Table 2.

Association of Non-cigarette Tobacco Product Ever Use With Subsequent Cigarette Use in Overall Sample, Population Assessment of Tobacco, and Health Study, 2013–2018 (n = 29 788)^a

	Cigarette ever use		Cigarette past-30-day use
Use at exposure wave b	Weighted, unadjusted cigarette ever use, %c	OR (95% CI)d	Weighted, unadjusted cigarette past 30-d use, %c	OR (95% CI)d
E-cigarette
Never	3.2	1 [Reference]	1.5	1 [Reference]
Ever	17.2	2.76 (2.21–3.45)	8.8	2.72 (2.00–3.68)
Cigar
Never	3.8	1 [Reference]	1.8	1 [Reference]
Ever	20.4	2.00 (1.42–2.80)	10.9	1.91 (1.19–3.07)
Other
Never	3.5	1 [Reference]	1.6	1 [Reference]
Ever	15.2	1.66 (1.28–2.14)	8.1	1.83 (1.26–2.65)

e-cigarette, electronic cigarette; OR, odds ratio; CI, confidence interval.

^aPerson-interval count. Intervals included respondents with data for at least two consecutive exposure wave and outcome waves, creating the potential for up to three time-varying within-person observations per respondent (W1-W2, W2-W3, W3-W4).

^bExposure wave is defined as the first wave within each specific interval. Youths were considered to have prior non-cigarette tobacco use if they started using e-cigarettes, cigars, or other non-cigarette tobacco products prior to interval exposure wave.

^cPercentages were weighted using the most recent sample weight available per person. Guidelines for the Restricted-Use Files of the Population Assessment of Tobacco and Health Study prohibit the reporting of cell counts.

^dRegression models were adjusted for sex, age, race/ethnicity, parental education level (bachelors or higher), ever alcohol use, ever marijuana use, ever prescription drug abuse, interval, and cigarette susceptibility.