## INTRODUCTION

Recent data indicate that American youths’ use of electronic nicotine delivery systems (ENDS) exceeds that of other tobacco products1. As of 2017, 11.7% of high schoolers and 3.3% of middle schoolers used ENDS in the past 30 days1. Research examining sociodemographic differences in ENDS use indicates that males2, adolescents of higher socioeconomic status3, and non-Hispanic White youth4 may be more likely to use ENDS. Although ENDS have been positioned as potential harm reduction tools for combustible cigarette smokers5, their use among adolescents remains problematic as ENDS solutions and aerosols contain numerous toxicants and carcinogens6, in addition to nicotine, an addictive substance with neurotoxic effects on the developing brain7.

Studies have identified several reasons for ENDS’ increasing popularity among adolescents, including greater visibility in the media8, combustible cigarette smoking cessation9, interest in flavors10, and peer influence11. Like other tobacco products12, motivations for ENDS use may vary with sociodemographic characteristics. Studies of US adults demonstrate that appealing flavors are more likely to be a reason for use among young adults13, and adult women are more likely to report using e-cigarettes because of their use by friends or family members14.

Limited research has examined differences in motivations for ENDS use among sociodemographic subgroups of adolescents. A clear understanding of these variations is valuable to help ensure that messages, interventions and policies are relevant to populations most vulnerable to ENDS use and are culturally tailored as needed. This study examines how adolescents’ motivations for ENDS use vary by sociodemographic characteristics, including age, gender, race/ethnicity and household income.

## METHODS

### Data

We analyzed data from the Wave 2 youth sample of the Population Assessment of Tobacco and Health (PATH) study (N=12172)15. PATH was a longitudinal cohort study of US youth and adults and its Wave 2 data collection occurred between 2014–2016. Further study design and sample details are described in Hyland et al.15 and the study questionnaire can be found at https://www.icpsr.umich.edu/icpsrweb/NAHDAP/studies/36231. Our sample for analysis consisted of 415 youth participants who were asked questions about their motivations for ENDS use. These questions were only asked to participants who indicated they had used ENDS in the past 30 days. PATH study procedures were approved by the Westat Institutional Review Board15.

### Measures

The primary measures of interest were questions asking youth to identify, from a list of 13 possibilities, the reasons they use ENDS (response options of yes/ no). Table 1 presents the full wording for each item. We examined how motivations varied across several sociodemographic characteristics available in the PATH Public Use File: age (12–14, 15–17 years), gender (female, male), race/ethnicity (Hispanic, non-Hispanic Black, non-Hispanic White, and other non-Hispanic ethnicity), and household income (obtained from the youth’s parent: <$10000,$10000–$24999,$25000–$49999,$50000–$99999, ≥$100000).

##### Table 1

Sample characteristics, United States, 2014–2016 (N=415 )

Per cent95% CIN (unweighted)
Age (years)
12–1419.59(15.65–24.24)88
15–1780.41(75.76–84.35)327
Gender
Male56.96(51.53–62.24)237
Female43.04(37.76–48.47)177
Race
Non-Hispanic White69.34(64.24–74.01)264
Non-Hispanic Black5.55(3.50–8.68)19
Non-Hispanic Other8.28(5.84–11.61)42
Hispanic16.83(13.67–20.56)90
Household income
Less than $100008.11(5.57–11.65)31$10000–$2499916.82(13.18–21.22)75$25000–$4999920.35(16.17–25.29)76$50000–$9999929.96(25.32–35.05)110$100000 or more24.77(19.56–30.83)84
Used flavored e-cigarette in past 30 days
Yes79.36(74.65–83.39)329
No10.92(8.2–14.39)42
Don't know9.72(7.18–13.03)43
Current combustible tobacco user
Non-combustible at W1 and W246.12(40.95–51.38)181
Combustible at W1 only5.5(3.63–8.27)22
New W2 combustible (combustible at W2 only)23.83(18.95–29.52)95
Current combustible use at W1 and W224.54(20.11–29.58)103
Days used e-cigarette in past 30 daysa7.751(6.831–8.672)
Reasons for e-cigarette use
1. It comes in flavors I like77.90(73.07–82.07)327
2. They might be less harmful to me than cigarettes75.01(70.09–79.37)306
3. They might be less harmful to people around me74.08(68.61–78.90)307
4. It helps people to quit smoking cigarettesb63.48(57.22–69.32)162
5. They can be used in places where smoking can’t58.68(53.24–63.92)242
6. They don't bother non-tobacco users56.40(50.74–61.91)229
7. They don't smell53.80(48.58–58.93)229
8. They are affordable48.18(43.91–52.48)208
9. I like socializing while using them45.80(41.64–50.01)193
10. People in the media or other public figures use them36.11(30.91–41.65)150
11. People who are important to me use them34.88(29.69–40.46)143
12. It feels like smoking a regular cigarette25.09(20.31–30.57)107
13. The advertising appeals to me14.18(10.63–18.66)60

a Sample restricted to youth who are past 30-day e-cigarette users.

b Asked to youth who last smoked a cigarette within the past year.

