Trial Outcomes & Findings for Effects of E-Cigarette Nicotine Content in Smokers (Nicotine Flux Study) (NCT NCT04332926)

Last Updated: 2025-02-13

Results Overview

This is now a single-arm parallel study design. The main outcome of interest in the CP-PRT is the relative reinforcing value - defined as how hard a participant is willing to work for the session product compared to their own brand cigarette. The breakpoint, or highest trial number that a participant completed for a puff of the session-specific product will be used as the measure of relative reinforcing value.

Recruitment status

COMPLETED

Study phase

Target enrollment

44 participants

Primary outcome timeframe

The CP-PRT is completed once per study session (except it is not completed in the 5th, own brand session), at 185 minutes into the session.

Results posted on

2025-02-13

Participant Flow

Participant milestones

Participant milestones
Measure	Overall Enrollment When I try to add the individual numbers for the different procedures, it confuses the system since it looks like each procedure is a seperate arm. For feasibility issues the study design was altered from a crossover study to a single-arm parallel one. So for this arm, Tobacco product administration and assessment: 4 sample puffs, followed by a 60 minute rest period, hypothetical drug purchase tasks, followed by progressive ratio tasks (single product and two products, with 60 minute rest in between) where participants work to earn puffs of tobacco products; preceded and followed by physiological and subjective assessment
Overall Study STARTED	44
Overall Study Active Comparator: Own Brand Cig	32
Overall Study Experimental: ECIG 30 W, 0 mg/ml Nic	35
Overall Study Experimental: ECIG 30 W, 8 mg/ml Nic	34
Overall Study Experimental: ECIG 30 W, 15 mg/ml Nic	34
Overall Study Experimental: ECIG 30 W, 30 mg/ml Nic	36
Overall Study COMPLETED	32
Overall Study NOT COMPLETED	12

Reasons for withdrawal

Reasons for withdrawal
Measure	Overall Enrollment When I try to add the individual numbers for the different procedures, it confuses the system since it looks like each procedure is a seperate arm. For feasibility issues the study design was altered from a crossover study to a single-arm parallel one. So for this arm, Tobacco product administration and assessment: 4 sample puffs, followed by a 60 minute rest period, hypothetical drug purchase tasks, followed by progressive ratio tasks (single product and two products, with 60 minute rest in between) where participants work to earn puffs of tobacco products; preceded and followed by physiological and subjective assessment
Overall Study Withdrawal by Subject	6
Overall Study Physician Decision	6

Baseline Characteristics

Effects of E-Cigarette Nicotine Content in Smokers (Nicotine Flux Study)

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Experimental n=44 Participants Tobacco product administration and assessment: 4 sample puffs, followed by a 60 minute rest period, hypothetical drug purchase tasks, followed by progressive ratio tasks (single product and two products, with 60 minute rest in between) where participants work to earn puffs of tobacco products; preceded and followed by physiological and subjective assessment
Age, Continuous	37.61 years STANDARD_DEVIATION 9.08 • n=99 Participants
Sex: Female, Male Female	13 Participants n=99 Participants
Sex: Female, Male Male	31 Participants n=99 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	2 Participants n=99 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	41 Participants n=99 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	1 Participants n=99 Participants
Race (NIH/OMB) American Indian or Alaska Native	1 Participants n=99 Participants
Race (NIH/OMB) Asian	0 Participants n=99 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=99 Participants
Race (NIH/OMB) Black or African American	23 Participants n=99 Participants
Race (NIH/OMB) White	14 Participants n=99 Participants
Race (NIH/OMB) More than one race	3 Participants n=99 Participants
Race (NIH/OMB) Unknown or Not Reported	3 Participants n=99 Participants
Region of Enrollment United States	44 participants n=99 Participants

PRIMARY outcome

Timeframe: The CP-PRT is completed once per study session (except it is not completed in the 5th, own brand session), at 185 minutes into the session.

Population: The study morphed from a cross-over study into a single-arm study due to feasibility issues. Instead of different arms completing the interventions in a different order, all of the subjects were moved into one arm and completed the interventions in the same order.

Outcome measures

Outcome measures
Measure	Experimental n=32 Participants Tobacco product administration and assessment: 4 sample puffs, followed by a 60 minute rest period, hypothetical drug purchase tasks, followed by progressive ratio tasks (single product and two products, with 60 minute rest in between) where participants work to earn puffs of tobacco products; preceded and followed by physiological and subjective assessment
Effort for Product Puffs With Cross Product Progressive Ratio Task (CP-PRT) ECIG 30 Watts, 0 mg/ml nicotine	6.30 Breakpoint (highest trial completed) Standard Deviation 2.83
Effort for Product Puffs With Cross Product Progressive Ratio Task (CP-PRT) ECIG 30 Watts, 8 mg/ml nicotine	6.38 Breakpoint (highest trial completed) Standard Deviation 2.94
Effort for Product Puffs With Cross Product Progressive Ratio Task (CP-PRT) ECIG 30 Watts, 15 mg/ml nicotine	6.34 Breakpoint (highest trial completed) Standard Deviation 2.70
Effort for Product Puffs With Cross Product Progressive Ratio Task (CP-PRT) ECIG 30 Watts, 30 mg/ml nicotine	5.94 Breakpoint (highest trial completed) Standard Deviation 2.93

PRIMARY outcome

Timeframe: Each DPT will be completed once per study session, about 75 minutes into the session. The results will reported in US dollars ($).

