Participant Characteristics and Smoking History
Table 1 describes participants’ sociodemographic and smoking history characteristics.
Smokers typically make multiple quit attempts [36] as was true of almost half of our participants. The majority of participants began smoking before age 18, smoked for at least 16 years, and about half reported smoking more than 20 cigarettes per day. The vast majority of the sample identified as “White” with those aged 45-54 the most represented. There were slightly more females and most lived in suburbia or rural areas.
Table 1. Participant Characteristics and Smoking History
Demographics n (%)
|
Gender
|
Female
|
85 (55.6%)
|
Male
|
58 (44.4%)
|
Age (in years)
|
18-24
|
2 (1.30%)
|
25-34
|
49 (31.8%)
|
35-44
|
36 (23.4%)
|
45-54
|
57 (37.0%)
|
55-64
|
10 (6.49%)
|
Residence
|
Urban
|
35 (22.9%)
|
Suburban
|
66 (43.1%)
|
Rural
|
52 (34.0%)
|
Race
|
White
|
|
Yes
|
152(97.4%)
|
No
|
4 (2.6%)
|
African American
|
|
Yes
|
2(1.3%)
|
No
|
154 (98.7%)
|
Asian American
|
|
Yes
|
2(1.3%)
|
No
|
154 (98.7%)
|
American Indian
|
|
|
Yes
|
10 (6.4%)
|
|
No
|
146 (93.6%)
|
Smoking History n (%)
|
Age started smoking
|
≤ 13 years
|
33 (21.4%)
|
14-15 years
|
53 (34.4%)
|
16-17 years
|
43 (27.9%)
|
≥ 18 years
|
25 (16.2%)
|
Years smoked
|
≤ 15 years
|
46 (30.9%)
|
16-25 years
|
37 (24.8%)
|
26-35 years
|
40 (26.8%)
|
≥ 36 years
|
26 (17.4%)
|
Cigarettes per day
|
≤ 20
|
72 (47.4%)
|
≥ 21
|
80 (52.6%)
|
Number of previous quit attempts
|
≤ 5 times
|
75 (54.7%)
|
6-10 times
|
34 (24.8%)
|
≥ 11 times
|
28 (20.4%)
|
Investigator-Developed Questions
Presence and Quality of Sensory Experiences and Cues Using an E-Cigarette
Responses from ten investigator-developed questions indicated that the majority of participants experienced respiratory sensations when using their e-cigarettes and enjoyed the sensations (Table 2). The presence of sensations varied based on their location in the respiratory tract, with sensations in the throat being the most common and in the lungs the least. Enjoyment of sensations varied, with the tongue and throat being the most enjoyable.
Importance of Sensory Experiences’ Influence on Cessation Outcomes
Table 3 describes participants’ responses to the importance of sensations and the extent to which they believed these sensations contributed to their ability to quit smoking. Participants were asked to rate on a 7 point Likert scale (Not at all (1) to extremely (7) the importance of the sensation of the vapor. The proportion of responses to the statement, “The feeling of the vapor when I used my e-cigarette is important to me,” was: not at all (5.03%), very little (5.66%), a little (5.03%), moderately (17.61%), a lot (18.87%), quite a lot (25.16%), and extremely (22.64%). Together, eighty four percent of participants reported the sensation of the vapor as moderately to extremely important.
Participants were asked to rate on a 7 point Likert scale (Not at all (1) to extremely (7)) the extent to which sensations associated with e-cigarette use influenced cessation outcomes. The proportions of responses to the statement, “The feeling of the vapor when I use my e-cigarette contributed to my smoking cessation success,” were: not at all (3.18%), very little (1.91%), a little (3.82%), moderately, (7.01%), a lot (11.46%), quite a lot (20.38%), and extremely (52.23%). Together, ninety one percent of participants believed the sensations accompanying e-cigarette use contributed moderately to extremely to their smoking cessation success.
