Cigarette Smoking-Related Carcinoma
Conditions
Brief summary
This clinical trial studies the effect of free-base compared with nicotine salt based e-liquids on electronic cigarette (EC) puffing behavior, abuse liability, and deposition and absorption of nicotine in the respiratory tract and rate of uptake in the brain in current EC smokers. The results from this study may provide much needed scientific information to public health officials and regulators.
Detailed description
PRIMARY OBJECTIVES: I. To examine the influence of nicotine form on puffing behavior and abuse liability. II. To evaluate the influence of nicotine form and concentration on nicotine distribution in the brain and respiratory tract. OUTLINE: VISIT 1: Patients sample 4-liquids to determine whether they can vape the unflavored e-liquid without coughing Patients are randomized to 1 of 2 arms. ARM I: VISIT 2: Patients receive 1 puff of tobacco flavored or unflavored protonated e-liquid and undergo 0-15 minutes (min) head and 5 min chest positron emission tomography (PET)/computed tomography (CT) and then 0-15 min chest and 5 min head PET/CT. About 2 hours post initial PET/CT, patients receive a second puff of tobacco flavored or unflavored protonated e-liquid and undergo 0-15 min chest and 5 min head PET/CT and then 0-15 min head and 5 min chest PET/CT. VISIT 3: Patients receive 1 puff of tobacco flavored or unflavored unprotonated e-liquid and undergo 0-15 min head and 5 min chest PET/CT and then 0-15 min chest and 5 min head PET/CT. About 2 hours post initial PET/CT, patients receive a second puff of tobacco flavored or unflavored unprotonated e-liquid and undergo 0-15 min chest and 5 min head PET/CT and then 0-15 min head and 5 min chest ARM II: VISIT 2: Patients receive 1 puff of tobacco flavored or unflavored unprotonated e-liquid and undergo 0-15 min head and 5 min chest PET/CT and then 0-15 min chest and 5 min head PET/CT. About 2 hours post initial PET/CT, patients receive a second puff of tobacco flavored or unflavored unprotonated e-liquid and undergo 0-15 min chest and 5 min head PET/CT and then 0-15 min head and 5 min chest. VISIT 3: Patients receive 1 puff of tobacco flavored or unflavored protonated e-liquid and undergo 0-15 min head and 5 min chest PET/CT and then 0-15 min chest and 5 min head PET/CT. About 2 hours post initial PET/CT, patients receive a second puff of tobacco flavored or unflavored protonated e-liquid and undergo 0-15 min chest and 5 min head PET/CT and then 0-15 min head and 5 min chest PET/CT.
Interventions
BEHAVIORALCigarette Smoking
Receive 1 puff of tobacco flavored protonated e-liquid
PROCEDUREComputed Tomography
Undergo PET/CT
PROCEDUREPositron Emission Tomography
Undergo PET/CT
OTHERQuestionnaire Administration
Ancillary studies
Sponsors
Ohio State University Comprehensive Cancer Center
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
PREVENTION
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
21 Years to 50 Years
Healthy volunteers
No
Inclusion criteria
* A current exclusive e-cigarette user (\>= 1 vaping bout per day) for at least the past 6 months (confirmed by NicAlert saliva testing strip) * Between 21-50 years old * Willing to provide informed consent and abstain from all tobacco and nicotine use for at least 12 hours prior to visits 2 and 3 * Willing to participate in 3 laboratory visits * Read and speak English * If utilizing study provided rideshare services, will need to live within 20 miles of Wake Forest University
Exclusion criteria
* Self-reported diagnosis of lung disease including asthma, cystic fibrosis, or chronic obstructive pulmonary disease * Unstable or significant psychiatric conditions (past and stable conditions will be allowed) * History of cardiac event or distress within the past 3 months * Currently pregnant (as indicated by urine pregnancy test at the start of each laboratory visit), planning to become pregnant, or breastfeeding (women only) * Use of other tobacco products (e.g., cigarette, cigar, etc.) \> 5 days in the past month * Currently engaging in a tobacco product cessation attempt
