. 2022 Jan 11;24(7):994–1002. doi: 10.1093/ntr/ntac008

Table 3.

Regression Analysis Results for Week 6 Outcomes

	t	p	95% CI	Unstandardized B	Unstandardized SE	β	ΔF	df	p	ΔR2
Cigarettes smoked^a
Marijuana use^a^,^b	0.247	.805	−10.628, 13.654	1.513	6.124	0.023	0.061	1, 107	.805	0.000
Gender	−0.454	.651	−14.822, 9.296	−2.763	6.083	−0.042
Site	1.563	.121	−3.155, 26.640	11.743	7.515	0.176
Age	2.200	.030	0.064, 1.239	0.652	0.296	0.251
Cigarettes smoked at baseline^a	3.541	.001	0.104, 0.369	0.236	0.067	0.316
Other combustible tobacco products^a^,^c	−0.377	.707	−16.113, 10.966	−2.573	6.830	−0.034
E-cigarette substitution
Marijuana use^a^,^b	−1.080	.282	−0.208, 0.061	−0.073	0.068	−0.104	1.167	1, 107	.282	0.010
Gender	0.320	.750	−0.112, 0.155	0.022	0.068	0.031
Site	−0.337	.737	−0.193, 0.137	−0.028	0.083	−0.040
Age	−2.019	.046	−0.013, 0.000^g	−0.007	0.003	−0.243
Cigarettes smoked at baseline^a	−1.743	.084	−0.003, 0.000^h	−0.001	0.001	−0.164
Other combustible tobacco products^a^,^c	0.089	.929	−0.144. 0.157	0.007	0.076	0.009
Carbon monoxide, ppm
Marijuana use at week 6^a^,^d	3.460	.001	1.894, 6.979	4.437	1.282	0.270	11.969	1, 107	.001	0.066
Gender	−1.058	.293	−3.782, 1.150	−1.316	1.244	−0.084
Site	−2.491	.014	−6.935, −0.789	−3.862	1.550	−0.241
Age	−1.216	.227	−0.198, 0.047	−0.075	0.062	−0.121
Cigarettes smoked at week 6^a	7.041	<.001	0.095, 0.170	0.132	0.019	0.550
Other combustible tobacco products^a^,^c	−1.630	.106	−5.052, 0.492	−2.280	1.398	−0.127
Respiratory symptoms^e
Marijuana use^a^,^f	1.102	.273	−1.062, 3.717	1.327	1.205	0.090	1.214	1, 104	.273	0.007
Gender	−0.910	.365	−3.489, 1.292	−1.097	1.205	−0.077
Site	0.505	.615	−2.232, 3.756	0.762	1.510	0.052
Age	1.478	.143	−0.030, 0.206	0.088	0.060	0.154
Cigarettes smoked at baseline^a	−2.603	.011	−0.063, −0.009	−0.036	0.014	−0.209
Other combustible tobacco products^a^,^c	−0.560	.576	−3.556, 1.989	−0.783	1.398	−0.047
Respiratory symptoms at baseline^e	7.074	<.001	0.373, 0.664	0.519	0.073	0.593

Boldface indicates statistical significance (p < .05). CI = confidence interval.

^aPast 7-day Timeline Followback (TLFB).

^bDichotomized into marijuana use reported at the baseline, week 2, or week 6 visit, or no marijuana use.

^cOther combustible tobacco products include little cigars, cigarillos, hand-rolled cigarettes, full-sized cigars, pipes, bidis, and hookah/water pipes.

^dDichotomized into combustible marijuana use at week 6 visit, or no combustible marijuana use (blunts, joints, spliffs, bowls, pipe/bong with marijuana and tobacco, and hookah with marijuana and tobacco).

^eMeasured with the American Thoracic Society Questionnaire, range 0–32, with higher scores indicating increased respiratory symptoms.

^fDichotomized into combustible marijuana use reported at the baseline, week 2, or week 6 visit, or no combustible marijuana use (blunts, joints, spliffs, bowls, pipe/bong with marijuana and tobacco, and hookah with marijuana and tobacco).

^g−0.000119.

^h0.000178.