Table 1.
Summary characteristics of included studies
| Characteristic | Cannabis use (n = 22) |
|
| n | % | |
| Design | ||
| Repeated cross-sectional | 15 | 68.2 |
| Single cross-sectional | 7 | 31.8 |
| World regiona | ||
| North America | 7 | 31.8 |
| Europe | 8 | 36.4 |
| Oceania | 1 | 4.5 |
| >1 world region | 6 | 27.3 |
| Sample agea | ||
| Adolescent & young adult (11–26 years) | 8 | 36.4 |
| Adult (>18 years) | 3 | 13.6 |
| Adolescent and adult (>12 years) | 11 | 50.0 |
| Sample sizea | ||
| 1,000–9,999 | 4 | 18.2 |
| 10,000–19,999 | 2 | 9.1 |
| 20,000–49,999 | 2 | 9.1 |
| 50,000–99,999 | 7 | 31.8 |
| >100,000 | 6 | 27.3 |
| Time frameb | ||
| Past month | 1 | 4.5 |
| Past 12 months | 5 | 22.7 |
| Lifetime | 12 | 54.5 |
| Multiple | 4 | 18.2 |
a
Summary groupings are presented here. However, estimates included in meta-analysis coded country, sample age, and size specific to each estimate. Sample size and age were not reported by all studies.
b
For some studies, assessment time frame varied by survey year, country, or indicator measured. Estimates included in meta-analysis coded time frame specific to each estimate. Assessment time frame was not reported by all studies.