### Data analysis

We used the weighting and variance estimation procedures provided in the PATH user guide. We calculated descriptive statistics to characterize our sample, then computed crosstabs, with chi-squared tests of significance, to examine bivariate differences in the prevalence of reported motivations for use across identified sociodemographic characteristics. We conducted logistic regression analyses to examine unique associations between sociodemographics and motivations for ENDS use, entering all sociodemographic variables together in models for each motivation, controlling for current combustible tobacco use, intensity of ENDS use (number of days used in past 30 days) and whether the participant uses a flavored ENDS. Analyses were conducted using Stata 14.

## RESULTS

Table 1 presents full descriptive statistics for the analytic sample. The most commonly selected reasons for ENDS use were: appealing flavors (77.9%), ‘they might be less harmful to me than cigarettes’ (75.0%) and ‘they might be less harmful to people around me’ (74.1%). Bivariate analyses revealed several differences across sociodemographic characteristics in motivations for ENDS use (Table 2). Among females, 82.9% reported using ENDS because the product comes in appealing flavors (compared to 74.0% of males), 31.3% reported using ENDS because the product feels like smoking cigarettes (compared to 20.5% of males), and 43.3% reported using ENDS because people who are important to them use them (compared to 28.2% of males). Just over half (53.6%) of non-Hispanic Black youth reported use due to appealing flavors, compared to non-Hispanic Whites (78.8%), Hispanics (76.6%), and those of other non-Hispanic ethnicities (89.3%). Among older adolescents (15–17 years old), 56.5% reported using ENDS because the products do not smell bad, compared to 42.8% of younger adolescents (12–14 years old). Among those with household incomes of less than $10000 a year, 16.3% reported using ENDS because the advertising appealed to them, compared to 26.4% of those with household incomes of$10000– $24999, 15.0% of those with household incomes of$25000–$49999, 11.5% of those with household incomes of$50000–$99999 and 4.34% of those with household incomes of$100000 or more.

##### Table 2

Bivariate differences in e-cigarette reasons for use by sociodemographic factors, United States, 2014– 2016 (N=415 )