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| PET/CT Imaging of the Head | 1.5 hours | Evaluate effect of nicotine form (free-base vs nicotine salt base) on nicotine absorption and distribution in the brain with total absorbed dose (TAD) of \[11C\]nicotine. |
| PET/CT Imaging of the Chest | 1.5 hours | Evaluate effect of nicotine form (free-base vs nicotine salt base) on nicotine absorption and distribution in the respiratory tract with total absorbed dose (TAD) of \[11C\]nicotine. |
| Puff Volume (mL) | approx. 30 minutes | Puffing topography data was captured by the study e-cigarette to determine the puff volume. |
| Puff Duration (s) | approx. 30 minutes | Puffing topography data was captured by the study e-cigarette to determine the puff duration. |
| Age of First Tobacco Use | approx. 5 minutes | Age of first use will be assessed using the tobacco use history questionnaire. |
| Years of Tobacco Use | approx. 5 minutes | Years of tobacco use will be assessed using the tobacco use history questionnaire. |
| Years of Regular Use of Nicotine/Tobacco Products | approx. 5 minutes | Years of regular use of nicotine/tobacco products will be assessed using the tobacco history questionnaire |
| Past 30 Day Use of Nicotine/Tobacco Products | approx. 5 minutes | Days used in the past 30 days of nicotine/tobacco products including cigars, cigarillos, little cigars, pipe tobacco, chewing tobacco, snuff, snus, EC/vape/mod/APV/e-hookah, and hookah tobacco. |
| Modified Cigarette Evaluation Questionnaire (mCEQ) | approx. 5 minutes | 12-item modified Cigarette Evaluation Questionnaire (mCEQ) completed following e-cigarette self-administration to assess subjective responses. The 12-item mCEQ includes five subscales: Smoking Satisfaction, Psychological Reward, Aversion, Enjoyment of Respiratory Tract Sensations, and Craving Reduction, with items rated from 0 (not at all) to 6 (extremely likely). Scores for each subscale are calculated as the mean of the individual item responses or the single item. Higher scores indicate greater intensity on that scale. |
| Drug Effects Liking Questionnaire (DEQ) | approx. 5 minutes | An adapted version of the Drug Effects/Liking Questionnaire will assess the desire and liking of the study products. Five visual analog scale items ranging from 0 (not at all) to 100 (extremely) assessed wanting to vape the product again, liking the product, enjoying the product, finding the product pleasurable and satisfying. Higher scores indicate greater liking. |
| Modified Tiffany-Drobes Questionnaire of Smoking Urges: Brief Form (QSU) | aprox. 5 minutes | Urges/craving will be measured using a modified version of the Tiffany-Drobes Questionnaire of Smoking Urges: Brief Form. This is a 10-item measure where participants rate e-cigarette smoking-related items (All I want right now is an e-cigarette) on a 7-point Likert scale ranging from 1 (strongly disagree) to 7 (strongly agree). Similar to previous studies, we will collapse the items into two previously identified factors (Factor 1: strong desire and intention to smoke an e-cigarette; Factor 2: anticipation of relief from withdrawal symptoms). Scores are calculated by summing the items and range from 5 to 35 with higher scores indicating greater craving to vape. |
| Minnesota Nicotine Withdrawal Scale | approx. 5 minutes | Nicotine withdrawal will be assessed using the empirically validated 15-item version of the Minnesota Nicotine Withdrawal Scale (MNWS). Items were rated on a 5-point scale from 0 (none) to 4 (severe). This measure assesses smoking craving, anger/irritability, anxiety, depressed mood, restlessness/difficulty concentrating, increased appetite, sleep problems, and somatic symptoms (nausea, constipation, sore throat, dizziness, coughing). MNWS is the sum of 8 items with scores ranging from 0 to 32 and MNWS Craving is a single item with scores ranging from 0 to 4, higher scores indicate a greater craving. |
| Exhaled Breath Carbon Monoxide (CO) | approx. 5 minutes | Exhaled breath carbon monoxide was collected before each scan with a handheld electrochemical device. |
Countries
United States
Participant flow
Pre-assignment details
1 participant was consented and enrolled in the study but found to be ineligible during visit 1, prior to randomization.
