Table 2.

Univariable and multivariable extended Cox regression analyses of the relationship between methamphetamine use and methadone discontinuation (n = 875).

	Methadone discontinuation
Characteristics	HR (95 % CI)	aHR (95 % CI)
Methamphetamine use*
No use	Reference
No more than weekly use	1.49 (1.08–2.04)	1.06 (0.77–1.45)
More than weekly use	2.17 (1.63–2.88)	1.38 (1.03–1.85)
New initiate	3.32 (2.56–4.33)	2.67 (2.04–3.48)
Age (per year)	0.95 (0.94–0.96)	0.96 (0.95–0.98)
Male	0.90 (0.70–1.16)
White	0.70 (0.54–0.90)	0.69 (0.54–0.89)
Living in the DTES*	1.56 (1.20–2.02)	1.23 (0.94–1.61)
HIV positive	0.98 (0.76–1.26)
Homelessness*	2.44 (1.85–3.21)	1.55 (1.16–2.07)
≥Daily illicit opioid use*, †	2.49 (1.97–3.15)	1.63 (1.28–2.08)
≥Daily cocaine/crack use*	0.86 (0.63–1.18)
≥Daily alcohol use*	1.01 (0.66–1.55)
Incarceration*	1.41 (0.85–2.33)

HR: hazard ratio. aHR: adjusted hazard ratio. CI: confidence interval. DTES: Downtown Eastside.

^*Denotes behaviours/events in the past six months.

^†The variable of illicit opioid use was lagged to a prior study follow-up visit.