Table 2.

Unadjusted and adjusted hazard ratios for factors related to initiation of prescription opioid injection among people who use drugs in Vancouver (n= 1580).

Variable	Hazard Ratio (95% CI)*
	Unadjusted	p-value	Adjusted	p-value
Sex (Female vs. Male)	1.11 (0.86–1.44)	0.421
Age (Per year older)	1.00 (0.99–1.01)	0.654
Ethnicity (Caucasian vs. Non-Caucasian)	1.51 (1.16–1.96)	0.002	1.37 (1.04–1.79)	0.024
Education (≥ Sec. vs. < Sec.)	1.38 (1.07–1.77)	0.012	1.44 (1.12–1.87)	0.005
Follow-up Period (per 6-month interview interval)	0.95 (0.91–0.99)	0.008	0.97 (0.93–1.00)	0.063
Cohort
ACCESS (vs. ARYS)	1.26 (0.88–1.79)	0.207
VIDUS (vs. ARYS)	1.73 (1.25–2.40)	<0.001
Downtown Eastside Residency**	1.85 (1.42–2.40)	<0.001	1.31 (1.00–1.71)	0.047
Homelessness**	1.19 (0.91–1.56)	0.213
Incarcerated**	1.29 (0.91–1.84)	0.158
Addiction Treatment Enrolment**
Non-methadone treatment (vs. none)	1.20 (0.80–1.81)	0.383	1.16 (0.76–1.75)	0.498
Methadone treatment (vs. none)	4.46 (2.03–9.80)	<0.001	2.96 (1.34–6.51)	0.007
Methadone and non-methadone (vs. none)	2.45 (1.85–3.24)	<0.001	1.37 (1.03–1.82)	0.031
Drug Dealing**	1.76 (1.34–2.31)	<0.001	1.32 (1.00–1.76)	0.050
Sex work**	1.05 (0.68–1.64)	0.824
Heavy Alcohol Use**	0.78 (0.57–1.07)	0.121
Heroin Injection**	6.30 (4.83–8.20)	<0.001	4.39 (3.24–5.95)	<0.001
Heroin Non-injection**	1.54 (1.06–2.23)	0.023
Cocaine Injection**	2.23 (1.71–2.89)	<0.001	1.40 (1.06–1.84)	0.018
Crack/coc. Non-injection**	1.69 (1.25–2.28)	<0.001
Methamphetamine Injection**	2.16 (1.56–3.00)	<0.001	1.71 (1.22–2.39)	0.002
Methamphetamine Non-injection**	0.91 (0.64–1.30)	0.619
Prescription Opioid Non-injection**	1.94 (1.22–3.09)	0.005	1.99 (1.25–3.17)	0.004
Marijuana Use**	1.04 (0.80–1.35)	0.773
Sexual Abuse**	1.12 (0.84–1.49)	0.441
Suicide Attempt**	1.56 (0.85–2.87)	0.150

^*95% Confidence Interval.

^**In the previous six months (yes vs. no), lagged to the previous follow-up to prescription opioid injection initiation assessment.