Table 1.
Sociodemographic characteristics, digital technology use (combining weekday and weekend use), and BMI z score of the Study of Cognition, Adolescents, and Mobile Phones cohort.
| Sociodemographic characteristics | Overall (N=6616) | Bio-zone participants with measured height and weight (n=1473) | |||
| Age (years), median (IQR) | 12.06 (11.79-12.33) | 12.18 (11.94-12.44) | |||
| Sex, n (%) | |||||
|
|
Male | 3147 (47.57) | 747 (50.71) | ||
|
|
Female | 3469 (52.43) | 726 (49.29) | ||
| Ethnicity, n (%) | |||||
|
|
White | 2820 (42.62) | 643 (43.65) | ||
|
|
Black | 1016 (15.36) | 189 (12.83) | ||
|
|
Asian | 1758 (26.57) | 425 (28.85) | ||
|
|
Mixed | 740 (11.19) | 160 (10.86) | ||
|
|
Other | 62 (0.94) | 17 (1.15) | ||
|
|
Missing or not interpretable | 220 (3.33) | 39 (2.65) | ||
| Parental higher education, n (%) | |||||
|
|
At least one | 3677 (55.58) | 891 (60.49) | ||
|
|
None | 1200 (18.14) | 265 (17.99) | ||
|
|
Missing | 1739 (26.28) | 317 (21.52) | ||
| Parental occupation, n (%) | |||||
|
|
Managerial and professional | 3426 (51.78) | 867 (58.86) | ||
|
|
Intermediate | 1480 (22.37) | 300 (20.37) | ||
|
|
Routine and manual | 1040 (15.72) | 201 (13.65) | ||
|
|
Missing | 670 (10.13) | 105 (7.13) | ||
| School type, n (%) | |||||
|
|
State | 5141 (77.71) | 1035 (70.26) | ||
|
|
Independent | 1475 (22.29) | 438 (29.74) | ||
| Phone calls, n (%) | |||||
|
|
0-5 min | 2236 (33.8) | 559 (37.95) | ||
|
|
6-15 min | 1943 (29.37) | 405 (27.49) | ||
|
|
16-59 min | 867 (13.1) | 190 (12.9) | ||
|
|
>1 h | 444 (6.71) | 81 (5.49) | ||
|
|
Missing | 1126 (17.02) | 238 (16.16) | ||
| Internet use on mobile phones, n (%) | |||||
|
|
0-30 min | 2016 (30.47) | 459 (31.16) | ||
|
|
31-59 min | 858 (12.97) | 183 (12.42) | ||
|
|
1-2 h | 1094 (16.54) | 253 (17.18) | ||
|
|
>3 h | 1146 (17.32) | 264 (17.92) | ||
|
|
Missinga | 1502 (22.7) | 314 (21.32) | ||
| Video gaming on any device, n (%) | |||||
|
|
0-30 min | 3440 (51.99) | 788 (53.49) | ||
|
|
31-59 min | 981 (14.83) | 233 (15.82) | ||
|
|
1-2 h | 1252 (18.92) | 286 (19.42) | ||
|
|
>3 h | 733 (11.08) | 124 (8.42) | ||
|
|
Missing | 210 (3.17) | 42 (2.85) | ||
| BMI z score, mean (SD) | N/Ab | 0.43 (1.21) | |||
aParticipants who did not own a mobile phone were recorded as missing data.
bN/A: not applicable.