It comes in flavors I like
They might be less harmful to me than cigarettes
They might be less harmful to people around me
N%95% CIN%95% CIN%95% CI
Overall32777.85(73.01–82.03)30674.96(70.02–79.33)307748.00(68.61–78.90)
Age (years)
12–147179.99(70.71–86.88)6980.02(69.78–87.42)6879.32(68.17–87.29)
15–1725677.38(71.70–82.21)23773.81(68.04–78.86)23972.83(67.21–77.80)
Gender
Male17974.00(67.79–79.38)*17575.54(68.57–81.39)17472.51(64.65–79.18)
Female14782.93(76.02–88.15)*13074.20(67.71–79.78)13276.04(68.97–81.93)
Race/Ethnicity
Non-Hispanic White21078.79(72.88–83.70)*19674.52(68.31–79.87)19372.02(65.40–77.81)
Non-Hispanic Black1153.62(27.28–78.09)*1689.57(67.44–97.27)1481.03(59.06–92.67)
Other race3789.30(75.69–95.72)*3278.90(62.72–89.27)3382.36(65.44–92.01)
Hispanic6976.59(65.42–84.98)*6270.20(58.85–79.52)6776.32(65.61–84.49)
Household Income
<$100002271.82(53.87–84.77)2268.38(49.20–82.85)2271.35(49.16–86.51)$10000–$249995979.10(68.54–86.79)5579.79(71.14–86.35)5471.80(55.73–83.73)$25000–$499996279.42(67.52–87.75)5573.00(61.16–82.27)6078.16(67.16–86.23)$50000–$999998677.94(68.67–85.06)7671.06(61.46–79.08)7971.29(61.95–79.10)$100000 or more6877.26(61.90–87.67)6676.47(63.46–85.88)6172.53(59.63–82.51)
It helps people to quit smoking cigarettes
They can be used in places where smoking can’t
They don’t bother non-tobacco users
N%95% CIN%95% CIN%95% CI
Overall16263.48(57.22–69.32)24258.81(53.36–64.05)22956.31(50.65–61.81)
Age (years)
12–143164.75(50.33–76.91)5160.11(48.71–70.51)4552.41(41.32–63.26)
15–1713163.20(56.76–69.21)19158.33(52.33–64.10)18457.39(51.06–63.49)
Gender
Male9668.70(59.54–76.61)14560.81(52.65–68.41)13357.54(50.55–64.24)
Female6657.58(48.27–66.39)9756.16(49.32–62.77)9554.68(45.90–63.18)
Race/Ethnicity
Non-Hispanic White10060.51(52.82–67.72)15560.00(53.15–66.49)14656.09(48.29–63.60)
Non-Hispanic Black783.42(48.10–96.47)1048.39(22.39–75.28)1165.32(40.20–84.07)
Other race1767.83(42.71–85.64)2559.39(42.56–74.27)2154.25(36.62–70.88)
Hispanic3869.52(55.02–80.96)5256.36(45.67–66.49)5155.90(45.63–65.69)
Household Income
<$100001377.36(47.60–92.78)1444.26(27.61–62.30)1545.71(27.19–65.51)$10000–$249993968.42(51.14–81.77)4968.39(54.87–79.37)4459.42(45.45–72.01)$25000–$499993563.61(49.71–75.55)4355.76(43.25–67.58)4356.12(42.81–68.60)$50000–$999993760.43(47.10–72.37)6257.04(46.70–66.80)6154.85(44.87–64.46)$100000 or more2860.87(44.98–74.75)4857.24(43.17–70.23)4254.57(40.90–67.59)
They don’t smell
They are affordable
I like socializing while using them
N%95% CIN%95% CIN%95% CI
Overall22953.70(48.48–58.83)20848.07(43.79–52.37)19345.68(41.50–49.92)
Age (years)
12–144042.83(32.72–53.58)*4346.30(35.65–57.30)3437.20(28.14–47.26)
15–1718956.46(50.47–62.26)*16548.64(43.28–54.02)15947.86(42.56–53.20)
Gender
Male12551.38(44.84–57.88)13253.37(46.46–60.17)11244.44(38.31–50.73)
Female10356.75(49.42–63.79)7540.96(32.81–49.64)8047.33(40.29–54.48)
Race/Ethnicity
Non-Hispanic White14253.02(45.85–60.06)11945.02(39.89–50.26)12245.21(40.31–50.21)
Non-Hispanic Black941.57(21.55–64.82)836.85(16.20–63.77)630.63(11.72–59.48)
Other race2866.84(49.25–80.71)2863.18(46.34–77.32)1744.34(26.94–63.25)
Hispanic5054.48(42.12–66.31)5357.53(45.70–68.56)4853.96(42.93–64.63)
Household Income
<$100001444.27(25.15–65.25)1438.44(22.45–57.40)1338.60(22.29–57.96)$10000–$249994254.14(41.75–66.03)3645.81(33.11–59.08)3547.68(35.85–59.77)$25000–$499994253.85(41.28–65.94)3644.40(32.73–56.73)3140.88(29.70–53.08)$50000–$999996052.70(44.02–61.22)5748.78(39.51–58.14)5951.26(40.70–61.71)$100000 or more5158.30(45.57–70.01)4350.76(38.02–63.39)3943.73(31.83–56.40)
People in the media or other public figures use them
People who are important to me use them
It feels like smoking a regular cigarette
N%95% CIN%95% CIN%95% CI
Overall15036.19(30.98–41.74)14334.74(29.56–40.31)10725.15(20.35–30.64)
Age (years)
12–143945.10(34.61–56.04)3134.86(24.60–46.75)2325.68(16.63–37.44)
15–1711133.93(28.33–40.02)11234.89(29.05–41.22)8424.94(20.01–30.63)
Gender
Male8634.78(28.35–41.83)6728.24(22.63–34.63)**5220.49(15.68–26.32)*
Female6438.06(29.98–46.86)7543.28(35.62–51.27)**5531.30(23.46–40.36)*
Race/Ethnicity
Non-Hispanic White8833.91(28.01–40.36)9836.12(30.25–42.44)6724.70(18.71–31.86)
Non-Hispanic Black726.77(9.28–56.62)629.58(13.18–53.75)837.13(18.64–60.35)
Other race1847.77(30.13–65.99)1744.34(28.13–61.85)1330.46(17.98–46.68)
Hispanic3742.63(32.96–52.91)2226.62(18.62–36.51)1920.07(13.59–28.61)
Household Income
<$100001339.31(21.41–60.63)826.72(12.88–47.36)927.16(12.64–49.01)*$10000–$249993447.66(35.99–59.59)2226.33(17.31–37.91)2432.86(22.84–44.73)*$25000–$499992838.73(27.35–51.48)2534.49(23.67–47.20)2227.50(18.70–38.48)*$50000–$999993127.92(19.44–38.34)4037.60(29.24–46.77)2828.15(19.64–38.57)*$100000 or more2932.44(22.35–44.49)3337.38(26.71–49.45)1313.80(8.58–21.46)*
N%95% CI
Overall6014.18(10.63–18.66)
Age (years)
12–142021.50(13.13–33.16)
15–174012.37(8.83–17.06)
Gender
Male3814.45(10.01–20.40)
Female2213.90(9.02–20.80)
Race/Ethnicity
Non-Hispanic White3513.02(8.91–18.64)
Non-Hispanic Black417.05(5.21–43.48)
Other race514.35(5.44–32.76)
Hispanic1617.87(10.69–28.35)
Household Income
<$10000616.27(7.17–32.85)**$10000–$249991826.42(16.65–39.22)**$25000–$499991215.03(7.80–27.01)**$50000–$999991311.45(6.65–19.03)**$100000 or more44.34(1.56–11.51)**

