Table 3.
Sample characteristics based on age of onset of nonmedical use of prescription stimulants (total across the 4 waves of the SSLS; n = 4755)
| Age of Onset of Nonmedical Use of Prescription Stimulants | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Contrast 1 | Contrast 2 | Contrast 3 | |||||||
| Never Used (n = 4631) % |
Early Onset (n = 46) % |
p(a) | Never Used (n = 4631) % |
Late Onset (n = 78) % |
p(a) | Early Onset (n = 46) % |
Late Onset (n = 78) % |
p(a) | |
| Gender | |||||||||
| Male | 49.1% | 45.7% | 49.1% | 37.2% | * | 45.7% | 37.2% | ||
| Female | 50.9% | 54.3% | 50.9% | 62.8% | 54.3% | 62.8% | |||
| Race | |||||||||
| White | 61.8% | 78.3% | * | 61.8% | 89.7% | *** | 78.3% | 89.7% | |
| Black | 32.5% | 15.2% | 32.5% | 3.8% | 15.2% | 3.8% | |||
| Other Race | 5.7% | 6.5% | 5.7% | 6.4% | 6.5% | 6.4% | |||
| Grade level | |||||||||
| 7th or 8th grade | 35.2% | 26.1% | 35.2% | 5.1% | *** | 26.1% | 5.1% | *** | |
| 9th or 10th grade | 31.8% | 45.7% | 31.8% | 38.5% | 45.7% | 38.5% | |||
| 11th or 12th grade | 33.0% | 28.3% | 33.0% | 56.4% | 28.3% | 56.4% | |||
| Parental education | |||||||||
| Parents have less than a college degree | 25.1% | 28.3% | 25.1% | 16.7% | 28.3% | 16.7% | |||
| At least one parent has a college degree or higher | 74.9% | 71.7% | 74.9% | 83.3% | 71.7% | 83.3% | |||
| YSR conduct disorder severity | |||||||||
| Conduct disorder severity (normal) | 89.6% | 30.4% | *** | 89.6% | 56.4% | *** | 30.4% | 56.4% | * |
| Conduct disorder severity (borderline) | 4.9% | 17.4% | 4.9% | 12.8% | 17.4% | 12.8% | |||
| Conduct disorder severity (clinically significant) | 5.5% | 52.2% | 5.5% | 30.8% | 52.2% | 30.8% | |||
| ADHD diagnosis | |||||||||
| Never diagnosed with ADHD | 88.7% | 54.3% | *** | 88.7% | 83.3% | 54.3% | 83.3% | *** | |
| Diagnosed with ADHD | 11.3% | 45.7% | 11.3% | 16.7% | 45.7% | 16.7% | |||
| YSR ADHD severity | |||||||||
| ADHD severity (normal) | 90.3% | 52.2% | *** | 90.3% | 71.8% | *** | 52.2% | 71.8% | |
| ADHD severity (borderline) | 6.5% | 28.3% | 6.5% | 17.9% | 28.3% | 17.9% | |||
| ADHD severity (clinically significant) | 3.2% | 19.6% | 3.2% | 10.3% | 19.6% | 10.3% | |||
| Past-year medical use of prescription stimulants | |||||||||
| Did not medically use prescription stimulants | 95.3% | 65.2% | *** | 95.3% | 91.0% | 65.2% | 91.0% | *** | |
| Medically used prescription stimulants | 4.7% | 34.8% | 4.7% | 9.0% | 34.8% | 9.0% | |||
| Past-year nonmedical use of prescription stimulants | |||||||||
| Did not nonmedically use prescription stimulants | 100.0% | 39.1% | *** | 100.0% | 17.9% | *** | 39.1% | 17.9% | ** |
| Nonmedically used prescribed stimulants | 0.0% | 60.9% | 0.0% | 82.1% | 60.9% | 82.1% | |||
| Onset of medical use of prescription stimulants | |||||||||
| Never used prescribed stimulants medically | 93.8% | 54.3% | *** | 93.8% | 80.8% | *** | 54.3% | 80.8% | *** |
| Early onset of medical use | 2.9% | 23.9% | 2.9% | 3.8% | 23.9% | 3.8% | |||
| Late onset of medical use | 3.2% | 21.7% | 3.2% | 15.4% | 21.7% | 15.4% | |||
| Past-year cigarette smoking | 10.0% | 67.4% | *** | 10.0% | 76.9% | *** | 67.4% | 76.9% | |
| Past-year binge drinking | 9.1% | 60.9% | *** | 9.1% | 78.2% | *** | 60.9% | 78.2% | * |
| Past-year marijuana use | 17.4% | 78.3% | *** | 17.4% | 91.0% | *** | 78.3% | 91.0% | * |
| Past-year cocaine use | 0.5% | 41.3% | *** | 0.5% | 12.8% | *** | 41.3% | 12.8% | ** |
| Past-year other illicit drug use | 2.7% | 67.4% | *** | 2.7% | 48.7% | *** | 67.4% | 48.7% | * |
| Past-year other nonmedical prescription drug use | 9.8% | 76.1% | *** | 9.8% | 52.6% | *** | 76.1% | 52.6% | ** |
| Positive DAST-10 screen | 11.0% | 78.3% | *** | 11.0% | 82.1% | *** | 78.3% | 82.1% | |
| Positive CRAFFT screen | 17.0% | 80.4% | *** | 17.0% | 93.6% | *** | 80.4% | 93.6% | * |
*
p<.05,
**
p<.01,
***
p<.001
(a)
Significance tests were based on Chi-square tests of independence (2×2 and 2×3). Results for 2×2 analyses were truncated, refer to table 1 for truncated groups