Table 4.

Concurrent substance use behavior among individuals using e-cigarettes (N = 8,755), by past 12-month NSSI.

	Past-year NSSI N = 2,901 (%)	No past-year NSSI N = 5,854 (%)	p
Conventional cigarette use			<0.0001
E-cig – Conv. Cig use	1,795 (61.9)	4,433 (75.7)
E-cig + Conv. Cig use	1,106 (38.1)	1,421 (24.3)
Marijuana use			<0.0001
E-cig – Marj. Use	903 (31.3)	2,760 (47.2)
E-cig + Marj. Cig	1,998 (68.9)	3,094 (52.8)
Alcohol use			0.7242
E-cig – Alc. use	539 (18.6)	1,058 (18.1)
E-cig + Alc. Use	2,361 (81.4)	4,796 (81.9)
Use of other substances			<0.0001
E-cig – Other Sub.	2,280 (78.6)	5,078 (86.8)
E-cig + Other Sub.	621 (21.4)	775 (13.2)
Number of substances used			<0.0001
E-cig use only	198 (6.8)	613 (10.5)
E-cig + 1–2 substances	1,746 (60.2)	4,131 (70.6)
E-Cig + 3–4 substances	926 (31.9)	1,081 (18.5)
E-Cig + 5+ substances	31 (1.1)	29 (0.5)