Table 1

Log cotinine: concentration index

	(1)	(2)	(3)
	Sample	Non-smokers	Smokers
	Coefficient/ SE	Coefficient/ SE	Coefficient/ SE
Treatment	0.0265	0.2097**	−0.0285
Treatment	(0.0693)	(0.0910)	(0.0182)
Time	0.0005	−0.0015*	0.0003^∗∗
Time	(0.0005)	(0.0008)	(0.0001)
Treatment × Time	−0.0009	0.0007	−0.0003
Treatment × Time	(0.0008)	(0.0011)	(0.0002)
Constant	−0.1501***	−0.2329***	0.0119
Constant	(0.0394)	(0.0559)	(0.0127)
N	3718	2952	766
R²	0.0009	0.0029	0.0076

*p<0.10, ^∗∗p<0.05, ^∗∗∗ p<0.01.