Table 2

Prevalence of substance use

OR (95% CI)
SubstancePrevalence (95% CI)Male (vs female)Age < 30 (vs > 30)Single vehicle (vs multivehicle)Night (vs day)Weekend (vs weekday)Admitted (vs discharged)
Alcohol
 BAC >0.01%17.8 (15.6 to 20.1)3.26 (2.17 to 5.01)3.64 (2.61 to 5.08)6.99 (4.91 to 10.06)12.45 (8.23 to 18.84)3.97 (2.84 to 5.56)1.89 (1.35 to 2.64)
 BAC > 0.08%15.4 (13.4 to 17.7)3.42 (2.20 to 5.49)3.77 (2.65 to 5.37)6.91 (4.74 to 10.21)15.25 (9.46 to 24.58)3.89 (2.74 to 5.57)1.82 (1.28 to 2.60)
Cannabis
 Δ-9-THC >0.2 ng/mL7.3 (5.9 to 9.0)2.17 (1.23 to 4.02)2.29 (1.40 to 3.70)1.64 (1.00 to 2.65)0.73 (0.45 to 1.18)1.04 (0.62 to 1.72)1.43 (0.86 to 2.35)
 Δ-9-THC >3 ng/mL*3.0 (2.1 to 4.2)2.11 (0.88 to 5.82)2.73 (1.28 to 5.85)0.72 (0.29 to 1.61)1.36 (0.62 to 3.14)0.84 (0.35 to 1.85)1.23 (0.53 to 2.69)
 THC-COOH >1 ng/mL12.6 (10.7 to 14.7)2.19 (1.42 to 3.48)2.35 (1.61 to 3.45)2.13 (1.46 to 3.11)0.52 (0.36 to 0.76)1.20 (0.81 to 1.75)1.57 (1.06 to 2.32)
Other drugs
 Cocaine >1 ng/mL2.8 (2.0 to 4.0)1.62 (0.69 to 4.24)0.72 (0.26 to 1.74)2.10 (0.96 to 4.62)1.41 (0.64 to 3.07)1.85 (0.84 to 4.04)2.70 (1.23 to 5.93)
 Cocaine >24 ng/mL*1.2 (0.7 to 2.0)3.10 (0.67 to 28.94)1.10 (0.25 to 3.99)2.27 (0.65 to 8.23)1.74 (0.50 to 6.33)2.28 (0.65 to 8.27)2.12 (0.58 to 7.43)
 Cocaine or metabolites7.2 (5.8 to 8.9)1.71 (0.99 to 3.04)1.48 (0.89 to 2.45)2.33 (1.43 to 3.81)1.53 (0.94 to 2.50)1.42 (0.86 to 2.32)2.44 (1.49 to 3.98)
 Amphetamine >1 ng/mL1.2 (0.7 to 2.0)1.26 (0.35 to 5.63)1.56 (0.40 to 5.46)2.27 (0.65 to 8.23)5.04 (1.29 to 28.66)0.58 (0.10 to 2.26)1.09 (0.24 to 3.94)
 Amphetamine >41 ng/mL*0.6 (0.3 to 1.3)1.40 (0.23 to 14.75)3.34 (0.56 to 22.90)2.58 (0.43 to 17.72)3.74 (0.61 to 39.44)0.77 (0.07 to 4.74)1.84 (0.27 to 10.97)
 Methamphetamine >1 ng/mL1.2 (0.7 to 2.0)1.26 (0.35 to 5.63)1.56 (0.40 to 5.46)2.27 (0.65 to 8.23)5.04 (1.29 to 28.66)0.58 (0.10 to 2.26)1.54 (0.39 to 5.38
 Methamphetamine >45 ng/mL*1.2 (0.7 to 2.0)1.26 (0.35 to 5.63)1.56 (0.40 to 5.46)2.27 (0.65 to 8.23)5.04 (1.29 to 28.66)0.58 (0.10 to 2.26)1.54 (0.39 to 5.38
 Any amphetamine†2.3 (1.5 to 3.3)1.79 (0.68 to 5.52)2.34 (0.96 to 5.63)3.53 (1.45 to 9.15)2.70 (1.11 to 7.00)1.30 (0.52 to 3.12)0.95 (0.33 to 2.42)
 Any amphetamine > limit1.9 (1.3 to 2.9)1.80 (0.63 to 6.35)2.79 (1.06 to 7.41)3.20 (1.22 to 9.00)3.80 (1.38 to 12.07)1.46 (0.54 to 3.82)0.76 (0.22 to 2.20)
 Morphine > 1 ng/mL‡2.3 (1.5 to 3.4)1.29 (0.50 to 3.74)0.52 (0.13 to 1.58)2.23 (0.89 to 5.66)0.98 (0.37 to 2.45)1.05 (0.38 to 2.66)3.40 (1.35 to 8.63)
 Morphine >24 ng/mL*1.8 (1.1 to 2.8)1.47 (0.49 to 5.30)0.71 (0.17 to 2.28)2.56 (0.90 to 7.53)0.97 (0.32 to 2.76)0.75 (0.21 to 2.26)3.09 (1.07 to 8.89)