* p<0.05

** p<0.01

*** p<0.001

N is unweighted, percentages are weighted. Cells may not sum to overall totals due to missing data.

Logistic regression analyses (Table 3) indicated that variations in use behavior were associated with several motivations for ENDS use. These analyses indicate that compared to non-Hispanic Whites, those of non-Hispanic ethnicities other than non-Hispanic White or Black had a higher likelihood of reporting using ENDS because they are affordable (AOR=2.684, 95% CI: 1.044–6.899), and females had a higher likelihood of reporting using ENDS because people important to them use ENDS (AOR=1.895, 95% CI: 1.128–3.184) and a lower likelihood of reporting using ENDS because they are affordable (AOR=0.538, 95% CI: 0.296–0.976). Combustible tobacco users had a higher likelihood of reporting using ENDS, because they compared favorably to cigarettes in that they do not smell, can be used in places cigarettes are not allowed, and feel like smoking a cigarette. Flavored ENDS users had a higher likelihood of reporting using ENDS due to the appealing flavors, reduced harm perceptions, and use in socialization or because people important to them use ENDS. Adolescents who use ENDS more intensely had a higher likelihood of reporting socialization, reduced harm to others, and not bothering other people as reasons for use.

##### Table 3

Adjusted odds ratios for association between sociodemographics and tobacco variables with motivations for e–cigarette use, United States, 2014–2016 (N=415 )

