Is marijuana use associated with decreased use of prescription opioids? Toxicological findings from two US national samples of drivers

Table 1 Characteristics of the study samples, 2011–2016 Fatality Analysis Reporting System (FARS) and 2013–2014 National Roadside Survey of Alcohol and Drug Use by Drivers (NRS)

Characteristic	FARS^a (n = 47,602) %	NRS^b (n = 7881) %^c
Age (years)
15–24	21.6	28.1
25–39	30.5	33.4
40–64	37.0	33.2
≥ 65	10.9	5.3
Sex
Male	77.7	56.6
Female	22.3	43.4
Race/ethnicity
Non-Hispanic White	83.8	61.0
Non-Hispanic Black	11.5	25.7
Other	4.7	13.2
Geographic region
South	43.8	41.1
Midwest	21.8	20.5
Northeast	11.3	17.5
West	23.1	20.9
Testing positive for prescription opioids
No	93.1	95.5
Yes	6.9	4.5
Testing positive for marijuana
No	84.3	92.1
Yes	15.7	7.9
Testing positive for alcohol
No	58.0	94.7
Yes	42.0	5.3

^aThere were 7 drivers with missing data on gender and 4616 on race from the FARS
^bThere were 204 drivers with missing data on age, 106 on gender, and 89 on race from the NRS
^cPercentage of drivers weighted for the US driver population

ISSN: 1747-597X