Table 3.

Question Revisions Based on Retrieval Process Issues

Issue	Original question	Discussion	Revised final question
Retrieval Process: Issues with frequency of ENDS use	During the last 30 days, have you used a disposable e-cigarette or an e-cigarette with a disposable cartridge? Neither requires the addition of e-liquid/e-juice.	“If I add up all the times I’ve done it, it could add up to one.”	No change.
	During the past 30 days, have you smoked a vape pen, personal vaporizer, or any other device that requires the addition of e-liquid/e-juice?	“I do it so casually, that I don’t really recall how many days.”	No change.
	On how many of the last 30 days have you used such a product?	“I just thought that I’ve only done it with friends, so I know it was then. I don’t use it as much [as cigarettes].”	No change.
		“I’ve only used it once and it was [with] my friends.”
Retrieval Process: Issues with quantity of ENDS consumed	What was the size of the bottle in milliliters (ml) from which you obtained your e-liquid/e-juice in the last month?	“I don’t pay attention that much to the size of it.”	Cut.
		“I’m with a friend and they just used the bottle; we smoked as much as we could, like a big group.”
		“I don’t even pay attention to how many milliliters it is; there is small, medium, large, and the extra-large one. It says the milliliters, but depending on the flavor and how much I like it, it will determine how big a bottle I buy.”	Cut.
	On the days you used the product in the last month, how many bottles of e-liquid/e-juice did you usually use per day?
		“I get sick of a flavor quickly, so I’ll buy quite a few. I mix my own flavors. I’ve used it for two months but I don’t know if I’ve used an entire bottle yet.”	Cut.
	On the days you used this device in the past month, approximately how many milliliters (ml) of e-liquid/e-juice did you consume on average in a given day? (≈20 drops = 1ml)
	How many bottles of e-liquid/e-juice did you use in the last 30 days?		Cut.

ENDS = electronic nicotine delivery systems.