhaled steroid.

Conclusion:

Our study concludes that quantification of eCO level in COPD varies with different grades of airway obstruction and to measure the treatment response. Measuring the level of eCO can be used to assess the indirect assessment of airway inflammation, oxidative stress, and severity of airway obstruction in COPD patients.

Evaluation of smoking status: comparison of self-reports with exhaled carbon monoxide analysis in university students in the Islamic Republic of Iran

Background

Smoking is considered the leading risk factor for many chronic diseases and deaths worldwide. Thus, it is important to determine the number of smokers before implementing tobacco control initiatives. Due to stigma and deterrent measures, it is impossible to access smokers through a self-report questionnaire.

Aims

To compare exhaled carbon monoxide levels with self-reports among university students in the Islamic Republic of Iran.

Methods

This cross-sectional study included a convenience sample of 60 university students recruited in 2016 in Tehran. There were 30 women and 30 men with an average age of 23.1 (±15.6) years. They were interviewed using an adaptation of the International Union Against Tuberculosis and Lung Diseases questionnaire and further assessed by breath analysis. Smoking status was compared and then correlated with the resultant carbon monoxide levels at a cutoff of 6 ppm.

Results

Mean cigarette consumption was 4.7 (±1.8) each day and smoking status was reported as 19 (31.7%) current smokers and 41 (68.3%) nonsmokers of tobacco. Significant correlations were obtained between the exhaled carbon monoxide levels of the smoker and nonsmoker groups (P < 0.05). Irrespective of the measures of smoking status, the frequency of detecting smokers was comparable to that of detecting nonsmokers (P = 0.756).

Conclusions

Similar to self-reports, the exhaled carbon monoxide measurement successfully distinguished smokers from nonsmokers. This allows healthcare providers and policy-makers to examine the effectiveness of tobacco cessation and prevention programmes.

Changes in fractional exhaled nitric oxide, exhaled carbon monoxide and pulmonary function during the acute attack, treatment and remission phases of pediatric asthma

BACKGROUND

The current study aimed to explore the value of fractional exhaled nitric oxide (FeNO), exhaled carbon monoxide (eCO), and pulmonary function in the management of asthmatic children.

METHODS

One hundred children diagnosed with asthma were selected as research subjects. Patients were divided into a 3-5-year-old group and a group with children 6 years and older. They were also grouped depending on whether they had asthma alone (A0 group) or whether their asthma was complicated with allergic rhinitis (A+AR group). The FeNO, eCO levels, and pulmonary function in the acute attack period were analyzed 1 month after treatment and clinical remission period.

RESULTS

Asthmatic children demonstrated greater pulmonary dysfunction and significantly higher FeNO and eCO during the acute attack phase compared to both one month after treatment and clinical remission. The remission phase was characterized by decreased levels of FeNO and eCO and improvement of pulmonary function. The eCO levels in children aged 3-5 years old, and both FeNO and eCO levels in children 6 years and older were statistically lower during remission regardless of whether the patients had asthma alone or asthma complicated with rhinitis. However, 10% of the 100 children in the clinical remission period still demonstrated mid to high levels of FeNO. The critical value of FeNO levels during the acute period in children 6 years and older with asthma and rhinitis was 34.5 ppb (AUROC 0.814, 95% CI: 0.684-0.944) with a sensitivity of 69.2% and specificity of 93.7%.

CONCLUSIONS

Dynamic monitoring of FeNO and eCO is an effective indicator of airway inflammation and thus represents an important clinical tool in assessing the severity of asthma in children.

Self-reported smoking status and exhaled carbon monoxide in secondary preventive follow-up after coronary heart events: Do our patients tell the truth?

INTRODUCTION

Smoking cessation reduces the risk of myocardial infarctions (MI) and death in patients with coronary heart disease. Smoking status is frequently assessed based on self-report. The aims of this study were to compare self-reported and objectively measured (exhaled carbon monoxide [eCO]) smoking status after MI, percutaneous coronary intervention (PCI), and coronary artery bypass grafting (CABG), and to assess whether assumed wrongly declared smoking cessation was associated to poorer achievement of other treatment targets for secondary prevention.

