Table 4.

Summary of effect size (R2 coefficient and Cohen d) on nicotine emission per puff by device power, e-liquid nicotine concentration, and nicotine (cigarette and/or ENDS^a) use history

Factors		R2 coefficient	Cohen db
Device power		0.042	0.666c
Nicotine concentration		0.422	N/Ad
Cigarette smoking history		0.246
	Yes versus no		1.228
	Yes versus did not respond		1.078
Years of ENDS use		0.351
	>10 years versus 6 months to 1 year		2.432
	>10 years versus 1-5 years		2.190
	>10 years versus 6-10 years		1.410
	6-10 years versus 6 months to 1 year		1.022
	6-10 years versus 1-5 years		0.781

^aENDS: electronic nicotine delivery system.

^bOnly medium to large effect size (Cohen d≥0.5) is presented.

^cMedium power versus low power.

^d“N/A” denotes “not applicable” or small effect size (Cohen d<0.5).