Table 1.
Characteristics of the study participants.
| Variables | Cases (N = 120) | Control (N = 145) | p Value |
|---|---|---|---|
| Age Mean (SD) | 7.73 (1.09) | 6.96 (0.53) | 1.000 |
| Race | |||
| Han | 117 (97.50) | 129 (98.47) | 0.459 * |
| Others | 3 (2.50) | 2 (1.53) | |
| Missing | 0 | 14 | |
| Residential area | 0.002 | ||
| City | 89 (74.79) | 117 (90.70) | |
| Township | 21 (17.65) | 6 (4.65) | |
| Countryside | 9 (7.56) | 6 (4.65) | |
| Missing | 1 | 16 | |
| Guardian education | 0.007 * | ||
| Elementary school or below | 2 (1.75) | 0 (0.00) | |
| Junior high school | 31 (27.19) | 18 (14.52) | |
| High school/technical school | 26 (22.81) | 21 (16.94) | |
| College/vocational college | 21 (18.42) | 42 (33.87) | |
| University | 34 (29.82) | 43 (34.68) | |
| Missing | 6 | 21 | |
| Para | 0.001 | ||
| 1 child | 102 (89.47) | 86 (72.27) | |
| ≥2 children | 12 (10.53) | 33 (27.73) | |
| Missing | 6 | 26 | |
| Delivery method | 0.877 | ||
| Natural birth | 62 (51.67) | 72 (50.70) | |
| Cesarean section | 58 (48.33) | 70 (49.30) | |
| Missing | 0 | 3 | |
| Preterm birth | 0.212 | ||
| Yes | 10 (8.40) | 6 (4.55) | |
| No | 109 (91.63) | 126 (95.45) | |
| Missing | 1 | 13 | |
| Child BMI (kg/m2) | 17.84 (10.39) | 16.50 (3.64) | 0.917 |
| Mother BMI (kg/m2) | 22.63 (3.90) | 24.03 (8.02) | 0.041 |
| Father BMI (kg/m2) | 25.90 (8.74) | 26.63 (7.32) | 0.235 |
| Missing | 1 | ||
| Mother’s early history of puberty | |||
| Yes | 2 (1.67) | 1 (1.08) | 1.000 * |
| No | 118 (98.33) | 92 (98.92) | |
| Missing | 0 | 52 | |
| Father’s early history of puberty | 0.105 * | ||
| Yes | 3 (2.50) | 0 (0.00) | |
| No | 117 (97.50) | 133 (100.00) | |
| Missing | 0 | 12 | |
| Feeding method after birth | 0.440 | ||
| Breastfeeding | 55 (46.61) | 59 (41.55) | |
| Formula | 19 (16.10) | 19 (13.38) | |
| Mixed feeding | 44 (37.29) | 64 (45.07) | |
| Missing | 2 | 3 | |
| Fried food | 0.670 | ||
| Yes | 84 (71.19) | 81 (68.64) | |
| No | 34 (28.81) | 37 (31.36) | |
| Missing | 2 | 27 | |
| Desserts | 0.441 | ||
| Yes | 107 (92.24) | 118 (89.39) | |
| No | 9 (7.76) | 14 (10.61) | |
| Missing | 4 | 13 | |
| Soft drinks | 0.244 | ||
| Yes | 60 (50.85) | 47 (43.12) | |
| No | 58 (49.15) | 62 (56.88) | |
| Missing | 2 | 36 | |
| Child sleeping hours (24 h) | 8.89 (1.46) | 9.15 (0.67) | 0.028 |
| Missing | 4 | 2 | |
| Child Snore | 0.611 * | ||
| Never | 37 (31.62) | 56 (39.44) | |
| Only on cold or allergy | 32 (27.35) | 33 (23.24) | |
| Sometimes | 45 (38.46) | 49 (34.51) | |
| Always | 3 (2.56) | 4 (2.82) | |
| Missing | 3 | 3 | |
| Time on screening devices per day | 0.716 * | ||
| Never | 17 (14.66) | 27 (18.88) | |
| <30 min | 49 (42.24) | 65 (45.45) | |
| 30–60 min | 26 (22.41) | 28 (19.58) | |
| 1–2 h | 22 (18.97) | 20 (13.99) | |
| >2 h | 2 (1.72) | 3 (2.10) | |
| Missing | 4 | 2 | |
| Time spent in outdoor activities | 0.011 * | ||
| None | 1 (0.85) | 1 (0.70) | |
| Rarely | 24 (20.51) | 20 (14.08) | |
| Often but less than 1 h | 58 (49.57) | 51 (35.92) | |
| 1–3 h | 28 (23.93) | 62 (43.66) | |
| More than 3 h | 6 (5.13) | 8 (5.63) | |
| Missing | 3 | 3 | |
| The intensity of outdoor activities | 0.484 | ||
| High | 32 (27.59) | 31 (21.83) | |
| Moderate | 67 (57.76) | 92 (64.79) | |
| Low | 17 (14.66) | 19 (13.38) | |
| Missing | 4 | 3 | |
| Secondhand smoke exposure | 0.766 | ||
| None | 63 (53.85) | 69 (47.92) | |
| Several times a month but less than once a week | 20 (17.09) | 31 (21.53) | |
| Several times a week but less than once a day | 17 (14.53) | 22 (15.28) | |
| Almost everyday | 17 (14.53) | 22 (15.28) | |
| Missing | 3 | 1 |
Abbreviations: SD, standard deviation; BMI, body mass index. Chi-square (ꭓ2)/Fisher’s test and t-test were between the cases and controls. * Indicate Fisher’s test. p value < 0.05.