It comes in flavors I like
They might be less harmful to me than cigarettes
They might be less harmful to people around me
It helps people to quit smoking cigarettes
AOR95% CIAOR95% CIAOR95% CIAOR95% CI
15–17 years old (ref: 12–14 years old)0.590(0.291–1.198)0.608(0.295–1.25)0.501(0.244–1.030)0.668(0.308–1.449)
Female (ref: Male)1.751(0.928–3.305)0.992(0.577–1.707)1.415(0.781–2.564)0.636(0.337–1.202)
Race/ethnicity (ref: Non-Hispanic White)
Non-Hispanic Black0.512(0.117–2.236)4.818(0.623–37.275)2.594(0.688–9.778)4.221(0.262–68.03)
Other race1.875(0.593–5.929)1.309(0.489–3.503)2.093(0.732–5.986)1.702(0.421–6.882)
Hispanic1.000(0.510–1.958)0.648(0.328–1.279)1.287(0.572–2.894)1.174(0.506–2.723)
Household income (ref: <$10000/year)$10000–$249991.385(0.481–3.984)1.757(0.612–5.044)0.838(0.252–2.788)0.625(0.087–4.497)$25000–$499991.516(0.533–4.316)1.116(0.377–3.301)1.188(0.349–4.040)0.435(0.064–2.93)$50000–$999991.222(0.433–3.449)1.025(0.365–2.878)0.773(0.214–2.788)0.402(0.054–2.999)$100000 or more1.255(0.388–4.061)1.464(0.441–4.857)0.972(0.255–3.704)0.427(0.056–3.277)
Uses a flavored e-cigarette (ref: does not use flavored e-cigarette)2.300(1.153–4.585)*1.220(0.642–2.316)1.976(1.082–3.605)*1.978(0.89–4.395)
Combustible tobacco use during Wave 2 (ref: not during Wave 2)1.416(0.746–2.687)1.525(0.855–2.717)1.337(0.735–2.434)1.275(0.47–3.462)
Days used e-cigarette in past 30 days1.035(0.994–1.078)1.025(0.993–1.058)1.058(1.022–1.095)**1.011(0.976–1.047)
They can be used in places where smoking can’t
They don’t bother non–tobacco users
They don’t smell
They are affordable
AOR95% CIAOR95% CIAOR95% CIAOR95% CI
15–17 years old (ref: 12–14 years old)0.767(0.398–1.478)1.167(0.649–2.098)1.595(0.829–3.069)0.856(0.463–1.584)
Female (ref: Male)0.867(0.524–1.435)0.916(0.548–1.563)1.216(0.752–1.965)0.538(0.296–0.976)*
Race/ethnicity (ref: Non-Hispanic White)
Non-Hispanic Black1.111(0.271–4.550)1.998(0.610–6.552)0.762(0.221–2.630)1.039(0.234–4.610)
Other race1.005(0.386–2.619)1.022(0.440–2.374)1.715(0.699–4.208)2.684(1.044–6.899)*
Hispanic0.835(0.442–1.579)0.913(0.447–1.865)1.632(0.780–3.415)1.934(0.995–3.759)
Household income (ref: <$10000/year)$10000–$249992.221(0.772–6.387)1.837(0.615–5.487)1.457(0.509–4.347)1.119(0.369–3.395)$25000–$499991.192(0.408–3.481)1.420(0.451–4.476)1.635(0.543–4.922)1.186(0.382–3.675)$50000–$999991.345(0.515–3.512)1.280(0.500–3.278)1.361(0.450–4.118)1.412(0.476–4.191)$100000 or more1.466(0.512–4.198)1.325(0.522–3.364)1.869(0.572–6.110)1.670(0.527–5.299)
Uses a flavored e-cigarette (ref: does not use flavored e-cigarette)1.663(0.915–3.019)1.252(0.695–2.258)1.586(0.764–3.291)1.827(0.982–3.400)
Combustible tobacco use during Wave 2 (ref: not during Wave 2)2.340(1.431–3.828)**1.118(0.714–1.751)1.740(1.117–2.711)*1.483(0.892–2.466)
Days used e-cigarette in past 30 days1.061(1.031–1.093)***1.037(1.004–1.070)*1.012(0.983–1.042)1.023(0.995–1.051)
I like socializing while using them
People in the media or other public figures use them
People who are important to me use them
It feels like smoking a regular cigarette
AOR95% CIAOR95% CIAOR95% CIAOR95% CI
15–17 years old (ref: 12–14 years old)1.247(0.684–2.276)0.741(0.409–1.344)0.922(0.477–1.783)0.802(0.363–1.772)
Female (ref: Male)1.212(0.743–1.976)1.193(0.668–2.132)1.895(1.128–3.184)*1.761(1.060–2.927)*
Race/ethnicity (ref: Non-Hispanic White)
Non-Hispanic Black0.807(0.188–3.464)0.812(0.212–3.101)0.997(0.307–3.236)2.740(1.000–7.513)*
Other race0.967(0.375–2.491)1.966(0.796–4.852)1.494(0.616–3.623)0.801(0.253–2.535)
Hispanic1.581(0.848–2.948)1.197(0.656–2.184)0.657(0.347–1.246)0.674(0.369–1.231)
Household income (ref: <$10000/year)$10000–$249991.438(0.543–3.809)1.118(0.415–3.011)1.011(0.284–3.598)1.556(0.489–4.955)$25000–$499991.042(0.365–2.978)0.904(0.304–2.689)1.513(0.438–5.224)1.142(0.366–3.560)$50000–$999991.426(0.623–3.261)0.521(0.181–1.502)1.444(0.476–4.382)1.310(0.458–3.748)$100000 or more1.138(0.391–3.312)0.728(0.244–2.166)1.439(0.463–4.476)0.497(0.168–1.467)
Uses a flavored e-cigarette (ref: does not use flavored e-cigarette)2.221(1.280–3.853)**1.208(0.64–2.281)3.005(1.532–5.892)**0.947(0.393–2.285)
Combustible tobacco use during Wave 2 (ref: not during Wave 2)1.157(0.701–1.910)1.177(0.705–1.963)0.874(0.524–1.455)3.810(2.079–6.979)***
Days used e-cigarette in past 30 days1.033(1.003–1.064)*1.006(0.978–1.034)1.012(0.985–1.040)1.008(0.975–1.042)
AOR95% CI
15–17 years old (ref: 12–14 years old)0.488(0.194–1.225)
Female (ref: Male)0.807(0.393–1.656)
Race/ethnicity (ref: Non-Hispanic White)
Non-Hispanic Black2.542(0.523–12.348)
Other race0.884(0.154–5.091)
Hispanic1.493(0.662–3.368)
Household income (ref: <$10000/year)$10000–$249991.763(0.380–8.168)$25000–$499990.918(0.210–4.006)$50000–$999990.817(0.223–3.000)$100000 or more0.289(0.068–1.220)
Uses a flavored e-cigarette (ref: does not use flavored e-cigarette)0.900(0.423–1.913)
Combustible tobacco use during Wave 2 (ref: not during Wave 2)2.589(1.301–5.151)**
Days used e-cigarette in past 30 days1.003(0.960–1.048)

