. 2020 Nov 24;3(11):e2015893. doi: 10.1001/jamanetworkopen.2020.15893

Table 1. Sociodemographic, Tobacco, and Other Substance Use Characteristics of the Unweighted Wave 1 Participants by Overall and by Wave 2 ENDS Unexposed and Exposed Groups^a.

Characteristic	Ever cigarette and never ENDS users at wave 1(n = 1096)^b		Unexposed group: never used ENDS at wave 2 (n = 987)^c		Exposed group
	Ever cigarette and never ENDS users at wave 1(n = 1096)^b		Unexposed group: never used ENDS at wave 2 (n = 987)^c		Used ENDS 1-5 d in previous 30 d at wave 2 (n = 75)^d		Used ENDS ≥6 d in previous 30 d at wave 2 (n = 34)^e
	No.	Estimate, %	No.	Estimate, %	No.	Estimate, %	No.	Estimate %^f
Matching variable (wave 1)
Mean age	1096	21.4	987	21.5	75	21.1	34	20.8
White	698	63.7	616	62.4	53	70.7	29	85.3
Female	609	55.6	549	55.6	37	49.3	23	67.7
Hispanic	276	25.2	249	25.2	20	26.7	7	20.6
Educational level
<High school degree	152	13.9	135	13.7	10	13.3	7	20.6
GED	65	5.9	55	5.6	6	8.0	4	11.8
High school degree	295	26.9	259	26.2	24	32.0	12	35.3
Some college or associate degree	435	39.7	396	40.1	28	37.3	11	32.4
≥College	149	13.6	142	14.4	7	9.3	0	0.0
Alcohol use
Never	197	18.0	173	17.5	16	21.3	8	23.5
Ever, no previous 12 mo	88	8.0	81	8.2	2	2.7	5	14.7
Previous 12 mo, excluding previous 30 d	193	17.6	179	18.1	10	13.3	4	11.8
Previous 30 d	618	56.4	554	56.1	47	62.7	17	50.0
Heavy drinker	148	13.5	122	12.4	21	28.0	5	14.7
Marijuana use
Never	447	40.8	403	40.8	30	40.0	14	41.2
Ever, no previous 12 mo	295	26.9	271	27.5	15	20.0	9	26.5
Previous 12 mo, excluding previous 30 d	140	12.8	124	12.6	11	14.7	5	14.7
Previous 30 d	214	19.5	189	19.2	19	25.3	6	17.7
Other substance use
Never	829	75.6	753	76.3	50	66.7	26	76.5
Ever, no previous 12 mo	131	12.0	116	11.8	12	16.0	3	8.8
Previous 12 mo, including previous 30 d	129	11.8	111	11.3	13	17.3	5	14.7
Cigarette smoking
Daily previous 30-d use	161	14.7	124	12.6	22	29.3	15	44.1
Nondaily previous 30-d use	241	22.0	210	21.3	22	29.3	9	26.5
No previous 30-d use	694	63.3	653	66.2	31	41.3	10	29.4
Previous 30-d non-cigarette combustible use	147	13.4	134	13.6	8	10.7	5	14.7
Previous 30-d non-ENDS noncombustible use	54	4.9	43	4.4	7	9.3	4	11.8
Previous 12-mo quit attempt
Yes	134	12.2	113	11.5	14	18.7	7	20.6
No	199	18.2	156	15.8	27	36.0	16	47.1
NA	763	69.6	718	72.8	34	45.3	11	32.4
Intention to quit in next 12 mo
Yes	129	11.8	103	10.4	16	21.3	10	29.4
No	204	18.6	166	16.8	25	33.3	13	38.2
NA	763	69.6	718	72.8	34	45.3	11	32.4
Lifetime GAIN substance use scale
Low	586	53.5	534	54.1	37	49.3	15	44.1
Moderate	324	29.6	291	29.5	21	28.0	12	35.3
High	186	17.0	162	16.4	17	22.7	7	20.6
Lifetime GAIN externalizing scale
Low	371	33.9	344	34.9	21	28.0	6	17.7
Moderate	303	27.7	273	27.7	18	24.0	12	35.3
High	422	38.5	370	37.5	36	48.0	16	47.1
Lifetime GAIN internalizing scale
Low	408	37.2	380	38.5	18	24.0	10	29.4
Moderate	320	29.2	284	28.8	25	33.3	11	32.4
High	368	33.6	323	32.7	32	42.7	13	38.2
Tobacco ad receptivity
Receptive to cigarette and any tobacco ad other than ENDS	254	23.2	231	23.4	15	20.0	8	23.5
Receptive to ENDS and any tobacco ad other than cigarettes	152	13.9	136	13.8	12	16.0	4	11.8
Receptive to both cigarettes and ENDS and any other products ad	426	38.9	373	37.8	35	46.7	18	52.9
Receptive to other product ad except for cigarettes or ENDS	69	6.3	64	6.5	5	6.7	0	0.0
Not receptive to any tobacco advertising	195	17.8	183	18.5	8	10.7	4	11.8
ENDS perceived harm compared with cigarettes
Less harmful	463	42.2	405	41.0	42	56.0	16	47.1
About the same	469	42.8	433	43.9	26	34.7	10	29.4
More harmful	68	6.2	61	6.2	3	4.0	4	11.8
Do not know	14	1.3	14	1.4	0	0.0	0	0.0
Have not heard of e-cigarettes	82	7.5	74	7.5	4	5.3	4	11.8
Cigarette perceived harm
Low	31	2.8	23	2.3	4	5.3	4	11.8
Moderate	117	10.7	100	10.1	10	13.3	7	20.6
High	948	86.5	864	87.5	61	81.3	23	67.7
Nicotine dependence, median	1096	0.0	987	0.0	75	9.4	34	14.1
Outcome variable (wave 3)
Mean change in number of days smoked cigarettes in previous 30 d, wave 2 to wave 3	1096	0.04	987	0.05	75	−0.4	34	0.7
Mean change in intensity of smoking cigarettes previous 30 d, wave 2 to wave 3	1096	−3.7	987	−5.0	75	1.3	34	22.6

