Table 1. Characteristics of participants.
| Characteristics | No. (%) | |
|---|---|---|
| Age, yr | ||
| 2 | 58 (15.3) | |
| 3 | 167 (43.9) | |
| 4 | 116 (30.5) | |
| 5 | 39 (10.3) | |
| Sex | ||
| Male | 198 (52.1) | |
| Female | 182 (47.9) | |
| Main caregiver | ||
| Parents | 358 (94.2) | |
| Grandparents | 19 (5.8) | |
| Paternal education | ||
| High school or below | 41 (10.8) | |
| College or above | 339 (89.2) | |
| Maternal education | ||
| High school or below | 41 (10.8) | |
| College or above | 337 (88.7) | |
| Paternal employment status | ||
| Unemployed | 5 (1.3) | |
| Employed | 375 (98.7) | |
| Maternal employment status | ||
| Unemployed | 244 (64.2) | |
| Employed | 136 (35.8) | |
| Monthly household income, KRW | ||
| < 4,000,000 | 190 (50.0) | |
| ≥ 4,000,000 | 190 (50.0) | |
| Ownership of media devices | ||
| Television | 360 (94.7) | |
| Smartphone | 364 (95.8) | |
| Tablet | 183 (48.2) | |
| Computer | 343 (90.3) | |
| Video game console | 56 (14.7) | |
| Handheld game console | 38 (10.0) | |
| Screen overuse (≥ 1 hr/day) | ||
| Television | 184 (48.4) | |
| Smartphone | 38 (10.0) | |
| Tablet | 24 (6.3) | |
| Computer | 15 (3.9) | |
| Video game console | 2 (0.5) | |
| Handheld game console | 0 (0.0) | |