. Author manuscript; available in PMC: 2014 May 1.

Published in final edited form as: Subst Use Misuse. 2013 Apr 12;48(7):513–522. doi: 10.3109/10826084.2013.787091

Table 1. Differences on smoking and other drug use among trajectory groups.

	Nonpersistent light smokers, N = 26			Nonpersistent moderate smokers, N = 36			Persistent moderate smokers, N = 94			Persistent heavy smokers, N = 59

Variables	M		SD	M		SD	M		SD	M		SD
Before conception:
# cigarettes/day	0.50^a		0.75	9.15^b		4.53	7.78^c		3.33	21.21^d		5.21
# drinks/day	0.25^a		0.58	1.04		1.98	0.39		0.84	1.27^b		3.22
# joints/day	0.50		1.59	0.85		1.34	1.33		2.54	1.23		2.32
First trimester
# cigarettes/day	0.25^a		0.51	3.62^b		2.45	5.97^c		2.77	15.17^d		5.15
# drinks/day	0.11		0.32	0.31		0.83	0.15		0.28	0.37		0.73
# joints/day	0.28		0.78	0.38		0.77	0.94		1.96	0.79		1.53
Second trimester
# cigarettes/day	.00^a		.00	.13^a		.35	3.91^b		2.79	8.18^c		5.54
# drinks/day	.00		.00	.00		.00	.01		.02	.01		.02
# joints/day	.07		.35	.04		.13	.17		.51	.19		.57
Third trimester
# cigarettes/day	.04^a		.16	.00^a		.01	3.17^b		2.35	8.50^c		6.96
# drinks/day	.00		.02	.00		.02	.00		.01	.01		.03
# joints/day	.02		.10	.02		.11	.07		.29	.11		.47
Positive saliva cotinine		35%			36%			96%			98%
Positive meconium		41%			27%			86%			93%

Note. Means with different superscripts were significantly different from each other.