Table 2.

Vaping dependence and smoking dependence measures among adult AI dual EC and cigarette users (N = 44)

Vaping Dependence Measures		%	Smoking Dependence Measures			%
Minutes after waking use first EC			Minutes after waking use first cigarette
5 or less		31%	5 or less			24%
6–30		24%	6–30			31%
31–120		24%	31–120			38%
121+		21%	121+			7%
Nights per week wake to use EC			Nights per week wake to smoke
Never/less than weekly		73%	Never/less than weekly			54%
1 to 2		12%	1 to 2			23%
3 or more		15%	3 or more			23%
Continue using EC because hard to quit			Continue to smoke because hard to quit
Yes		44%	Yes			80%
No		56%	No			20%
Ever have strong cravings to use EC			Ever have strong cravings to smoke
Yes		33%	Yes			84%
No		67%	No			16%
How strong were urges to vape, past week			How strong were urges to smoke in past week
None		44%	None			0%
Slight		34%	Slight			18%
Moderate		10%	Moderate			25%
Very/extremely strong		22%	Very/extremely strong			57%
Hard to keep from using EC			Hard to keep from smoking
Yes		36%	Yes			58%
No		64%	No			42%
WHEN HAVE NOT USED [EC; tobacco] for a while OR when you tried to stop [vaping; smoking] …
Irritable because can’t use EC			Irritable because can’t smoke
Yes		32%	Yes			73%
No		68%	No			27%
Nervous because can’t vape			Nervous because can’t smoke
Yes		32%	Yes			66%
No		68%	No			34%
Composite Dependence Scores						p-value*
Heaviness of Vaping Index [32]	Mean (SD)	2.07 (1.76)	Heaviness of Smoking Index [33]	Mean (SD)	2.36 (1.66)	.2155
PSDI-EC [32]	Mean (SD)	6.42 (4.84)	PSDI-smoking [32]	Mean (SD)	11.02 (5.00)	<.0001

EC Electronic Cigarette

PSDI Penn State Dependence Index

Missing = 10 for Heaviness of Vaping Index, 12 for PSDI-EC, 2 for Heaviness of Smoking Index, and 3 for PSDI-smoking

*Paired t-test on the differences between the vaping dependence scores and smoking dependence scores