 Any illicit drug§10.0 (8.4 to 11.9)1.55 (0.99 to 2.49)1.41 (0.91 to 2.18)2.90 (1.91 to 4.43)1.55 (1.03 to 2.35)1.33 (0.86 to 2.02)2.33 (1.53 to 3.54)
 Any illicit drug >limit4.3 (3.2 to 5.7)2.12 (1.02 to 4.84)1.43 (0.73 to 2.72)2.98 (1.58 to 5.74)2.07 (1.10 to 3.95)1.33 (0.69 to 2.50)1.55 (0.80 to 2.94)
Medications (> 1 ng/mL)§ Age <50 (vs >50)§
 Diphenhydramine¶4.7 (3.5 to 6.2)2.02 (0.97 to 4.62)0.89 (0.47 to 1.76)2.46 (1.30 to 4.70)0.86 (0.44 to 1.65)1.03 (0.52 to 1.98)3.87 (2.04 to 7.46)
 Benzodiazepines**4.0 (2.9 to 5.3)1.26 (0.63 to 2.68)1.34 (0.66 to 2.92)3.41 (1.74 to 6.91)1.70 (0.87 to 3.33)1.11 (0.54 to 2.19)3.14 (1.61 to 6.17)
 Z-drugs (zopiclone, zolpidem)0.6 (0.3 to 1.3)0.74 (0.12 to 51.0)0.71 (0.12 to 4.86)2.58 (0.43 to 17.72)1.11 (0.16 to 6.62)0.32 (0.01 to 2.66)3.29 (0.55 to 22.59)
 Antidepressants6.5 (5.2 to 8.1)0.52 (0.31 to 0.87)0.59 (0.35 to 0.99)1.84 (1.10 to 3.08)0.80 (0.46 to 1.35)0.80 (0.45 to 1.38)1.45 (0.84 to 2.46)
 Tricyclics†0.8 (0.4 to 1.6)0.33 (0.05 to 1.72)0.15 (0.02 to 0.79)0.55 (0.06 to 2.90)0.74 (0.12 to 3.49)1.55 (0.31 to 7.26)0.70 (0.07 to 3.69)
 Antipsychotics1.6 (1.0 to 2.6)1.46 (0.48 to 5.27)0.53 (0.18 to 1.51)3.08 (1.08 to 9.46)0.94 (0.31 to 2.69)0.74 (0.21 to 2.23)1.98 (0.67 to 5.64)
 Opiates‡4.8 (3.7 to 6.3)1.42 (0.73 to 2.89)0.91 (0.49 to 1.76)1.75 (0.94 to 3.24)1.06 (0.56 to 1.99)1.24 (0.65 to 2.31)1.73 (0.91 to 3.23)
 Anticonvulsants4.6 (3.5 to 6.0)1.46 (0.76 to 2.97)0.56 (0.30 to 1.04)1.83 (0.99 to 3.37)0.76 (0.39 to 1.42)1.69 (0.91 to 3.11)1.99 (1.07 to 3.68)
 Any medication19.9 (17.6 to 22.3)1.17 (0.84 to 1.62)0.67 (0.49 to 0.92)2.05 (1.49 to 2.80)1.01 (0.74 to 1.38)1.21 (0.88 to 1.67)2.50 (1.82 to 3.45)
  • This table lists the prevalence of detection of various substances in injured drivers and shows odds of testing positive in various driver groups. Statistically significant results (unadjusted for multiple comparisons) are bolded.

  • *These values represent the Norwegian per se limits for driving.

  • †Amphetamines include amphetamine, methamphetamine, MDMA and MDA.

  • ‡The percentages exclude drivers given morphine prior to blood drawn. Morphine is a metabolite of heroin. Codeine is also metabolised to morphine.

  • §Illicit drug other than cannabis.¶The percentages exclude drivers given dimenhydrinate prior to blood drawn (see text).

  • **These percentages exclude drivers who were given benzodiazepines by medical staff prior to blood draw.

  • Δ-9-THC, Δ-9-tetrahydrocannabinol; BAC, blood alcohol concentration; MDA, 3,4-methylenedioxyamphetamine; MDMA, 3,4-methylenedioxymethamphetamine; THC-COOH, tetrahydrocannabinol carboxylic acid.