The association between single and dual use of cannabis and alcohol and driving under the influence and riding with an impaired driver in a large sample of Canadian adolescents

Figures & data

Figure 1. Percentage of students who reported exclusive alcohol impaired driving or riding with an alcohol-impaired driver (alcohol-IDR), exclusive cannabis-IDR (cannabis-IDR), both alcohol- and cannabis-impaired-IDR (alcohol-cannabis-IDR) and were unsure if they have experienced either alcohol or cannabis-IDR.

Figure 2. Percentage of students who reported exclusive alcohol and/or cannabis impaired driving or riding with an impaired driver (IDR) or were unsure if they have experienced either alcohol- and/or cannabis-IDR by reported substance use.

Table 1. Adjusted odds ratios for engaging in exclusive alcohol-IDR, exclusive cannabis-IDR, and alcohol-cannabis-IDR, 2021–22 COMPASS study.

	Drove under the influence or rode with a driver under influence of
	Exclusive alcohol-IDR* (n = 5,245)	Exclusive cannabis-IDR (n = 2,246)	Alcohol-cannabis-IDR** (n = 2,803)
Substance use (none as ref)
Alcohol only	2.72 (2.36, 3.14)‡	2.02 (1.57, 2.61)	3.91 (3.19, 4.78)
Cannabis only	1.40 (0.91, 2.15)	11.84 (8.73, 16.03)	11.53 (8.72, 15.26)
Dual use	2.70 (2.06, 3.53)	12.76 (9.96, 16.35)	20.85 (13.52, 29.78)
Gender
Cisgender girl
Alcohol only	2.87 (2.54, 3.26)	2.35 (1.86, 2.98)	4.18 (3.33, 5.25)
Cannabis only	1.36 (0.75, 2.46)	13.54 (9.20, 19.94)	12.87 (8.34, 19.86)
Dual use	2.99 (2.28, 3.90)	14.95 (11.41, 19.58)	11.94 (4.88, 21.00)
Cisgender boy
Alcohol only	2.90 (2.51, 3.35)	2.61 (1.96, 3.47)	4.55 (3.42, 6.04)
Cannabis only	0.98 (0.48, 2.01)	15.42 (10.08, 23.59)	18.01 (11.62, 27.92)
Dual use	3.38 (2.46, 4.64)	19.03 (13.81, 26.23)	34.09 (20.42, 52.39)
Gender diverse
Alcohol only	2.48 (1.64, 3.75)	1.16 (0.54, 2.51)	3.56 (2.13, 5.94)
Cannabis only	1.89 (0.71, 5.03)	9.17 (4.54, 18.50)	11.00 (5.72, 21.20)
Dual use	1.84 (0.85, 4.00)	6.65 (3.31, 13.36)	14.29 (1.35, 35.08)
Age
15 years old or younger
Alcohol only	2.76 (2.34, 3.25)	1.97 (1.37, 2.85)	4.84 (3.71, 6.31)
Cannabis only	1.38 (0.78, 2.43)	13.31 (8.94, 19.83)	17.07 (11.54, 25.24)
Dual use	2.84 (2.01, 4.03)	12.95 (9.02, 18.60)	20.94 (18.91, 46.70)
16 years old or older
Alcohol only	2.55 (1.92, 3.40)	2.14 (1.52, 3.02)	3.03 (2.22, 4.14)
Cannabis only	1.35 (0.73, 2.48)	9.35 (6.36, 13.75)	7.77 (5.20, 11.62)
Dual use	2.74 (1.86, 4.03)	12.42 (9.18, 16.81)	16.26 (10.08, 24.33)

* IDR: impaired driving or riding with an impaired driver.

**Alcohol-cannabis-IDR: both alcohol- and cannabis-IDR.

^‡ Significant odds ratios at p < 0.05 are bolded.

Table 2. Adjusted odds ratios for engaging in exclusive alcohol-IDR, exclusive cannabis-IDR, and alcohol-cannabis-IDR among a subgroup of adolescents who reported monthly substance use, 2021–22 COMPASS study.

	Exclusive alcohol-IDR* (n = 5,245)	Exclusive cannabis-IDR (n = 2,246)	Alcohol-cannabis-IDR (n = 2,803)
Overall
Dual vs alcohol-only use (ref.)	1.03 (0.85, 1.25)	6.11 (4.99, 7.47)	9.51 (8.28, 10.92)
Dual vs cannabis-only use (ref.)	2.00 (1.41, 2.84)*	1.08 (0.86, 1.35)	2.99 (2.44, 3.66)
Gender
Cisgender girl
Dual vs exclusive alcohol use	1.08 (0.91, 1.30)	6.26 (5.25, 7.48)	7.30 (6.23, 8.55)
Dual vs exclusive cannabis use	2.61 (1.62, 4.20)	1.02 (0.79, 1.30)	2.21 (1.66, 2.96)
Cisgender boy
Dual vs exclusive alcohol use	1.16 (0.95, 1.43)	6.69 (5.45, 8.20)	10.79 (9.04, 12.88)
Dual vs exclusive cannabis use	3.15 (1.79, 5.56)	1.16 (0.89, 1.52)	3.31 (2.46, 4.46)
Gender diverse
Dual vs exclusive alcohol use	0.94 (0.54, 1.63)	6.01 (3.40, 10.63)	10.20 (6.98, 14.90)
Dual vs exclusive cannabis use	0.84 (0.37, 1.91)	1.04 (0.59, 1.85)	2.94 (1.78, 4.80)

* Significant odds ratios at p < 0.05 are bolded.