Effects of minimum legal drinking age on alcohol and marijuana use: evidence from toxicological testing data for fatally injured drivers aged 16 to 25 years

Table 3 Estimated relative risks of alcohol and marijuana use in fatally injured drivers 1999–2010 associated with MLDA, adjusting for covariates

Covariate	Drug	RR	95% confidence interval
Vehicle occupants (N = 6,337^a)	Alcohol only	1.13	1.01 to 1.26
	Marijuana only	0.78	0.53 to 1.16
	Alcohol and marijuana	1.21	0.87 to 1.70
Sex (N = 7,191)	Alcohol only	1.13	1.01 to 1.26
	Marijuana only	0.75	0.53 to 1.08
	Alcohol and marijuana	1.22	0.90 to 1.65
Number of deaths (N = 7,191)	Alcohol only	1.14	1.02 to 1.28
	Marijuana only	0.76	0.53 to 1.10
	Alcohol and marijuana	1.22	0.90 to 1.66
Race (N = 6,475^b)	Alcohol only	1.14	1.01 to 1.28
	Marijuana only	0.77	0.52 to 1.13
	Alcohol and marijuana	1.30	0.95 to 1.80
Year (N = 7,191)	Alcohol only	1.14	1.02 to 1.28
	Marijuana only	0.75	0.52 to 1.07
	Alcohol and marijuana	1.21	0.90 to 1.64
State (N = 7,191)	Alcohol only	1.14	1.02 to 1.27
	Marijuana only	0.75	0.53 to 1.08
	Alcohol and marijuana	1.19	0.88 to 1.61
Hispanic ethnicity (N = 6,475^b)	Alcohol only	1.14	1.01 to 1.28
	Marijuana only	0.78	0.53 to 1.14
	Alcohol and marijuana	1.30	0.95 to 1.79
State allows medical use of marijuana (N = 7,191)	Alcohol only	1.14	1.02 to 1.28
	Marijuana only	0.77	0.54 to 1.10
	Alcohol and marijuana	1.22	0.90 to 1.65
All covariates (N = 5,848^c)	Alcohol only	1.12	0.99 to 1.26
	Marijuana only	0.80	0.53 to 1.21
	Alcohol and marijuana	1.24	0.87 to 1.75

^a854 missing data points.
^b716 missing data points.
^cListwise deletion for missing data on vehicle occupants and race rendered 1,343 missing data points.

ISSN: 2197-1714