Participants by arm
| Arm | Count |
|---|---|
| Arm I (Protonated E-liquid, Unprotonated E-liquid) Visit 2: Patients sample protonated e-liquid Visit 3: Patients sample unprotonated e-liquid | 12 |
| Arm II (Unprotonated E-liquid, Protonated E-liquid) Visit 2: Patients sample unprotonated e-liquid Visit 3: Patients sample protonated e-liquid | 8 |
| Total | 20 |
Baseline characteristics
| Characteristic | Arm II (Unprotonated E-liquid, Protonated E-liquid) | Total | Arm I (Protonated E-liquid, Unprotonated E-liquid) |
|---|---|---|---|
| Age, Continuous | 31.50 years STANDARD_DEVIATION 7.27 | 33.10 years STANDARD_DEVIATION 7.58 | 34.17 years STANDARD_DEVIATION 7.91 |
| Race/Ethnicity, Customized American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants |
| Race/Ethnicity, Customized Asian | 0 Participants | 0 Participants | 0 Participants |
| Race/Ethnicity, Customized Black or African American | 0 Participants | 0 Participants | 0 Participants |
| Race/Ethnicity, Customized Middle Eastern | 1 Participants | 1 Participants | 0 Participants |
| Race/Ethnicity, Customized More than one race | 1 Participants | 1 Participants | 0 Participants |
| Race/Ethnicity, Customized Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants |
| Race/Ethnicity, Customized White | 6 Participants | 18 Participants | 12 Participants |
| Sex: Female, Male Female | 4 Participants | 11 Participants | 7 Participants |
| Sex: Female, Male Male | 4 Participants | 9 Participants | 5 Participants |
| Years of regular e-cigarette use | 4.13 years STANDARD_DEVIATION 2.95 | 3.85 years STANDARD_DEVIATION 2.81 | 3.67 years STANDARD_DEVIATION 2.84 |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 20 | 0 / 20 |
| other Total, other adverse events | 2 / 20 | 0 / 20 |
| serious Total, serious adverse events | 0 / 20 | 0 / 20 |
Outcome results
Primary
Age of First Tobacco Use
Age of first use will be assessed using the tobacco use history questionnaire.
Time frame: approx. 5 minutes
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Protonated E-liquid | Age of First Tobacco Use | 14.58 years | Standard Deviation 2.02 |
| Unprotonated E-liquid | Age of First Tobacco Use | 14.63 years | Standard Deviation 1.6 |
Primary
Drug Effects Liking Questionnaire (DEQ)
An adapted version of the Drug Effects/Liking Questionnaire will assess the desire and liking of the study products. Five visual analog scale items ranging from 0 (not at all) to 100 (extremely) assessed wanting to vape the product again, liking the product, enjoying the product, finding the product pleasurable and satisfying. Higher scores indicate greater liking.
Time frame: approx. 5 minutes
Population: The drug effects liking questionnaire was only administered during the second study visit
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Protonated E-liquid | Drug Effects Liking Questionnaire (DEQ) | Like | 51.25 units on a scale | Standard Deviation 32.76 |
| Protonated E-liquid | Drug Effects Liking Questionnaire (DEQ) | Pleasurable | 56.08 units on a scale | Standard Deviation 32.42 |
| Protonated E-liquid | Drug Effects Liking Questionnaire (DEQ) | Enjoy | 57.25 units on a scale | Standard Deviation 30.63 |
| Protonated E-liquid | Drug Effects Liking Questionnaire (DEQ) | Satisfying | 60.33 units on a scale | Standard Deviation 32.66 |
| Protonated E-liquid | Drug Effects Liking Questionnaire (DEQ) | Want | 60.08 units on a scale | Standard Deviation 29.44 |
| Unprotonated E-liquid | Drug Effects Liking Questionnaire (DEQ) | Satisfying | 35.63 units on a scale | Standard Deviation 28.54 |
| Unprotonated E-liquid | Drug Effects Liking Questionnaire (DEQ) | Want | 42.88 units on a scale | Standard Deviation 26.69 |
| Unprotonated E-liquid | Drug Effects Liking Questionnaire (DEQ) | Like | 32.50 units on a scale | Standard Deviation 25.93 |
| Unprotonated E-liquid | Drug Effects Liking Questionnaire (DEQ) | Enjoy | 31.88 units on a scale | Standard Deviation 26.38 |
| Unprotonated E-liquid | Drug Effects Liking Questionnaire (DEQ) | Pleasurable | 29.13 units on a scale | Standard Deviation 26.94 |
Primary
Exhaled Breath Carbon Monoxide (CO)
Exhaled breath carbon monoxide was collected before each scan with a handheld electrochemical device.
