Table 1.
Descriptive statistics in the first wave in both cohorts
| Add Health (n = 10,106) |
NELS:88 (n = 15,214) |
|
|---|---|---|
| Mean/ Proportion |
Proportion | |
| Age (years) | 15.07 | - |
| Age (groups) | ||
| ≤13 years | - | 1% |
| 14 years | - | 63% |
| 15 years | - | 31% |
| ≥16 years | - | 5% |
| Gender | ||
| Male | 50% | 50% |
| Female | 50% | 50% |
| Race/ethnicity | ||
| White | 72% | 73% |
| Black | 16% | 13% |
| Asian/Pacific Islander | 4% | 3% |
| Other | 8% | 11% |
| First language | ||
| English | 93% | 91% |
| Other | 7% | 9% |
| Urbanicity | ||
| Urban | 33% | 25% |
| Suburban | 28% | 44% |
| Rural | 29% | 31% |
| Parental education | ||
| Less than high school | 11% | 10% |
| High school | 32% | 20% |
| Some college | 21% | 42% |
| College graduate | 35% | 28% |
| Parental marital status | ||
| Married | 73% | 80% |
| Unmarried | 27% | 20% |
| Household income (quartiles) | ||
| 1 | 24% | 27% |
| 2 | 26% | 29% |
| 3 | 29% | 21% |
| 4 | 21% | 23% |
Results weighted. In Add Health, some participants were missing data on parental education (n = 504; 5%), parental marital status (n = 697; 7%), and household income (n = 1819, 18%). In NELS:88, some participants were missing data on parental education (n = 6; 0.004%), parental marital status (n = 371; 2%), and household income (n = 641; 4%). Household income quartiles differed slightly across cohorts (Add Health $0-$20,000, $21,000-$38,000, $39,000-$60,000, $61,000+; NELS:88 $0–$19,999, $20,000–$34,999, $35,000–$49,999, $50,000+)