* p<0.05

** p<0.01

*** p<0.001

## DISCUSSION

Appealing flavors was the most commonly reported motivation for using ENDS, but was mentioned more often among females. It is possible that flavors may be especially attractive to adolescent girls, as similar preferences for flavored products are observed in other products such as alcohol16. Perceptions of reduced harm to self and to others were the next most commonly reported reasons for ENDS use across all youth. This reason did not differ across sociodemographic groups, indicating that perceptions of reduced harm are important for most adolescent ENDS users, regardless of sociodemographic characteristics. Advertising was not commonly reported as a reason for ENDS use.

Logistic regression analyses revealed that similarity or exchangeability with cigarettes is an important reason for ENDS use among combustible tobacco users. Further research should explore whether ENDS are being used as an alternative to combustible tobacco among this group. More intense ENDS use was associated with reasons involving other people, indicating that social benefit may encourage more intense use.

These findings offer several insights that could be helpful for policy and practice. First, given flavor’s importance in motivating product use, limiting appealing flavors may be an important approach to reduce use among youth, particularly female youth. Second, measures to increase the price of ENDS may have more of an effect on those of other non-Hispanic ethnicities compared to non-Hispanic Whites, as this group had a higher likelihood of reporting affordability as a reason for ENDS use. Conversely, price-increasing measures may have less of an effect on females compared to males, as females were less likely to report affordability as a motivation for ENDS use. Additionally, given the high number of youth overall who report using ENDS because they believe they are less harmful to them than cigarettes, education campaigns should communicate the potential harms of ENDS. Finally, given the prevalence of youth reporting using ENDS because people who are close to them use them, campaigns or interventions that leverage the role of important people in youths’ lives may be a useful strategy.

Several limitations must be considered when interpreting our findings. First, individuals may be more likely to select those motivations that come quickly to mind. With no opportunity to report motivations outside those included in the PATH study questionnaire, other important motivations may not be reflected in the study and this analysis. Second, only youth who had used ENDS in the past 30 days were asked questions about motivations for use. Therefore, we cannot draw conclusions about motivations for use among individuals outside this group. Moreover, this sample size was relatively small. While weighting procedures were employed, future work should be done with larger samples. Finally, data on specific racial/ethnic groups other than non-Hispanic White, non-Hispanic Black and Hispanic were not available in the data file, so we are unable to draw conclusions about motivations for ENDS use among these specific populations.

## CONCLUSIONS

A long history of health disparities in tobacco product use17 underscores the need for tobacco control policies and interventions that effectively reduce ENDS use among vulnerable subpopulations of adolescents. Understanding the motivations for use among sociodemographic subgroups is an initial step towards informing the development of policies and interventions with equally distributed benefits.

## CONFLICTS OF INTEREST

The authors declare that they have no competing interests, financial or otherwise, related to the current work. M. B. Moran reports grants from National Institute on Drug Abuse/US Food and Drug Administration Center for Tobacco Products, during the conduct of the study. The rest of the authors have also completed and submitted an ICMJE form for disclosure of potential conflicts of interest.