Table 2. Respiratory Tract Sensations and Enjoyment Reported During E-Cigarette Use:
*Sensation
|
Experiences the Sensation
|
95% Confidence Interval
|
**Enjoys the Sensation
|
95% Confidence Interval
|
Throat
|
97%
|
93%, 99%
|
95%
|
90%, 98%
|
Tongue
|
94%
|
89%, 97%
|
98%
|
94%, 99%
|
Windpipe
|
75%
|
67%, 81%
|
86%
|
80%, 91%
|
Nose
|
72%
|
64%, 79%
|
85%
|
78%, 90%
|
Lungs
|
67%
|
60%, 74%
|
82%
|
75%, 87%
|
*Sensation: Investigator-developed questions: I feel the vapor in my throat when I use my e-cigarette; I feel the vapor on my tongue when I use my e-cigarette; I feel the vapor in my windpipe when I use my e-cigarette; I feel the vapor in my nose when I use my e-cigarette; I feel the vapor in my lungs when I use my e-cigarette. **Enjoys the Sensation: Investigator-developed questions: I enjoy the feeling of the vapor in my throat when I use my e-cigarette; I enjoy the feeling of the vapor on my tongue when I use my e-cigarette; I enjoy the feeling of the vapor in my windpipe when I use my e-cigarette; I enjoy the feeling of the vapor in my nose when I use my e-cigarette; I enjoy the feeling of the vapor in my lungs when I use my e-cigarette.
Table 3. Importance of Sensory Experiences’ Influence on Cessation Outcomes
Statement
|
Not at All (1)
|
Very Little (2)
|
A little (3)
|
Moderately
(4)
|
A lot
(5)
|
Quite A lot (6)
|
Extremely
(7)
|
The feeling the vapor is important to me when I use my e-cigarette
|
5.03%
|
5.66%
|
5.03%
|
17.61%
|
18.87%
|
25.16%
|
22.64%
|
The feeling of the vapor when I use my e-cigarette contributed to my smoking cessation success
|
3.18%
|
1.91%
|
3.82%
|
7.01%
|
11.46%
|
20.38%
|
52.23%
|
The Modified Cigarette Evaluation Questionnaire (mCEQ)
As can be seen in Table 4, mean scores on the five domains of the mCEQ based on the 7 point Likert scale 1 (not at all) to 7 (extremely) indicate that participants reported high levels of satisfaction (mean of 19.7 out of a maximum of 21), enjoyment (mean of 5.6 out of a maximum of 7), and craving reductions (mean of 6.0 out of a maximum of 7); moderate levels of psychological reward (mean of 22.2 out of a maximum of 35); and low levels of aversion to e-cigarette use (mean of 2.4 out of a maximum of 14). In fact, ninety percent of participants reported no aversion to e-cigarette use with questions specifically asking about nausea and dizziness.
As can be seen in Table 5, scores on the smoking satisfaction and enjoyment domains of the mCEQ varied significantly according to the age at which the participant began smoking (13 years or younger, 14-15 years, 16-17 years or 18 years or older). ANOVA yielded differences between the four age groups on the mCEQ Satisfaction domain (overall p=0.013), and the post-hoc Tukey HSD test indicated that the 16-17 year-old group (mean + sd: 19.2 + 1.97) had a significantly lower mCEQ Satisfaction score compared to the 13 year-old and younger group (mean + sd: 20.4 + 1.23), p = 0.015. The non-parametric Kruskal-Wallis test indicated an overall association between the age the participant began smoking and the mCEQ Enjoyment domain score (overall p=0.017). Post-hoc testing (Dunn-Holm) showed a significant difference in the median mCEQ Enjoyment score, between the 16-17 year-old group (Median [IQR] of 5.00 [4.00;6.00]) and both the 14-15 year-old group (Median [IQR] of 6.00 [5.00;7.00]) and the 13 year-old and younger group (Median [IQR] of 6.00 [5.00;7.00]), p =0.026 and p = 0.047 respectively. In addition, enjoyment of e-cigarette use differed according to years smoked (overall p=0.038). After adjusting for multiple comparisons, there was a trend observed between those who smoked 26-35 years vs. 36 or more years, with a p-value of 0.061 for the pairwise comparison, suggesting that the test might be underpowered to detect the difference.
