Table 1.
Study design.
Fig 1.
Exemplar wPUMTM monitor calibration data obtained from the PESTM-1 calibration system.
Shown are the pre-deployment week-1 (20160720), mid-week-1 (20160725), pre-deployment week-2 (20160727), and mid-week-2 (20160801) calibration results for wPUMTM monitor 3 used by participant 3. These calibration data document wPUMTM monitor-specific performance and the potential impact of monitor contamination during natural use monitoring. Effects are mitigated by pre- and post- calibration protocols and TAPTM program signal processing algorithms. Underlying data is available in S1, S2, S3, S4 Datasets.
Fig 2.
Exemplar topography and consumption behavior for a single vaping session.
Shown is an example resulting from phase 1 of the analysis. The TAPTM program converts raw noisy monitoring data (top panel) into discrete identifiable puffs with known flow rate (middle panel). Cumulative session volume (bottom panel) is determined by summing the individual puff volumes. Phase 1 results in session topography with puffs of known duration, mean flow rate, puff volume and inter-puff interval. Underlying data is available in S5 Dataset.
Fig 3.
N = 293 initial responses were received, N = 40 respondents were found eligible and N = 34 participants were enrolled. Data from all enrolled participants were included in the data analysis and are presented in this paper.
Table 2.
Cohort demographics.
Table 3.
Number of sessions retained as a result of phase 0—data integrity management.
Fig 4.
Descriptive cohort statistics for topography behavior.
Shown are the histograms illustrating the range of topography behavior characteristics associated with participants assigned to each flavor. The tobacco flavor was used by all 34 subjects for one week, while N = 17 used menthol and N = 17 used berry during the alternate week. Switching order was balanced and randomized.
Fig 5.
Descriptive cohort statistics for consumption behavior.
Shown are the histograms illustrating the range of topography behavior characteristics associated with participants assigned to each flavor. The tobacco flavor was used by all 34 subjects for one week, while N = 17 used menthol and N = 17 used berry for the other week. Switching order as balanced and randomized.
Fig 6.
Effect of flavor assignment on mean flow rate.
Shown are within-subjects pairwise comparison between flavor for each participant. The left column shows results for participants who were assigned T the first week, and the right column shows results for participants who were assigned T the second week. The top row shows particpants who switched between tobacco and menthol and the bottom row shows participants who switched between tobacco and berry. The mean and 95% CI are computed across all puffs taken by each participant during the 6 day observation period. The flavor for each data set is indicated by a T, M or B at the top of the plot for each participant’s flavor where T = Tobacco, M = Menthol, and B = Berry. Underlying data is available in S6, S7, S8, S9 Datasets.
Fig 7.
Effect of flavor assignment on mean puff duratio.
Shown are within-subjects pairwise comparison between flavor for each participant. The left column shows results for participants who were assigned T the first week, and the right column shows results for participants who were assigned T the second week. The top row shows particpants who switched between tobacco and menthol and the bottom row shows participants who switched between tobacco and berry. The mean and 95% CI are computed across all puffs taken by each participant during the 6 day observation period. The flavor for each data set is indicated by a T, M or B at the top of the plot for each participant’s flavor where T = Tobacco, M = Menthol, and B = Berry. Underlying data is available in S10, S11, S12, S13 Datasets.
Fig 8.
Effect of flavor assignment on mean puff volume.
Shown are within-subjects pairwise comparison between flavor for each participant. The left column shows results for participants who were assigned T the first week, and the right column shows results for participants who were assigned T the second week. The top row shows particpants who switched between tobacco and menthol and the bottom row shows participants who switched between tobacco and berry. The mean and 95% CI are computed across all puffs taken by each participant during the 6 day observation period. The flavor for each data set is indicated by a T, M or B at the top of the plot for each participant’s flavor where T = Tobacco, M = Menthol, and B = Berry. Underlying data is available in S14, S15, S16, S17 Datasets.
Table 4.
Test of proportions on topography behavior indicators.
Table 5.
Directionality effect of E-liquid flavor on topography behavior indicators.
Fig 9.
Effect of flavor assignment on average cumulative daily volume.
Shown are within-subjects pairwise comparison between flavor for each participant. The left column shows results for participants who were assigned T the first week, and the right column shows results for participants who were assigned T the second week. The top row shows participants who switched between tobacco and menthol and the bottom row shows participants who switched between tobacco and berry. The mean (circle) and 95% CI are computed as the daily average of all days having at least one puffing session during the 6 day observation period. The mean (X) is computed as the cumulative volume divided by 6 days. When the means overlap, the participant exhibited puffing behavior on every day. The flavor for each data set is indicated by a T, M or B at the top of the plot for each participant’s flavor where T = Tobacco, M = Menthol, and B = Berry. Underlying data is available in S18, S19, S20, S21 Datasets.
Fig 10.
Effect of flavor assignment on average daily puff count.
Shown are within-subjects pairwise comparison between flavor for each participant. The left column shows results for participants who were assigned T the first week, and the right column shows results for participants who were assigned T the second week. The top row shows participants who switched between tobacco and menthol and the bottom row shows participants who switched between tobacco and berry. The mean (circle) and 95% CI are computed as the daily average of all days having at least one puffing session during the 6 day observation period. The mean (X) is computed as the cumulative puff count divided by 6 days. When the means overlap, the participant exhibited puffing behavior on every day. The flavor for each data set is indicated by a T, M or B at the top of the plot for each participant’s flavor where T = Tobacco, M = Menthol, and B = Berry. Underlying data is available in S22, S23, S24, S25 Datasets.
Table 6.
Test of proportions on consumption behavior indicators.
Table 7.
Differences in 6-day cumulative volume between flavors.
Fig 11.
Interval plots for mean puff flow rate for different length monitoring periods.
Shown are means and 95% CI for participant 14 from the two-week flavor switching study calculated based on 1 session, 1 day and 1 week of data. Results show that using a monitoring period of less than 1 week would have resulted in a type II error. Underlying data is available in S26 Dataset.