Table 2.

Unadjusted and Adjusted Logistic Regression of the Association Between Baseline Anxiety and Retention in Assigned Opioid Agonist Therapy at Week 24 of the OPTIMA Trial.

Variable	Unadjusted		Adjusted
	Odds ratio (95% CI)	P-value	Odds ratio (95% CI)	P-value
Anxiety status (BAI ≥ 16 vs. <16)	0.88 (0.51–1.54)	0.656	2.03 (0.94–4.40)	0.073
Buprenorphine versus methadone	0.58 (0.34–0.99)	0.048	0.38 (0.18–0.78)	0.008
Alberta versus British Columbia	1.64 (0.54–5.59)	0.395	1.72 (0.50–5.89)	0.386
Ontario versus British Columbia	4.64 (1.63–15.31)	0.006	3.22 (0.91–11.41)	0.07
Quebec versus British Columbia	26.84 (10.31–84.88)	<0.001	23.72 (6.96–80.82)	<0.001
Lifetime heroin use (yes vs. no)	0.49 (0.28–0.86)	0.012	0.88 (0.38–2.03)	0.762
Age (per year older)	1.02 (1.00–1.05)	0.086	1.02 (0.99–1.05)	0.273
Gender identity (man vs. woman, transgender, or other)	2.03 (1.14–3.74)	0.020	2.81 (1.26–6.30)	0.012
Ethnicity (white vs. Black, Indigenous, and people of colour)	2.47 (1.33–4.79)	0.005	0.71 (0.30–1.68)	0.438
Housing (unstable vs. stable)	0.44 (0.25–0.77)	0.004	0.60 (.28–1.28)	0.19
Education (high school vs. other)	0.63 (0.33–1.23)	0.167
OUD severity (severe vs. mild-to-moderate)	2.02 (0.32–39.07)	0.524
OAT history (ever vs. never)	0.42 (0.25–0.72)	0.002	1.14 (0.52–2.51)	0.743
BPI, pain severity score (per 1 point higher)	1.02 (0.93–1.12)	0.706
BPI, pain interference score (per 1 point higher)	0.98 (0.91–1.06)	0.680
UDT (positive for opioids)	5.45 (1.06–99.83)	0.105
UDT (positive for stimulants)	0.17 (0.09–0.30)	<0.001	0.40 (0.17–0.91)	0.028
UDT (positive for cannabinoids)	1.11 (0.65–1.89)	0.703
UDT (positive for benzodiazepines)	1.72 (0.83–3.47)	0.133
Alcohol intoxication (in the last 30 days)	1.96 (0.99–3.82)	0.049	1.10 (0.44–2.72)	0.844

Note. BAI = Beck Anxiety Inventory; BPI = brief pain inventory; OAT = opioid agonist therapy; OUD = opioid use disorder; UDT = urine drug test. P-values <0.05 are marked in bold.