Table 1.
Characteristics of Included Studies
| Studies (N) or participants (n) | Citations | |
|---|---|---|
| Study design | ||
| Randomized, DB, PC | N=11 | 23,25,26,28,29,31,34–37,39 |
| Nonrandomized,a DB, PC | N=5 | 22,27,30,32,38 |
| Nonrandomized, SB,b PC | N=3 | 24,33,40 |
| Pre-/post-trial | N=1 | 41 |
| Participant characteristics | ||
| Male | n=297 | — |
| Female | n=79 | — |
| Sex not specified | n=82 (N=4) | 31,32,40,41 |
| Average age ≤30 years | N=15 | 22–24,26,28–31,34–39,41 |
| Average age >30 years | N=4 | 25,31,32,40 |
| Average age not specified | N=2 | 27,33 |
| “Regular” cannabis usersc | N=4 | 22,28,29,37 |
| “Other” cannabis usersc | N=16 | 23–27,30–36,38–41 |
| Healthy population | N=20 | 22–41 |
| Treatment characteristics | ||
| Smoked cannabis or THC | N=13 | 22–24,28–31,33,35,37,38,40,41 |
| Ingested cannabis or THC | N=7 | 25–27,32,34,36,39 |
| THC dose unknown | N=5 | 22–24,30,35 |
| THC dose (mg) (median [IQR]) | 16 [11–26]d | — |
| Type of performance teste | ||
| Divided attention | N=6 | 22,25–27,30,33 |
| Executive function | N=4 | 23,30,34,35 |
| Information processing | N=11 | 22–28,30,33,34,36 |
| Tracking performance | N=1 | 33 |
| Reaction time | N=5 | 22,23,27,34,35 |
| Motor function | N=3 | 28,30,35 |
| Sustained attention | N=4 | 27,28,34,37 |
| Working memory | N=6 | 22,23,30,34–36 |
| Perception | N=3 | 22,24,30 |
| Learning and(or) memory | N=9 | 22–25,27,28,30,34,35 |
| Spatial reasoning | N=1 | 35 |
| Driving performance | N=4 | 29,37–39 |
| Flying performance | N=3 | 31,40,41 |
| Unknown | N=2 | 32,36 |
| Time of performance test | ||
| >8 to 12 h Post-treatment | N=7 | 22,24–27,33,37 |
| >12 to 24 h Post-treatment | N=16 | 23,25,28–41 |
| >24 to 48 h Post-treatment | N=8 | 23,26,28,29,31,34,35,40 |
| ≤8 h Post-treatment | N=18 | 23–26,28–41 |
| “Recovery” conditions | ||
| Supervised | N=8 | 22–24,27,30,35,36,39 |
| Unsupervised | N=10 | 26,28,29,31–34,38,40,41 |
| Unclear or not specified | N=2 | 25,37 |
a
Includes studies that did not indicate whether randomization was performed.
b
Includes studies that did not indicate whether researchers were blinded.
c
As defined in “Data synthesis” section.
d
Across all trials where the THC dose is known.
e
Includes those administered >8 h post-treatment, only.
DB, double blind; IQR, interquartile range; PC, placebo controlled; SB, single blind; THC, Δ9-tetrahydrocannabinol.