Table 1.
Participants and Information Included in Add Health Waves I, III, and IV.
| Students | Parents | Information Used in Current Study | ||
|---|---|---|---|---|
|
| ||||
| Wave | Core Sample | Oversamples | ||
|
| ||||
| Wave I In-Home Interview 1994–95 | Random selection from stratum of US students in grades 7–12 (N = 12,105) | Purposeful selection for oversamples plus saturation samples of 16 schools (N = 8,640) | Parents of participating students (N = 17,670) | * Demographic variables * Health report * Items for measurement of perceived belonging * Grades * Report of symptoms |
| Total in-home interview sample of grade 7–12 students at Wave I (N = 20,745) | ||||
| Wave III In-Home Interview 2001–02 | All Wave I respondents (now aged 18–26 years) who could be located and re-interviewed (N = 15,197) | * Information about on-time high school completion | ||
| Wave IV In-Home Interview 2007–08 | All Wave I respondents (now aged 24–32 years) who could be located and re-interviewed (N = 15,701) | * Information related to diagnosis of chronic medical conditions in childhood * Student level weights |
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