Table 2.
Primary and Secondary Performance Outcomes by Treatment Group
| Outcomes | CBD (n=21) | Placebo (n=19) | p-Value | ESa |
|---|---|---|---|---|
| Mean (SD) | Mean (SD) | |||
| Total collisionsb | 0.90 (1.09) | 0.68 (0.95) | 0.52 | 0.23 |
| Percentage time out of lanec | 4.41 (2.44) | 4.34 (2.09) | 0.95 | 0.03 |
| SDLP#1c | 4.37 (2.22) | 3.88 (2.49) | 0.90 | 0.20 |
| SDLP #2c | 1.07 (0.77) | 0.98 (0.44) | 0.63 | 0.20 |
| Percentage time speedingc | 5.83 (6.02) | 8.27 (9.58) | 0.27 | 0.25 |
| Turn signal performanced,e | 0.51 (0.13) | 0.54 (0.10) | 0.54 | 0.30 |
| Drive time (seconds)d | 1,309 (58) | 1,281 (78) | 0.20 | 0.36 |
| Mean brake reaction timec | 0.60 (0.11) | 0.58 (0.12) | 0.61 | 0.17 |
a
ESs were calculated by subtracting the mean of the placebo group from the mean of the CBD group and dividing this difference by the placebo group's SD (i.e., Cohen's d).
b
p-value obtained from negative binomial regression comparing CBD with placebo.
c
p-values obtained from Mann‒Whitney U test comparing CBD with placebo.
d
p-values obtained by Student's t tests comparing CBD with placebo.
e
Turn signal performance was the proportion of good turn signal usage out of total possible turn signal maneuvers. This value ranges from 0 to 1. Values closer to 1 indicate better performance.
#, number; CBD, cannabidiol; ES, effect size; SDLP, SD of lateral position.