Comparison of sociodemographic characteristics and physical activity between the non-increased group and the increased group
| Variables | Changes of screen time | P value | |
| Non-increased group (n=331) | Increased group (n=790) | ||
| Children | |||
| Males, n (%) | 160 (48.3%) | 406 (51.4%) | 0.351 |
| Age, years | 4.7±0.8 | 4.9±0.8 | 0.003 |
| Being a single child, n (%) | 193 (58.3%) | 454 (57.5%) | 0.795 |
| Parents | |||
| Paternal age, years | 36.5±5.1 | 36.7±5.0 | 0.499 |
| Maternal age, years | 34.1±4.3 | 34.4±4.2 | 0.322 |
| Father’s education level, n (%) | |||
| Junior high school and below | 26 (7.9%) | 44 (5.6%) | 0.149 |
| High school | 52 (15.7%) | 122 (15.4%) | 0.910 |
| College or university degree | 238 (71.9%) | 575 (72.8%) | 0.763 |
| Master’s degree and above | 15 (4.5%) | 49 (6.2%) | 0.271 |
| Mother’s education level, n (%) | |||
| Junior high school and below | 18 (5.4%) | 45 (5.7%) | 0.864 |
| High school | 54 (16.3%) | 127 (16.1%) | 0.921 |
| College or university degree | 227 (68.6%) | 529 (66.9%) | 0.598 |
| Master’s degree and above | 32 (9.7%) | 89 (11.3%) | 0.432 |
| Marital status, n (%) | |||
| Married | 317 (95.8%) | 759 (96.1%) | 0.812 |
| Divorced | 13 (3.9%) | 28 (3.5%) | 0.755 |
| Single | 1 (0.3%) | 3 (0.4%) | 1.000 |
| Maternal work status, n (%) | |||
| Regular work | 258 (77.9) | 606 (76.7%) | 0.653 |
| Remote work | 36 (10.9%) | 103 (13.0%) | 0.316 |
| Out of work | 37 (11.2%) | 81 (10.3%) | 0.645 |
| Parenting, n (%) | |||
| Caregivers | |||
| Mother | 197 (59.5%) | 461 (58.4%) | 0.718 |
| Father | 16 (4.8%) | 50 (6.3%) | 0.332 |
| Ancestor | 114 (34.4%) | 274 (34.7%) | 0.938 |
| Nursemaid | 3 (0.9%) | 2 (0.3%) | 0.156 |
| Others | 1 (0.3%) | 3 (0.4%) | 1.000 |
| Reduced maternal parenting time | 16 (4.8%) | 47 (5.9%) | 0.459 |
| Reduced paternal parenting time | 16 (4.8%) | 51 (6.5%) | 0.335 |
| Socioeconomic characteristics | |||
| Living environment | |||
| Urban, n (%) | 321 (97.0%) | 772 (97.7%) | 0.467 |
| Suburban county, n (%) | 5 (1.5%) | 9 (1.1%) | 0.610 |
| Towns, n (%) | 3 (0.9%) | 7 (0.9%) | 1.000 |
| Rural area, n (%) | 2 (0.6%) | 2 (0.3%) | 0.586 |
| Living space class, n (%) | |||
| ＜80 m2 | 22 (6.6%) | 57 (7.2%) | 0.647 |
| 80–100 m2 | 144 (43.5%) | 334 (42.3%) | 0.705 |
| 100–150 m2 | 145 (43.8%) | 335 (42.4%) | 0.665 |
| 150–200 m2 | 14 (4.2%) | 48 (6.1%) | 0.217 |
| ≥200 m2 | 6 (1.8%) | 16 (2.0%) | 0.815 |
| Annual household income, n (%) | |||
| ＜¥80 000 | 75 (22.7%) | 97 (12.3%) | 0.009 |
| ¥80 000–¥150 000 | 79 (23.9%) | 199 (25.2%) | 0.640 |
| ≥¥150 000 | 177 (53.4%) | 494 (62.5%) | 0.005 |
| Physical activities, hour/day | |||
| Decrease of time spent outdoors | 1.0 (2.0) | 1.5 (1.0) | <0.001 |
| Decrease of MVPA | 0.0 (1.0) | 1.0 (1.0) | <0.001 |
MVPA, moderate-vigorous physical activity.