Table 1. Summary of Demographic Characteristics and Marijuana Use Among US Middle and High School Students, Monitoring the Future Survey, 2014 and 2015a .
| Characteristic | Weighted %b (Unweighted n = 12,988) | Marijuana Use, Weighted % | P Valuec | No. of Occasions of Marijuana Use in Past 30 Days Among Current Users, Weighted % |
||||||
|---|---|---|---|---|---|---|---|---|---|---|
| 1 or 2 | 3–5 | 6–9 | 10–19 | 20–39 | ≥40 | P Valuec | ||||
| Totald | — | 13.8 | — | 36.7 | 19.9 | 9.5 | 9.6 | 10.3 | 14.1 | — |
| Year | ||||||||||
| 2014 | 47.5 | 14.1 | .48 | 37.7 | 20.0 | 9.7 | 8.6 | 9.6 | 14.4 | .80 |
| 2015 | 52.5 | 13.6 | 35.7 | 19.8 | 9.3 | 10.6 | 10.8 | 13.7 | ||
| Grade | ||||||||||
| 8 | 32.9 | 6.2 | <.001 | 42.1 | 23.2 | 9.9 | 6.2 | 6.7 | 12.0 | .001 |
| 10 | 34.8 | 14.8 | 41.5 | 17.6 | 9.1 | 11.4 | 10.0 | 10.3 | ||
| 12 | 32.3 | 20.6 | 31.2 | 20.7 | 9.7 | 9.3 | 11.6 | 17.6 | ||
| Sex | ||||||||||
| Male | 48.4 | 14.2 | .11 | 30.4 | 17.9 | 11.2 | 11.0 | 12.8 | 16.7 | <.001 |
| Female | 51.6 | 13.0 | 43.9 | 22.6 | 7.9 | 8.3 | 8.3 | 9.1 | ||
| Race/ethnicity | ||||||||||
| Black | 15.2 | 14.9 | .04 | 37.0 | 19.4 | 10.0 | 8.5 | 11.7 | 13.4 | .31 |
| White | 63.6 | 12.6 | 37.6 | 18.9 | 9.6 | 8.7 | 10.8 | 14.5 | ||
| Hispanic | 21.2 | 14.6 | 37.2 | 25.7 | 9.2 | 11.7 | 7.3 | 8.9 | ||
| Parental education | ||||||||||
| <High school diploma | 8.3 | 16.2 | <.001 | 29.1 | 21.8 | 10.4 | 14.9 | 7.8 | 15.9 | .23 |
| High school diploma | 33.8 | 16.1 | 34.7 | 20.2 | 10.2 | 10.1 | 11.3 | 13.4 | ||
| College or higher | 57.9 | 11.6 | 41.2 | 19.5 | 9.2 | 9.0 | 9.8 | 11.4 | ||
| Regione | ||||||||||
| Northeast | 17.7 | 16.3 | <.001 | 40.7 | 15.5 | 8.9 | 11.2 | 10.6 | 13.0 | .17 |
| North Central | 22.1 | 12.5 | 36.0 | 18.0 | 11.8 | 8.7 | 10.1 | 15.4 | ||
| South | 37.8 | 12.7 | 35.0 | 19.0 | 9.1 | 9.5 | 12.0 | 15.4 | ||
| West | 22.5 | 14.9 | 36.1 | 26.5 | 8.6 | 9.2 | 7.6 | 12.0 | ||
| Population density | ||||||||||
| Large MSA | 31.3 | 15.0 | .004 | 39.2 | 19.5 | 9.0 | 10.0 | 10.2 | 12.0 | .65 |
| Other MSA | 48.4 | 14.0 | 35.9 | 19.3 | 10.0 | 10.0 | 10.6 | 14.1 | ||
| Non MSA | 20.3 | 11.6 | 33.8 | 22.3 | 8.9 | 7.6 | 9.3 | 18.0 | ||
Abbreviation: MSA, metropolitan statistical area.
National weights were applied to each student record to account for the complex survey design and adjust for nonresponse.
Rao–Scott χ2 test was used to determine P values for the weighted percentages.
Number of observations missing from each variable: grade (n = 0), sex (n = 594), race/ethnicity (n = 2,582), parental education (n = 1,194), region (n = 0), and population density (n = 0).
Northeast: Connecticut, Massachusetts, Maine, New Hampshire, New Jersey, New York, Rhode Island, Pennsylvania, and Vermont. North Central: Iowa, Kansas, Illinois, Indiana, Michigan, Minnesota, Missouri, Nebraska, North Dakota, Ohio, South Dakota, and Wisconsin. South: Alabama, Arkansas, Washington, DC, Delaware, Florida, Georgia, Kentucky, Louisiana, Maryland, Mississippi, North Carolina, Oklahoma, South Carolina, Tennessee, Texas, Virginia, and West Virginia. West: Arkansas, Arizona, California, Colorado, Idaho, Hawaii, Montana, Nevada, New Mexico, Oregon, Utah, Washington, and Wyoming.