Abbreviations: ENDS, electronic nicotine delivery system; GAIN, Global Appraisal of Individual Needs; GED, General Educational Development.

^{^a}

Population Assessment of Tobacco and Health Study data from wave 1 to wave 3. Analysis included wave 1 young adults (aged 18-24 years) with data for all 3 waves. Respondent age was calculated based on age at wave 1. Analytic sample included wave 1 ever cigarette smoker and never ENDS users (n = 1585) and had nonmissing data on wave 2 ENDS exposure and wave 3 data on change in number of days smoked between wave 2 and wave 3 (n = 1096). ENDS included e-cigarettes at wave 1, and e-cigarettes, e-cigars, e-pipes, and e-hookah at wave 2 and wave 3. All use definitions refer to any use that includes exclusive or poly use of ENDS. All estimates are unweighted.

^{^b}

Includes wave 1 ever cigarette users, never ENDS users and had nonmissing data on wave 2 ENDS exposure and wave 3 data on change in number of days smoked between wave 2 and wave 3.

^{^c}

Includes wave 1 ever cigarette users, wave 2 never ENDS user.

^{^d}

Includes wave 1 ever cigarette users, wave 2 new ENDS user who used ENDS on 1 to 5 days in the previous 30 days at wave 2.

^{^e}

Includes wave 1 ever cigarette users, wave 2 new ENDS user who used ENDS on 6 or more days in the previous 30 days at wave 2.

^{^f}

All estimates in this column have a denominator less than 50 except those with results of 0.0.

Table 1. Sociodemographic, Tobacco, and Other Substance Use Characteristics of the Unweighted Wave 1 Participants by Overall and by Wave 2 ENDS Unexposed and Exposed Groupsa.

Table 1. Sociodemographic, Tobacco, and Other Substance Use Characteristics of the Unweighted Wave 1 Participants by Overall and by Wave 2 ENDS Unexposed and Exposed Groups^a.