TABLE 2—
Coding Scheme Used for the Piecewise Model Using Quadratic Terms: Study of Growth Trajectories of Sexual Risk Behavior in Adolescence and Young Adulthood, Flint, Mich, 1994–2003
| Adolescence | Young Adulthood | |||||||
| Coded Time Variables | Wave 1 | Wave 2 | Wave 3 | Wave 4 | Wave 5 | Wave 6 | Wave 7 | Wave 8 |
| a1t | 0 | 1 | 2 | 3 | 3 | 3 | 3 | 3 |
| a2t | 0 | 1 | 4 | 9 | 9 | 9 | 9 | 9 |
| a3t | 0 | 0 | 0 | 0 | 1 | 2 | 3 | 4 |
| a4t | 0 | 0 | 0 | 0 | 1 | 4 | 9 | 16 |
Note. Study participants were interviewed starting in 1994 every year for 4 years (corresponding to participants’ high school years), followed by a 1-year gap, and then every year for 4 additional years, for a total of 8 waves of data.