. Author manuscript; available in PMC: 2011 Apr 1.

Published in final edited form as: Drug Alcohol Depend. 2010 Nov 13;114(2-3):233–236. doi: 10.1016/j.drugalcdep.2010.09.014

Table 2.

Incidence of transitions to injecting among former and never noninjecting heroin users by injecting history, San Antonio, 2002–2005.

	n	Number (%) of transitions to injecting	Person-years at risk	Incidence per 100 PYAR	95% CI	HR^a	95% CI	Adjusted HR^a	95% CI
All	266	63 (24)	282	22.3	17.2–28.2	na	na	na	na
Injection history
Never injectors	219	43 (20)	232.5	18.5	13.4–24.4	1.0	na	1.0	na
Former injectors	47	20 (43)	49.5	40.4	24.6–60.0	1.93^*	1.12–3.34	2.26^**	1.19–4.29

Adjusted for age, ever in drug treatment, HBV infected at baseline, years since starting heroin use and always used heroin intra-nasally in past 30 days.

p < 0.05.

^**

p < 0.01.