METHODS

This study was a sub-analysis from a randomized controlled trial at Sorlandet Hospital, Arendal, Norway, 2007-2022, including patients hospitalized due to MI or after scheduled PCI/CABG, and primarily aimed at comparing secondary preventive follow-up in the outpatient clinic versus primary healthcare. Participants were followed up after the index event through outpatient consultations. Smoking status was assessed by self-report and by eCO (Smokerlyzer, Bedfont, UK) with concentration values ≥6 ppm interpreted as suggesting smoking.

RESULTS

A total of 1540 participants aged 18-80 years were included in the main study. Self-reported smoking status and concomitant eCO measurement one year after the index event were available in 1291 (84%) participants. In all, Brussels, Belgium, from the 12th to the 13th of September 2024. The concentration of eCO was ≥6 ppm one year after the index event in 285 (22%) patients, and 72 (25%) of these patients reported non-smoking. Fewer patients with elevated eCO reporting non-smoking achieved the treatment target for blood pressure (<140/90 mmHg) in comparison to those reporting smoking (53% vs 68%, p=0.02). No differences for the other treatment targets for secondary prevention were found.

CONCLUSIONS

The study indicates a need for objective measures for smoking cessation both in clinical studies and in clinical practice, and may indicate a lack of truthfulness regarding smoking habits.

CLINICAL TRIAL REGISTRATION

The study is registered on the official website of ClinicalTrials.gov.

IDENTIFIER

ID NCT00679237.

Evaluation of Exhaled Carbon Monoxide Levels in Individuals Exposed to Passive Tobacco Smoke in Indoor and Outdoor Environments: How Far Can We Getaway Under the Same Roof?

INTRODUCTION

Besides direct exposure, indirect contact with tobacco smoke significantly contributes to numerous health issues. Unfortunately, people are unaware that the precautions taken in closed environments are inadequate to deal with this issue. We conducted this study to assess carbon monoxide (CO) levels of people exposed to tobacco smoke indoors and outdoors.

METHODS

Our study between May and June 2023 included individuals exposed to tobacco smoke indoors (n=100) and outdoors (n=100). Our control group included 100 people who had never been exposed to healthy tobacco smoke and agreed to participate in our research. The amount of CO exhaled was measured by observing how long people were in contact with tobacco smoke and how close they were to it. Questionnaires were asked of the study participants about the harms and awareness of tobacco smoke exposure.

RESULTS

Exhaled CO levels were 1.46 ± 0.1 ppm in people exposed to tobacco smoke indoors, 1.1± 0.03 ppm in people exposed to smoke outside, and 1.1± 0.02 ppm in the control group. The statistical analysis revealed that individuals exposed to tobacco smoke in the indoor environment had significantly higher exhaled CO levels than those in the outdoor and the control groups (p=0.006). In the correlation analysis of time and distance in the indoor environment with the exhaled CO level, there was no statistically significant difference between time and space (r= -0.168, p=0.09, r=0.09, p=0.37, respectively). While less than half of both groups were aware of second-hand tobacco smoke, individuals exposed to tobacco smoke in the outdoor environment were more familiar (p<0.001).

CONCLUSION

Despite the precautions, indoor tobacco smoke exposure is severe because of second- and third-hand smoke. Raising individual awareness and enhancing the steps should be our top concern to prevent future health problems.

Evaluation of the relationship between the level of addiction and exhaled carbon monoxide levels with QT dispersion in smokers

INTRODUCTION

Smoking increases the risk of arrhythmia. QT dispersion (QTd) is an important indicator for the determination of ventricular arrhythmia. In this study, we aimed to determine the arrhythmia risk by evaluating QTd in smokers and to assess the relationship between the level of nicotine addiction and carbon monoxide (CO) level in the expiratory air.

METHODS

This study was designed as a single-center, cross-sectional study. Among the chronic smokers referred to the Smoking Cessation Clinic of a tertiary hospital between October 2019 and January 2020, all those who had no risk factors for cardiac arrhythmias, except smoking, were included in the study. Sociodemographic data and smoking characteristics of the participants were collected and exhaled CO levels were measured. QT intervals were measured in all leads by using a 12-lead standard electrocardiogram (ECG), and heart rate corrected QT (QTc) intervals, QT dispersion (QTd), and corrected QT dispersion (QTcd) were calculated.

