Table 1.
Descriptive Statistics by Age
| Age | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 |
|---|---|---|---|---|---|---|---|---|---|
| Observations (Range)* | n = 0 - 5 | n = 80 - 84 | n = 135 - 152 | n = 118 - 140 | n = 91 - 115 | n = 77 - 100 | n = 61 - 84 | n = 22 - 28 | n = 1 - 2 |
| MSFc (hours past midnight) | 3.49 (1.00) | 3.71 (1.27) | 3.63 (1.36) | 4.01 (1.29) | 4.68 (1.21) | 5.40 (1.35) | 4.98 (1.76) | 5.22 (1.61) | 3.05 (0.00) |
| CESD | 1.05 (0.65) | 0.79 (0.52) | 0.79 (0.55) | 0.82 (0.50) | 0.74 (0.51) | 1.37 (0.72) | 1.70 (0.54) | 1.66 (0.50) | 2.00 (0.07) |
| Risky Behavior | 1.15 (0.23) | 1.63 (0.63) | 1.69 (0.60) | 1.75 (0.68) | 1.65 (0.66) | 1.84 (0.69) | 1.88 (0.75) | 1.94 (0.79) | 2.32 (1.86) |
| Substance Use | 0.00 (0.00) | 0.59 (0.98) | 0.89 (1.11) | 1.03 (1.22) | 1.50 (1.34) | 1.88 (1.51) | 2.16 (1.60) | 2.43 (1.50) | 3.50 (1.73) |
| Sleep Duration (hours) | 8.73 (1.60) | 7.97 (0.80) | 7.67 (0.92) | 7.73 (1.14) | 7.70 (1.08) | 7.89 (1.20) | 7.42 (1.54) | 7.31 (1.55) | 6.79 (0.00) |
| Sleep Quality | 5.00 (4.90) | 4.95 (2.84) | 5.32 (3.04) | 4.75 (2.76) | 3.99 (2.73) | 4.69 (2.82) | 4.45 (2.75) | 3.71 (2.03) | 3.50 (3.53) |
| Sex (% Female) | 80% | 54% | 58% | 56% | 58% | 58% | 65% | 57% | 50% |
| Asian | 20% | 19% | 23% | 22% | 17% | 14% | 17% | 11% | 0% |
| Latino | 20% | 48% | 43% | 37% | 49% | 46% | 49% | 39% | 0% |
| European American | 40% | 30% | 30% | 32% | 29% | 35% | 31% | 36% | 50% |
| Other | 20% | 3% | 4% | 9% | 5% | 5% | 3% | 14% | 50% |
*
Note. Observations are indicative of the number of data points per variable by age. The accelerated longitudinal design and two-year data collection intervals resulted not all participants providing data for each year. Since this number varied depending on the variable of interest, a range of observations is listed above.