Table 2.
Basic characteristics.
| Characteristic | Total sample (n=1124) |
Prompt (n=586) |
No prompt (n=538) |
t | X2 | df | P |
| Age in years, mean (SD) | 10.35 (0.57) | 10.32 (0.56) | 10.38 (0.57) | 1.62 | - | 1098 | .11 |
| Gender, n (%) girl | 623 (55.43) | 336 (57.34) | 287 (53.35) | - | 1.81 | 1 | .18 |
| Ethnicity, n (%) Western | 961 (85.50) | 500 (85.32) | 461 (85.69) | - | 0.03 | 1 | .86 |
| SESa, n (%) high SES | 484 (43.06) | 245 (41.81) | 239 (44.42) | - | 0.13 | 1 | .72 |
| Email address, n (%) yes | 1120 (99.64) | 585 (99.83) | 535 (99.44) | - | 1.18 | 1 | .28 |
| Email address use, n (%) yes | 1107 (98.49) | 577 (98.46) | 530 (98.51) | - | 0.46 | 1 | .50 |
| Mobile phone, n (%) yes | 175 (15.57) | 84 (14.33) | 91 (16.91) | - | 0.14 | 1 | .71 |
| Mobile phone use, n (%) yes) | 169 (15.04) | 83 (14.16) | 86 (15.99) | - | 2.44 | 1 | .12 |
aSES: socioeconomic status