Table 2.

Percent of Concordant and Discordant Responses to the Questions Assessing Lifetime Electronic Cigarette (E-Cigarette) Use and Lifetime Use of One or More E-Cigarette Devices

	Concordant	Discordant	Kappa	95% CI
Total sample	83.2	16.8	0.67	(0.63–0.70)
Lifetime vapers	68.5	31.5	—
Sex
Female	63.2	36.8	0.61	(0.56–0.66)
Male	74.4	25.6	0.73	(0.69–0.77)
Race
Nonwhite	58.5	41.5	0.58	(0.53–0.63)
White	77.3	22.7	0.74	(0.70–0.78)
Lifetime product use
Traditional tobacco products
No	57.2	42.8	0.64	(0.58–0.69)
Yes	73.9	26.1	0.39	(0.31–0.47)
Disposable, cig-a-like, or E-hookah
No	63.0	37.0	0.64	(0.60–0.68)
Yes	85.6	14.4	—
Vape pen or Ego
No	58.4	41.6	0.64	(0.59-0.68)
Yes	76.5	23.5	—
JUUL
No	49.7	50.3	0.59	(0.50–0.67)
Yes	71.6	28.4	—
Other pod-based system
No	55.5	44.5	0.60	(0.56–0.65)
Yes	80.6	19.4	—
Mods or APVs
No	62.0	38.0	0.66	(0.62–0.70)
Yes	75.1	24.9	—

APV = advanced personal vaporizers, CI = confidence interval.