The majority (96% [95% CI = 89%, 97%]) of participants reported moderate to extreme reductions in nicotine craving with e-cigarette use as reflected in responses to the single item mCEQ question, “Does your e-cigarette immediately reduce your cravings for nicotine?”[34] Women scored significantly higher on the Craving Reduction domain compared to men (Median of 7.0 [6.00;7.00] vs 6.0 [5.00;7.00], p=0.023). As seen in table 4, there were no statistically significant associations observed between mCEQ domains and baseline age, type of residence, number of cigarettes smoked daily and number of quit attempts.
Table 4. Mean and Median Scores on the Five Domains of the mCEQ
Domain *
|
Mean (sd) Score
|
Median [IQR] Score
|
N
|
Smoking Satisfaction
|
19.7 (2.0)
|
21.0 [19.0; 21.0]
|
155
|
Psychological Reward
|
22.2 (6.3)
|
22.0 [18.0; 26.5]
|
155
|
Enjoyment of Respiratory Tract Sensations
|
5.6 (1.4)
|
6.0 [5.0; 7.0]
|
156
|
Craving Reduction
|
6.0 (1.3)
|
6.0 [6.0; 7.0]
|
156
|
Aversion
|
2.4 (1.2)
|
2.0 [2.0; 2.0]
|
155
|
*Smoking Satisfaction=average of mCEQ questions #1 (Was smoking satisfying?), #2 (Does the e-cigarettes taste good?), and #12 (Do you enjoy using your e-cigarette?); Psychological Reward=average of mCEQ questions #4 (Does using your e-cigarette calm you down?), #5 (Does using your e-cigarette make you feel more awake?), #6 (Does using your e-cigarette make you feel less irritable?), #7 (Does using your e-cigarette help you concentrate?), and #8 (Does using your e-cigarette reduce your hunger for food?); Enjoyment of Respiratory Tract Sensation: mCEQ questions #3 (Do you enjoy the sensation in your throat and chest?); Craving Reduction: mCEQ question #11 (Does using your e-cigarette immediately reduce your craving for nicotine?); and Aversion=average of mCEQ questions #9 (Does using your e-cigarette make you dizzy?) and #10 (Does using your e-cigarette make you nauseous?). * Note: Questions on the mCEQ were adapted to refer to e-cigarettes and e-cigarette use.
*Smoking Satisfaction=average of mCEQ questions #1 (Was e-cigarette use satisfying?), #2 (Does the e-cigarettes taste good?), and #12 (Do you enjoy using your e-cigarette?); Psychological Reward=average of mCEQ questions #4 (Does using your e-cigarette calm you down?), #5 (Does using your e-cigarette make you feel more awake?), #6 (Does using your e-cigarette make you feel less irritable?), #7 (Does using your e-cigarette help you concentrate?), and #8 (Does using your e-cigarette reduce your hunger for food?); Enjoyment of Respiratory Tract Sensation: mCEQ questions #3 (Do you enjoy the sensation in your throat and chest?); Craving Reduction: mCEQ question #11 (Does using your e-cigarette immediately reduce your craving for nicotine?); and Aversion=average of mCEQ questions #9 (Does using your e-cigarette make you dizzy?) and #10 (Does using your e-cigarette make you nauseous?).