The DPTs will yield measures of willingness to pay (demand) for session-specific tobacco products. Choices made during this task are not reinforced during the session. Using the DPT, participants estimate the number of session-specific product puffs they would take across increasing prices per puff. DPT demand will be characterized by the Breakpoint (BP); i.e., the highest price per puff at which participants indicate they would stop using the session-specific product rather than incur the cost.

Outcome measures

Outcome measures
Measure	Experimental n=32 Participants Tobacco product administration and assessment: 4 sample puffs, followed by a 60 minute rest period, hypothetical drug purchase tasks, followed by progressive ratio tasks (single product and two products, with 60 minute rest in between) where participants work to earn puffs of tobacco products; preceded and followed by physiological and subjective assessment
Breakpoint of Drug Purchase Task (DPT) ECIG 30 Watts, 8 mg/ml nicotine	0.96 US dollars ($) Standard Deviation 1.78
Breakpoint of Drug Purchase Task (DPT) Own Brand Cigarette	1.23 US dollars ($) Standard Deviation 2.10
Breakpoint of Drug Purchase Task (DPT) ECIG 30 Watts, 0 mg/ml nicotine	0.54 US dollars ($) Standard Deviation 0.90
Breakpoint of Drug Purchase Task (DPT) ECIG 30 Watts, 15 mg/ml nicotine	0.43 US dollars ($) Standard Deviation 0.77
Breakpoint of Drug Purchase Task (DPT) ECIG 30 Watts, 30 mg/ml nicotine	0.49 US dollars ($) Standard Deviation 1.01

PRIMARY outcome

Timeframe: The PRT is completed once per study session, at 85 minutes into the session.

The PRT will yield a measure of willingness to work for session-specific tobacco products (via number of times a space bar is pressed to earn puffs) through the outcome measure: mean number of puffs self-administrated. The outcome measure of interest is the total number of puffs self-administered.

Outcome measures

Outcome measures
Measure	Experimental n=32 Participants Tobacco product administration and assessment: 4 sample puffs, followed by a 60 minute rest period, hypothetical drug purchase tasks, followed by progressive ratio tasks (single product and two products, with 60 minute rest in between) where participants work to earn puffs of tobacco products; preceded and followed by physiological and subjective assessment
Effort for Product Puffs With Progressive Ratio Task (PRT) ECIG 30 Watts, 0 mg/ml nicotine	7.69 Number of puffs Standard Deviation 3.51
Effort for Product Puffs With Progressive Ratio Task (PRT) Own Brand Cigarette	9.06 Number of puffs Standard Deviation 2.73
Effort for Product Puffs With Progressive Ratio Task (PRT) ECIG 30 Watts, 8 mg/ml nicotine	7.88 Number of puffs Standard Deviation 3.42
Effort for Product Puffs With Progressive Ratio Task (PRT) ECIG 30 Watts, 15 mg/ml nicotine	7.31 Number of puffs Standard Deviation 3.89
Effort for Product Puffs With Progressive Ratio Task (PRT) ECIG 30 Watts, 30 mg/ml nicotine	6.34 Number of puffs Standard Deviation 4.37

Adverse Events

Experimental

Serious events: 1 serious events

Other events: 3 other events

Deaths: 0 deaths

Serious adverse events

Serious adverse events
Measure	Experimental n=44 participants at risk The study was originally organized as a cross-over study but due to feasibility circumstances, the study team determined that it was more important to preserve the subject enrollment numbers and complete the study in the most efficient manner for the enrolled subjects. So this became a single-arm parallel study. The study involved Tobacco product administration and assessment: 1) Effort for Product Puffs With Cross Product Progressive Ratio Task (CP-PRT), 2) Breakpoint of Drug Purchase Task (DPT), and 3) Effort for Product Puffs With Progressive Ratio Task (PRT) The individual interventions are listed in the milestones section.
Surgical and medical procedures Surgical and medical procedures: unrelated hysterectomy	2.3% 1/44 • Number of events 1 • Data were collected during laboratory visits, approximately over 3 weeks; no follow up adverse event data collection occurred. Non-systematic. Questionnaire assessed at the beginning of each laboratory session, participant self-report. For adverse events that happened outside of the laboratory, no experimental condition is applicable. For adverse events that happened within the laboratory (e.g., during an experimental session), events are reported separately for each relevant experimental condition.

Other adverse events

Other adverse events
Measure	Experimental n=44 participants at risk The study was originally organized as a cross-over study but due to feasibility circumstances, the study team determined that it was more important to preserve the subject enrollment numbers and complete the study in the most efficient manner for the enrolled subjects. So this became a single-arm parallel study. The study involved Tobacco product administration and assessment: 1) Effort for Product Puffs With Cross Product Progressive Ratio Task (CP-PRT), 2) Breakpoint of Drug Purchase Task (DPT), and 3) Effort for Product Puffs With Progressive Ratio Task (PRT) The individual interventions are listed in the milestones section.
Blood and lymphatic system disorders Elevated Blood Pressure, ECIG 30 W, 30 mg/ml nicotine condition	6.8% 3/44 • Number of events 3 • Data were collected during laboratory visits, approximately over 3 weeks; no follow up adverse event data collection occurred. Non-systematic. Questionnaire assessed at the beginning of each laboratory session, participant self-report. For adverse events that happened outside of the laboratory, no experimental condition is applicable. For adverse events that happened within the laboratory (e.g., during an experimental session), events are reported separately for each relevant experimental condition.

Additional Information

Caroline Cobb, PhD, PI

Virginia Commonwealth University

Phone: 804-828-8687

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place