Time frame: approx. 5 minutes
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Protonated E-liquid | Exhaled Breath Carbon Monoxide (CO) | 2.45 ppm | Standard Deviation 1.79 |
| Unprotonated E-liquid | Exhaled Breath Carbon Monoxide (CO) | 2.80 ppm | Standard Deviation 2.31 |
Primary
Minnesota Nicotine Withdrawal Scale
Nicotine withdrawal will be assessed using the empirically validated 15-item version of the Minnesota Nicotine Withdrawal Scale (MNWS). Items were rated on a 5-point scale from 0 (none) to 4 (severe). This measure assesses smoking craving, anger/irritability, anxiety, depressed mood, restlessness/difficulty concentrating, increased appetite, sleep problems, and somatic symptoms (nausea, constipation, sore throat, dizziness, coughing). MNWS is the sum of 8 items with scores ranging from 0 to 32 and MNWS Craving is a single item with scores ranging from 0 to 4, higher scores indicate a greater craving.
Time frame: approx. 5 minutes
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Protonated E-liquid | Minnesota Nicotine Withdrawal Scale | MNWS | 9.50 score on a scale | Standard Deviation 7.38 |
| Protonated E-liquid | Minnesota Nicotine Withdrawal Scale | MNWS Craving | 2.60 score on a scale | Standard Deviation 0.94 |
| Unprotonated E-liquid | Minnesota Nicotine Withdrawal Scale | MNWS | 9.10 score on a scale | Standard Deviation 6.32 |
| Unprotonated E-liquid | Minnesota Nicotine Withdrawal Scale | MNWS Craving | 2.70 score on a scale | Standard Deviation 1.17 |
Primary
Modified Cigarette Evaluation Questionnaire (mCEQ)
12-item modified Cigarette Evaluation Questionnaire (mCEQ) completed following e-cigarette self-administration to assess subjective responses. The 12-item mCEQ includes five subscales: Smoking Satisfaction, Psychological Reward, Aversion, Enjoyment of Respiratory Tract Sensations, and Craving Reduction, with items rated from 0 (not at all) to 6 (extremely likely). Scores for each subscale are calculated as the mean of the individual item responses or the single item. Higher scores indicate greater intensity on that scale.
Time frame: approx. 5 minutes
Population: mCEQ was only evaluated during the second study visit
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Protonated E-liquid | Modified Cigarette Evaluation Questionnaire (mCEQ) | Psychological Reward | 2.17 Score on a scale | Standard Deviation 1.27 |
| Protonated E-liquid | Modified Cigarette Evaluation Questionnaire (mCEQ) | Enjoyment of Respiratory Tract Sensations | 2.42 Score on a scale | Standard Deviation 1.31 |
| Protonated E-liquid | Modified Cigarette Evaluation Questionnaire (mCEQ) | Aversion | 0.88 Score on a scale | Standard Deviation 1.05 |
| Protonated E-liquid | Modified Cigarette Evaluation Questionnaire (mCEQ) | Craving Reduction | 3.67 Score on a scale | Standard Deviation 2.1 |
| Protonated E-liquid | Modified Cigarette Evaluation Questionnaire (mCEQ) | Satisfaction | 2.28 Score on a scale | Standard Deviation 1.31 |
| Unprotonated E-liquid | Modified Cigarette Evaluation Questionnaire (mCEQ) | Craving Reduction | 3.25 Score on a scale | Standard Deviation 1.83 |
| Unprotonated E-liquid | Modified Cigarette Evaluation Questionnaire (mCEQ) | Satisfaction | 1.42 Score on a scale | Standard Deviation 0.92 |
| Unprotonated E-liquid | Modified Cigarette Evaluation Questionnaire (mCEQ) | Psychological Reward | 1.38 Score on a scale | Standard Deviation 0.93 |
| Unprotonated E-liquid | Modified Cigarette Evaluation Questionnaire (mCEQ) | Aversion | 0.94 Score on a scale | Standard Deviation 1.47 |
| Unprotonated E-liquid | Modified Cigarette Evaluation Questionnaire (mCEQ) | Enjoyment of Respiratory Tract Sensations | 1.25 Score on a scale | Standard Deviation 1.16 |
Primary
Modified Tiffany-Drobes Questionnaire of Smoking Urges: Brief Form (QSU)
Urges/craving will be measured using a modified version of the Tiffany-Drobes Questionnaire of Smoking Urges: Brief Form. This is a 10-item measure where participants rate e-cigarette smoking-related items (All I want right now is an e-cigarette) on a 7-point Likert scale ranging from 1 (strongly disagree) to 7 (strongly agree). Similar to previous studies, we will collapse the items into two previously identified factors (Factor 1: strong desire and intention to smoke an e-cigarette; Factor 2: anticipation of relief from withdrawal symptoms). Scores are calculated by summing the items and range from 5 to 35 with higher scores indicating greater craving to vape.
