TABLE 1—
Substance Use Prevalence Rates Among High School Students, by Sociodemographic and Psychosocial Characteristics: United States and South Africa, 2002–2003
| Past-Month Alcohol Use, % (95% CI) | Past-Month Heavy Alcohol Use, % (95% CI) | Past-Month Cigarette Use, % (95% CI) | Past-Month Marijuana Use, % (95% CI) | Lifetime Illicit Drug Use, % (95% CI) | ||||||
| United States | South Africa | United States | South Africa | United States | South Africa | United States | South Africa | United States | South Africa | |
| Gender | ||||||||||
| Male | 40.6 (37.6, 43.5)* | 43.4 (39.8, 47.0)** | 26.2 (23.7, 28.7) | 32.9 (29.8, 25.9)** | 20.0 (18.0, 20.9) | 30.4 (27.9, 33.0)** | 23.9 (21.0, 26.8)** | 14.3 (12.3, 16.3)** | 12.8 (10.6, 15.1) | 19.4 (16.6, 22.1) |
| Female | 43.2 (40.5, 45.8) | 27.5 (23.7, 31.3) | 25.6 (23.1, 28.0) | 18.2 (15.4, 20.9) | 21.4 (18.3, 24.6) | 15.7 (12.8, 18.5) | 18.6 (16.5, 20.8) | 5.1 (3.9, 6.3) | 11.5 (9.2, 13.7) | 17.2 (13.3, 21.0) |
| Race/ethnicity | ||||||||||
| Black | 35.8 (32.3, 39.3)** | 31.1 (28.2, 34.1)** | 14.1 (11.5, 16.8)** | 22.8 (20.3, 25.3)** | 14.6 (11.7, 17.6)** | 20.1 (17.8, 22.3)** | 22.7 (19.6, 25.7) | 9.1 (7.7, 10.6) | 5.9 (3.8, 7.9)** | 19.2 (16.1, 22.3)** |
| White | 43.2 (40.5, 47.1) | 68.8 (61.0, 76.6) | 29.2 (26.7, 31.7) | 41.9 (34.5, 49.3) | 23.7 (21.2, 26.2) | 41.5 (35.2, 47.9) | 20.8 (18.1, 23.4) | 7.6 (4.5, 10.8) | 12.4 (10.1, 14.7) | 7.6 (4.3, 10.9) |
| Age, y | ||||||||||
| ≤14 | 31.3 (27.2, 35.3)** | 22.3 (15.8, 28.7)** | 16.4 (13.3, 19.4)** | 14.2 (9.9, 18.5)** | 12.8 (9.6, 16.1)** | 15.0 (10.0, 19.9)* | 13.6 (11.2, 16.0)** | 3.7 (1.7, 5.8)** | 9.2 (6.8, 11.6)** | 13.5 (6.6, 20.4) |
| 15 | 40.3 (37.3, 43.2) | 29.3 (24.5, 34.0) | 23.1 (20.2, 26.0) | 20.8 (17.4, 24.1) | 19.1 (16.5, 21.7) | 19.4 (15.5, 23.2) | 20.7 (17.4, 24.1) | 4.7 (3.2, 6.2) | 11.7 (9.1, 14.2) | 14.8 (8.5, 21.0) |
| 16 | 44.7 (41.4, 48.1) | 35.1 (29.7, 40.4) | 27.8 (25.0, 30.7) | 23.2 (19.1, 27.3) | 22.1 (19.0, 25.2) | 22.5 (18.5, 26.4) | 22.2 (19.7, 24.8) | 8.7 (6.4, 10.9) | 12.4 (10.0, 14.8) | 13.4 (9.6, 17.1) |
| ≥ 17 | 48.1 (44.3, 52.0) | 34.0 (29.2, 38.8) | 35.2 (31.8, 38.5) | 24.9 (21.2, 28.6) | 27.5 (24.5, 30.5) | 21.5 (18.0, 25.0) | 27.1 (22.9, 31.2) | 10.6 (8.6, 12.6) | 15.1 (12.7, 17.5) | 22.3 (17.5, 27.1) |
| Grade | ||||||||||
| 9 | 36.2 (33.4, 39.0) | 31.3 (28.1, 34.5)** | 19.8 (17.4, 22.2)** | 24.0 (21.6, 26.5) | 17.4 (14.9, 19.8)** | 22.5 (20.0, 25.0) | 18.5 (15.5, 21.4)** | 8.6 (6.8, 10.5) | 11.1 (8.5, 13.7) | 22.5 (18.2, 26.8)** |
| 10 | 43.5 (40.3, 46.8) | 34.1 (27.3, 40.9) | 27.5 (24.5, 30.4) | 22.3 (17.2, 27.4) | 21.8 (18.9, 24.7) | 20.2 (15.2, 25.1) | 22.0 (19.1, 24.9) | 8.7 (6.2, 11.1) | 12.7 (10.2, 15.1) | 17.4 (12.7, 22.1) |
| 11 | 47.0 (43.0, 51.1) | 39.9 (34.7, 45.1) | 31.8 (28.8, 34.9) | 29.0 (24.6, 33.3) | 23.6 (20.4, 26.8) | 24.2 (20.0, 28.3) | 24.1 (21.1, 27.2) | 10.2 (8.0, 12.4) | 13.1 (10.6, 15.5) | 11.9 (8.1, 15.8) |
| Academic performance | ||||||||||
| Mostly As | 35.5 (32.3, 38.6)** | 30.8 (25.7, 35.8)* | 20.3 (17.9, 22.6)** | 19.1 (15.5, 22.8)** | 13.7 (11.9, 15.5)** | 18.1 (14.7, 21.5)** | 14.2 (12.1, 16.2)** | 7.6 (5.6, 9.7)** | 8.0 (6.2, 9.8)** | 21.9 (16.4, 27.4)* |
| Mostly Bs–Ds | 53.9 (50.1, 57.6) | 38.3 (34.0, 42.6) | 35.7 (31.7, 39.7) | 27.8 (24.4, 31.2) | 32.4 (27.9, 36.8) | 25.3 (21.8, 28.7) | 32.7 (29.2, 36.2) | 9.0 (7.4, 10.5) | 18.1 (15.2, 21.0) | 14.6 (11.8, 17.3) |
| Lower than | 63.9 (52.5, 75.3) | 38.7 (34.3, 43.1) | 47.7 (35.9, 59.4) | 30.7 (27.2, 34.3) | 44.5 (34.8, 54.1) | 26.4 (22.0, 30.8) | 49.8 (39.1, 60.4) | 12.8 (10.1, 15.6) | 33.0 (21.9, 44.0) | 18.0 (14.3, 21.7) |
| Overall | 41.8 (39.2, 44.4) | 34.3 (30.9, 37.7) | 25.9 (23.6, 28.1) | 24.4 (21.8, 27.1) | 20.7 (18.4, 23.0) | 22.0 (19.5, 24.4) | 21.3 (18.9, 23.7) | 9.0 (7.7, 10.3) | 12.2 (10.1, 14.2) | 18.1 (15.3, 20.9) |
Note. CI = confidence interval. In South Africa, “Black” comprised students self-identified as Black, “colored,” or Indian. In the United States, “Black” comprised students self-identified as Black or African American only.
* P < .05; **P < .01 (χ2 test)