Table 3. Multivariable logistic regression analyses of factors associated with recent exposure to fentanyl among people who inject drugs in Vancouver, Canada, June – October 2016 (n = 452).

Variable	Adjusted Odds Ratio	95% Confidence Interval	p-value
Model 1 (UDS results)
Age
(per year older)	0.96	(0.94 – 0.99)	0.006
UDS positive for:
Morphine/heroin
(yes vs. no)	6.73	(3.64 – 13.53)	<0.001
Buprenorphine
(yes vs. no)	4.25	(1.77 – 10.13)	0.006
Cocaine
(yes vs. no)	2.92	(1.81 – 4.83)	<0.001
Amphetamine/methamphetamine
(yes vs. no)	3.26	(2.01 – 5.42)	<0.001
Cannabis
(yes vs. no)	0.52	(0.31 – 0.83)	0.026
Model 2 (self-reported drug use in the past 6 months)
Age
(per year older)	0.97	(0.95 – 0.98)	0.002
Heroin use*
(yes vs. no)	9.19	(4.19 – 24.71)	<0.001
Fentanyl pills or patches use*†
(yes vs. no)	1.83	(0.94 – 3.49)	0.126
Cannabis use*
(yes vs. no)	0.46	(0.30 – 0.70)	0.002

UDS: urine drug screen.

^*Denotes behaviours and events in the previous six months.

^†Non-medical use.