Time frame: aprox. 5 minutes
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Protonated E-liquid | Modified Tiffany-Drobes Questionnaire of Smoking Urges: Brief Form (QSU) | Desire | 29.45 Score on a scale | Standard Deviation 6.83 |
| Protonated E-liquid | Modified Tiffany-Drobes Questionnaire of Smoking Urges: Brief Form (QSU) | Relief | 16.35 Score on a scale | Standard Deviation 8.01 |
| Unprotonated E-liquid | Modified Tiffany-Drobes Questionnaire of Smoking Urges: Brief Form (QSU) | Desire | 30.15 Score on a scale | Standard Deviation 5.82 |
| Unprotonated E-liquid | Modified Tiffany-Drobes Questionnaire of Smoking Urges: Brief Form (QSU) | Relief | 17.40 Score on a scale | Standard Deviation 9.38 |
Primary
Past 30 Day Use of Nicotine/Tobacco Products
Days used in the past 30 days of nicotine/tobacco products including cigars, cigarillos, little cigars, pipe tobacco, chewing tobacco, snuff, snus, EC/vape/mod/APV/e-hookah, and hookah tobacco.
Time frame: approx. 5 minutes
Population: 2 participants in Arm I declined to provide a response for the number of days they have used cigarettes in the past 30 days.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Protonated E-liquid | Past 30 Day Use of Nicotine/Tobacco Products | Pipes | 0 days | Standard Deviation 0 |
| Protonated E-liquid | Past 30 Day Use of Nicotine/Tobacco Products | e-cigarettes | 29.83 days | Standard Deviation 0.58 |
| Protonated E-liquid | Past 30 Day Use of Nicotine/Tobacco Products | Cigarillos | 0 days | Standard Deviation 0 |
| Protonated E-liquid | Past 30 Day Use of Nicotine/Tobacco Products | Smokeless Tobacco | 0 days | Standard Deviation 0 |
| Protonated E-liquid | Past 30 Day Use of Nicotine/Tobacco Products | Cigars | 0 days | Standard Deviation 0 |
| Protonated E-liquid | Past 30 Day Use of Nicotine/Tobacco Products | Snus | 0 days | Standard Deviation 0 |
| Protonated E-liquid | Past 30 Day Use of Nicotine/Tobacco Products | Little Cigars | 0 days | Standard Deviation 0 |
| Protonated E-liquid | Past 30 Day Use of Nicotine/Tobacco Products | Hookah | 0.17 days | Standard Deviation 0.58 |
| Protonated E-liquid | Past 30 Day Use of Nicotine/Tobacco Products | Cigarettes | 0 days | Standard Deviation 0 |
| Unprotonated E-liquid | Past 30 Day Use of Nicotine/Tobacco Products | Hookah | 0 days | Standard Deviation 0 |
| Unprotonated E-liquid | Past 30 Day Use of Nicotine/Tobacco Products | Cigarettes | 0.75 days | Standard Deviation 2.12 |
| Unprotonated E-liquid | Past 30 Day Use of Nicotine/Tobacco Products | Pipes | 0 days | Standard Deviation 0 |
| Unprotonated E-liquid | Past 30 Day Use of Nicotine/Tobacco Products | Cigars | 0 days | Standard Deviation 0 |
| Unprotonated E-liquid | Past 30 Day Use of Nicotine/Tobacco Products | Cigarillos | 0 days | Standard Deviation 0 |
| Unprotonated E-liquid | Past 30 Day Use of Nicotine/Tobacco Products | Little Cigars | 0 days | Standard Deviation 0 |
| Unprotonated E-liquid | Past 30 Day Use of Nicotine/Tobacco Products | e-cigarettes | 30.00 days | Standard Deviation 0 |
| Unprotonated E-liquid | Past 30 Day Use of Nicotine/Tobacco Products | Smokeless Tobacco | 0 days | Standard Deviation 0 |
| Unprotonated E-liquid | Past 30 Day Use of Nicotine/Tobacco Products | Snus | 0 days | Standard Deviation 0 |
Primary
PET/CT Imaging of the Chest
Evaluate effect of nicotine form (free-base vs nicotine salt base) on nicotine absorption and distribution in the respiratory tract with total absorbed dose (TAD) of \[11C\]nicotine.
