. Author manuscript; available in PMC: 2006 Aug 4.

Published in final edited form as: Addict Behav. 2006 May 4;31(6):962–983. doi: 10.1016/j.addbeh.2006.03.015

Table 5.

Can differences between drugs in length of time for progression to first problem (LOTIP) be accounted for by gender or number of parents with substance use disorders?

Regression model	Predictor	Beta weight	‘p’ for unique variance
Drug type only (R²=0.10; R =0.32; p <0.01)	Tobacco	−6.02	=0.05
	Cannabis	−15.21	<0.01
	Cocaine	−24.89	<0.01
	Opiates	−29.92	<0.01
Drug type plus gender/parents (R2=0.12; R =0.35; p <0.01)	Tobacco	−4.81	=0.13
	Cannabis	−14.67	<0.01
	Cocaine	−24.40	<0.01
	Opiates	−26.62	<0.01
	Gender (Female = 1)	−7.84	<0.01
	1 Parent with SUD	−2.61	=0.44
	2 Parents with SUD	−5.30	=0.09
	1 Parent with TUD	0.86	=0.80
	2 Parents with TUD	2.66	=0.41

Note: Referent group for drugs was alcohol. Referent group for parent substance use variables was having zero parents with SUD or TUD. Beta weights are unstandardized and indicate the mean number of months in time for transition associated with the predictor, compared to male users of alcohol with no parents having an SUD or TUD. SUD = any DSM-III-R abuse or dependence disorder excluding tobacco. TUD = tobacco use disorder (as measured by a score of 1 or greater on the Fagerstrom Test for Nicotine Dependence).