RESULTS

The mean age of the 250 patients was 37.2±9.3 years and the majority of patients (65%) were male. The mean amount of smoking was 25.74±16.03 packs/year and the mean value of CO was 12.36±7.06 ppm. The mean QTd was 23.83±13.12 ms, and the mean QTcd was 26.63±15.02 ms. A statistically significant relationship was found between QTd and QTcd and level of addiction, consumption of sticks/day and packs/year, and exhaled CO values (all p<0.001).

CONCLUSIONS

It was found that as the level of addiction, cigarette use amount, exhaled CO levels, and BMI increased in smokers, QT dispersion and arrhythmia risk increased.

The validity of self-reported smoking status on day of surgery in a mixed elective surgery population

Rates of misrepresenting smoking status on day of surgery varies with the clinical context. In perioperative smoking cessation trials, participants in the intervention group might be more likely to provide untruthful data about quitting when they have received substantial quit support but continued to smoke. The objective of this study was to determine misrepresentation rates of smoking status on day of surgery in mixed elective surgical populations, comparing groups offered or not offered additional cessation support. We undertook a post hoc analysis of data from three published randomised trials at a Melbourne public hospital that incorporated interventions during the wait-list period aimed at increasing smoking cessation. Participants were smokers (n = 1413) who were randomised to minimal cessation help at wait-listing (control group) or significant assistance, for example, mailed nicotine replacement (intervention group). Quit by day of surgery claims were verified by exhaled carbon monoxide (true cessation <8 parts per million). Verified cessation (>24 h) before surgery occurred in 161/1413 (11.4%) while 44/1413 (3.1%) misrepresented quitting. Continued smoking was in 1208/1413 (85.5%). Misrepresentations were higher in the intervention/offer of help groups (4.1%) than control groups (1.7%) (odds ratio (OR) 2.46, 95% confidence interval (CI) 1.17 to 5.63, P = 0.012). Offering cessation help increased quitting odds by 77%, (OR 1.77, 95% CI 1.24 to 2.52, P = 0.002). In contrast to other studies, we found group allocation in cessation trial settings had a significant effect on misrepresentation risk. The implication of this is that biochemical verification of quit status is essential in trial contexts for accurate data collection and to prevent misclassification bias.

Exhaled Carbon Monoxide Level and Practices among Tobacco and Nicotine Adult Users in Klang Valley, Malaysia

Tobacco and nicotine derivatives uses are multiple in nature. These include conventional cigarettes (CCs), heated tobacco products (HTPs), and electronic cigarettes (ECs). This study aims to determine the practices, nicotine dependency profile, association with exhaled carbon monoxide (eCO) level, and pulmonary function (PF) among adult product users and non-smokers. This cross-sectional study involved smokers, nicotine users, and non-smokers from two public health facilities in Kuala Lumpur from December 2021 to April 2022. Data on socio-demography, smoking profile, nicotine dependency level, anthropometry, eCO monitor, and spirometer measurements were recorded. Out of 657 respondents, 52.1% were non-smokers, 48.3% were CC only smokers, poly-users (PUs) (27.3%), EC-only users (20.9%), and HTP-only users (3.5%). EC use was prevalent among the younger aged, tertiary educated, and females; HTP use was prevalent among those of an older age and CC users was common among lower educated males. The highest median eCO (in ppm) seen were as follows: in CC users only (13.00), PUs (7.00), EC users (2.00), HTP users (2.00), and the least was observed among non-smokers (1.00), which is significantly different across the groups (p <0.001). Comparison of practice between the different product users showed significant differences in age of product initiation (p <0.001, youngest in CC users in PUs), duration of product use (p <0.001, longest in exclusive CC users), cost per month (p <0.001, highest in exclusive HTP users) and attempt to quit product (p <0.001, CC use in PUs had the highest attempt to quit), while there is no significant difference in Fagerström score across the groups. Among EC users, 68.2% successfully switched from smoking CCs to ECs. The findings suggest that EC and HTP users are exhaling less CO. The use of these products in a targeted approach may manage nicotine addiction. Switching practice was higher among current EC users (from using CCs), hence emphasizing the need of switching encouragement and total nicotine abstinence later on. Lower eCO levels in the PU group, (as compared to CC-only users) and high quit attempt rate among in CC use in PUs may indicate attempt of PUs in reducing CC use through alternative modalities such as ECs and HTPs.