Table 5. Association of Demographics and Smoking History and Domains of the Modified Cigarette Evaluation Questionnaire (mCEQ)
mCEQ Domainsa
|
Smoking Satisfaction
|
Psychological Reward
|
Enjoyment of Respiratory Tract Sensations
|
Craving Reduction
|
Aversion
|
Gender
Male
Female
|
19.5+/-1.94
19.8+/-2.15
|
22 (19.0;25.2)
23 (18.0;28)
|
6.0 (5.0;7.0)
6.0 (5.0;7.0)
|
6.0 (5.0; 7.0)
7.0(6.0;7.0)*
|
2.0(2.0;2.0)
2.0(2.0;2.0)
|
Baseline age
18-34
35-44
45+
|
19.7+/-2.01
20.2+/-1.33
19.5+/2.29
|
23.0(21.0;26.5)
21.0(15.526.0)
23.0(18.0;27.0)
|
6.0 (5.0;7.0)
6.0 (4.0;7.0)
6.0 (5.0;7.0)
|
7.0(6.0;7.0)
6.5(5.75;7.0)
6.0(5.0;7.0)
|
2.0(2.0;2.0)
2.0(2.0;2.0)
2.0(2.0;2.0)
|
Residence Type
Rural
Suburban
Urban
|
19.9+/-1.93
19.7+/-1.74
19.3+/-2.73
|
22.5(19.0;26.0)
22.0(17.2;26.8)
23.0(19.0;27.5)
|
6.0 (5.0;7.0)
6.0 (4.25; 7.0)
6.0 (5.0;7.0)
|
6.0(6.0;7.0)
7.0(5.25;7.0)
7.0(4.50;7.0)
|
2.0(2.0;2.0)
2.0(2.0;2.0)
2.0(2.0;2.0)
|
Age Began Smoking
<13 years
14-15 years
16-17 years
18+ years
|
20.4 +/-1.23*
*20.1+/- 1.26
19.2+/1.97**
19.5 +/-2.52
|
23.0(20.0;27.0)
22.0(18.0;27.0)
22.0(18.0;26.0)
24.0(20.0;26.0)
|
6.0 (5.0; 7.0)**
6.0 (5.0; 7.0)
5.0 (4.0; 6.0)**
5.0 (5.0; 7.0)
|
7.0(6.0;7.0)
7.0 (6.0;7.0)
6.0 (6.0;7.0)
6.0 (5.0;7.0)
|
2.0(2.0;2.0)
2.0(2.0;2.0)
2.0(2.0;2.0)
2.0(2.0;2.0)
|
Years Smoked
≤15 years
16-25 years
26-35 years
36+ years
|
19.6+/-2.06
19.9+/-1.82
20.2+/-1.2
19.5+/-1.92
|
23.0(21.0;27.8)
22.0(17.0;26.0)
25.0(18.0;27.5)
20.5(17.2;26.0)
|
6.0 (5.0; 7.0) *
6.0 (4.0; 7.0)
6.5 (5.8; 7.0)
5.0 (5.0; 6.00)
|
6.0 (6.0; 7.0)
7.0 (5.0; 7.0)
7.0 (6.0; 7.0)
6.0(5.25;7.0)
|
2.0(2.0;2.0)
2.0(2.0;2.0)
2.0(2.0;2.0)
2.0(2.0;2.0)
|
Daily Number of Cigarettes Smoked
20 or <
21 or >
|
19.6+/-1.9
20.0+/-1.6
|
22.5(18.0;26.2)
22.0(18.0;27.0)
|
6.0(4.0;7.0)
6.0 (5.0;7.0)
|
6.0(5.75;7.0)
7.0(6.0;7.0)
|
2.0(2.0;2.0)
2.0(2.0;2.0)
|
Quit Attempts
<5 times
6-10 times
11+ times
|
19.6+/-1.89
20.0+/-1.63
20.1+/-1.71
|
22.0(17.5;26.0)
25.0(20.0;27.0)
23.0(20.5;27.5)
|
6.0(5.0;6.50)
6.0(5.0;7.0)
7.0(5.0;7.0)
|
6.0(5.0; 7.0)
7.0(6.0;7.0)
7.0(6.0;7.0)
|
2.0(2.0;2.0)
2.0(2.0;2.0)
2.0(2.0;2.0)
|
* Statistically significant differences (at p<0.05) were found between gender and craving reduction (p=0.023); ratings of smoking satisfaction and age participants began smoking (overall p=0.013); ratings of enjoyment and age began smoking (overall p=0.017); and ratings of enjoyment and years smoked (overall p=0.038).
