TABLE 1.
General indicators of substance use patterns for the Woodlawn cohort
| Substance | Lifetime prevalence | Age of first use | Age of last usea |
|---|---|---|---|
| Percent (SE) | Mean age (SE) | Mean age (SE) | |
| Alcohol | 97.0% (0.5) | 16.5 (0.1) | – |
| Males | 96.2% (0.8) | 15.4 (0.2)* | – |
| Females | 97.8% (0.6) | 17.4 (0.1)* | – |
| Tobacco | 75.7% (1.3) | 16.5 (0.2) | 25.8 (0.6) |
| Males | 76.6% (1.9) | 16.4 (0.2) | 26.4 (1.0) |
| Females | 74.9% (1.8) | 16.6 (0.2) | 25.4 (0.8) |
| Marijuana | 58.3% (1.5) | 16.6 (0.1) | 26.5 (0.4) |
| Males | 64.5% (2.1)* | 16.2 (0.2)* | 27.5 (0.6)* |
| Females | 52.6% (2.1)* | 17.1 (0.2)* | 25.5 (0.6)* |
| Cocaine/Crack | 29.9% (1.4) | 23.6 (0.3) | 31.1 (0.5) |
| Males | 35.1% (2.1)* | 23.6 (0.4) | 31.6 (0.6) |
| Females | 25.1% (1.8)* | 23.6 (0.4) | 30.7 (0.7) |
| Heroin | 7.6% (0.8) | 25.3 (0.8) | 30.7 (0.9) |
| Males | 9.7% (1.3)* | 24.9 (1.0) | 30.8 (1.1) |
| Females | 5.6% (1.0)* | 25.8 (1.2) | 30.6 (1.4) |
aAge of last use is among those users who had not used in the past 12 months.
*Significant gender differences at p < .05 based on t-test comparisons.