Table 1.

Sample demographics among current e-cigarette users in 2017–2019

	2017	2018	2019
	N=579	N=1077	N=914
Female (%)	49.8%	52.4%	55.4%
Age (M, SD)	16.3 (1.2)	16.2 (1.2)	16.2 (1.3)
Age first trying e-cigarettes (M, SD)	14.6 (1.7)^a	14.3 (1.8)^b	14.1 (1.8)^c
Non-Hispanic White (%)	71.3%^a	63.1%^b	60.2%^b
SES (M, SD range 1–9)	6.8 (1.7)^a	6.6 (1.7)^b	6.6 (1.8)^b
Total e-cig devices used in past month (M, SD)	1.8 (0.9)^a	2.2 (1.2)^b	2.0 (1.1)^c
Current use of more than one e-cig device (%)	53.0%^a	63.8%^b	59.6%^b

Note:

^a,b,c

Columns with different superscripts indicate column proportions that differ significantly from one another, p<.05.