Table 1.
Descriptive Characteristics and Frequencies of 45 Studies Included
| Characteristic | K | N | M (SD) |
|---|---|---|---|
| Sample size | 44 | 320,872 | 7,292.55 (16,567.61) |
| Age (range) | 36 | 303,435 | 12.52 (2.10)–17.32 (2.79) |
| Age (mean) | 27 | 135,517 | 15.32 (1.62) |
| Sex (% female) | 42 | 318,906 | 52.97 (9.10) |
| Objective SES | |||
| Parental education—Low | 16 | 164,982 | 18.90% (15.14) |
| Parental education—High | 18 | 171,428 | 25.15% (13.56) |
| Unemployment | 8 | 20,907 | 13.56% (9.89) |
| Subjective SES | |||
| Society ladder | 12 | 31,467 | 6.51 (0.76) |
| School ladder | 9 | 28,853 | 6.80 (1.12) |
| Likert scale—Low | 22 | 277,135 | 11.41% (9.87) |
| Likert scale—High | 17 | 257,939 | 15.15% (11.80) |
| Financial constraints | 6 | 11,448 | |
| Region | |||
| North America | 19 | 48,739 | |
| Western Europe | 6 | 34,794 | |
| Eastern Europe | 12 | 26,324 | |
| Asia | 5 | 208,590 | |
| Australia | 1 | 97 | |
| Study Quality | 44 | 320,872 | 4.46 (1.38) |
| Population-representative | 10 | 74,698 | |
| N > 1,000 | 33 | 306,405 | |
| Participation rate > 80% | 25 | 265,473 | |
| Control for potential confounders | 37 | 303,204 | |
| Control for objective SES | 29 | 209,604 | |
| Objective SES = two measures, parent-reported | 6 | 19,352 | |
| Validated measures for > 50% outcomes | 19 | 34,739 | |
| Appropriate statistics, presented adequately | 39 | 308,893 | |
Note. K = number of studies reporting this information; N = total number of participants; M = Mean; SD = standard deviation.