** Post-Hoc Tests indicated that the 16-17 year-old group had significantly lower Satisfaction (p=0.015) and Enjoyment (p =0.047) scores compared to the 13 year-old and younger group. The 16-17 year-old group also had significantly lower Enjoyment scores compared to the 14-15 year-old group (p=0.026). There was a trend for higher Enjoyment scores between those who have been smoking 26-35 years compared to those smoking 36 years or more (p=0.061 after adjusting for multiple comparisons).
The Smoking Cue Appeal Survey (SCAS)
The experience of smoking cues with e-cigarette use was evaluated using the SCAS. As can be seen in Table 6, almost all participants (99% [95% CI = 95%, 100%]) reported a pleasant experience using their e-cigarettes. Pleasantness was especially attributed to a variety of sensory cues such as tasting, smelling and seeing the vapor and touching the device. As can be seen in Table 7, the age of participants was significantly related to the extent to which they experienced sensory cues associated with e-cigarettes as pleasant (p=,01). A Tukey HSD post-hoc test showed that 18-34 years had a lower mean SCAS total score (-14.55 + 5.45) indicating more perceived pleasantness compared to 45+ year olds (-11.54 + 6.11), p=0.012.
There were no statistically significant associations observed between SCAS scores and gender, age of initiation of smoking, years of smoking, type of residence, number of cigarettes smoked daily, and number of quit attempts.
Table 6. Smoking Cue Appeal Survey (SCAS): Sensory Cues attributed to “Pleasantness”
* Cue
|
Proportion reporting pleasantness
|
95% CI
|
|
|
|
Tasting the Vapor
|
98%
|
94%, 99%
|
Smelling the vapor
|
88%
|
82%, 93%
|
Touching the Device
|
78%
|
71%, 84%
|
Seeing the Vapor
|
76%
|
68%, 72%
|
Overall experience
|
99%
|
95%, 100%
|
Smell of another’s use
|
85%
|
78%, 90%
|
Taste of another’s use
|
35%
|
28%, 44%
|
Sight of another’s use
|
50%
|
42%, 58%
|
*Cue=the proportion of respondents who indicated use of their e-cigarette was pleasant, very pleasant, or extremely pleasant. NOTE: Questions on the SCASwere adapted to refer to e-cigarettes and e-cigarette use.
Table 7. Association of Demographics and Smoking History and Total SCAS Scores
|
Total SCAS Score Mean +/-SD
|
Overall
*P value and **Post Hoc
|
Gender
Male
Female
|
-12.82+/-4.89
-13.43+/-6.31
|
P=0.506
|
Baseline Age
18-34
35-44
45+
|
-14.55 +/-5.45
-14.00 +/-4.61
-11.54 +/-6.11
|
*P=0.01
** P=0.012
|
Residence Type
Rural
Suburban
Urban
|
2.00(2.00;2.00)
2.00(2.00;2.00)
2.00(2.00;2.00)
|
P=0.470
|
Age Began Smoking
<13 years
14-15 years
16-17 years
18+ years
|
-14.00(-17.00;-10.00)
-14.00(-19.00;-9.00)
-12.00(-15.00;-9.00)
-13.00(-18.00;-7.00)
|
0.384
|
Years Smoked
≤15 years
16-25 years
26-35 years
36+ years
|
-14.33+/-5.24
-14.05+/-5.54
-13.32+/-5.78
-10.83+/-5.06
|
0.070
|
Daily Number of Cigarettes Smoked
20 or <
21 or >
|
-13.34+/-5.35
-13.18=/-5.68
|
0.859
|
Quit Attempts
<5 times
6-10 times
11+ times
|
-13.01+/-5.23
-13.79+/-5.78
-12.96+/-5.73
|
0.764
|
*ANOVA: P<.05
** Post Hoc tests indicated that those 18-34 years had a lower mean SCAS total score (-14.55 + 5.45) indicating more perceived pleasantness compared to 45+ year olds (-11.54 + 6.11), p=0.012.