Time frame: 1.5 hours
Population: Scan data from 3 participants was insufficient for calculating TAD and are not included in the statistics presented here, these participants were used for protocol optimizations.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Protonated E-liquid | PET/CT Imaging of the Chest | Upper Respiratory Tract | 6.18 %TAD/kg | Standard Deviation 2.17 |
| Protonated E-liquid | PET/CT Imaging of the Chest | Lower Respiratory Tract | 10.35 %TAD/kg | Standard Deviation 3.49 |
| Unprotonated E-liquid | PET/CT Imaging of the Chest | Upper Respiratory Tract | 11.62 %TAD/kg | Standard Deviation 3.17 |
| Unprotonated E-liquid | PET/CT Imaging of the Chest | Lower Respiratory Tract | 5.53 %TAD/kg | Standard Deviation 0.81 |
Primary
PET/CT Imaging of the Head
Evaluate effect of nicotine form (free-base vs nicotine salt base) on nicotine absorption and distribution in the brain with total absorbed dose (TAD) of \[11C\]nicotine.
Time frame: 1.5 hours
Population: Scan data from 3 participants was insufficient for calculating TAD and are not included in the statistics presented here, these participants were used for protocol optimizations.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Protonated E-liquid | PET/CT Imaging of the Head | 2.81 %TAD/kg | Standard Deviation 0.92 |
| Unprotonated E-liquid | PET/CT Imaging of the Head | 2.40 %TAD/kg | Standard Deviation 0.62 |
Primary
Puff Duration (s)
Puffing topography data was captured by the study e-cigarette to determine the puff duration.
Time frame: approx. 30 minutes
Population: Puffing topography was not able to be recorded for 2 participants while sampling the Protonated e-liquid and 1 participant while sampling the Unprotonated e-liquid.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Protonated E-liquid | Puff Duration (s) | 2.87 seconds | Standard Deviation 1.43 |
| Unprotonated E-liquid | Puff Duration (s) | 2.82 seconds | Standard Deviation 1.61 |
Primary
Puff Volume (mL)
Puffing topography data was captured by the study e-cigarette to determine the puff volume.
Time frame: approx. 30 minutes
Population: Puffing topography was not able to be recorded for 2 participants while sampling the Protonated e-liquid and 1 participant while sampling the Unprotonated e-liquid.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Protonated E-liquid | Puff Volume (mL) | 79.35 mL | Standard Deviation 72.75 |
| Unprotonated E-liquid | Puff Volume (mL) | 73.76 mL | Standard Deviation 70.82 |
Primary
Years of Regular Use of Nicotine/Tobacco Products
Years of regular use of nicotine/tobacco products will be assessed using the tobacco history questionnaire
Time frame: approx. 5 minutes
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Protonated E-liquid | Years of Regular Use of Nicotine/Tobacco Products | 16.83 years | Standard Deviation 8.99 |
| Unprotonated E-liquid | Years of Regular Use of Nicotine/Tobacco Products | 15.13 years | Standard Deviation 6.9 |
Primary
Years of Tobacco Use
Years of tobacco use will be assessed using the tobacco use history questionnaire.
Time frame: approx. 5 minutes
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Protonated E-liquid | Years of Tobacco Use | 19.58 years | Standard Deviation 8.85 |
| Unprotonated E-liquid | Years of Tobacco Use | 16.88 years | Standard Deviation 6.75 |