Characteristics | Case group (n = 424) | Control group (n = 1272) | Statistics |
---|---|---|---|
Age (year) M (SD) | 10.93 (1.76) | 11.07 (2.02) | t = 1.353 |
Gender (%) |  |  | χ2 = 2.216 |
 Boy | 213 (50.2%) | 586 (46.1%) |  |
 Girl | 211 (49.8%) | 686 (53.9%) |  |
Left behind children (%) | 220 (51.9%) | 453 (35.6%) | χ2 = 35.185** |
Primary caregiver (%) |  |  | F = 35.255** |
 Mother | 157 (37.0%) | 908 (71.4%) |  |
 Father | 21 (5.0%) | 115 (9.0%) |  |
 Grandparents | 235 (55.4%) | 235 (18.5%) |  |
 Baby sister or others | 11 (2.6%) | 14 (1.1%) |  |
Primary caregiver’s education |  |  | F = 6.008* |
 Illiteracy | 27 (6.4%) | 39 (3.1%) |  |
 Elementary school | 100 (23.6%) | 278 (21.9%) |  |
 Junior high school | 233 (54.9%) | 754 (59.3%) |  |
 Senior high school | 57 (13.4%) | 152 (11.9%) |  |
 Above college | 7 (1.7%) | 49 (3.9%) |  |
Health of primary caregiver | 8.68 (2.47) | 9.14 (3.99) | t = 2.232* |
Mother’s age | 36.56 (6.00) | 37.51 (6.00) | t = 2.977* |
Mother’s education |  |  | F = 0.050 |
 Illiteracy | 21 (5.0%) | 56 (4.4%) |  |
 Elementary school | 81 (19.1%) | 291 (22.9%) |  |
 Junior high school | 255 (60.1%) | 711 (55.9%) |  |
 Senior high school | 53 (12.5%) | 164 (12.9%) |  |
 Above college | 14 (3.3%) | 50 (3.9%) |  |
Father’s age | 38.19 (6.07) | 39.18 (5.60) | t = 2.944* |
Father’s education |  |  | F = 110.423** |
 Illiteracy | 5 (1.2%) | 3 (0.2%) |  |
 Elementary school | 87 (20.5%) | 30 (2.3%) |  |
 Junior high school | 275 (64.9%) | 953 (74.9%) |  |
 Senior high school | 46 (10.8%) | 220 (17.3%) |  |
 Above college | 11 (2.6%) | 66 (5.2%) |  |
Household income (per person per month in yuan) |  |  | F = 7.892** |
  < 1000 RMB | 50 (11.8%) | 83 (6.5%) |  |
 1000–3000 RMB | 241 (56.8%) | 442 (34.7%) |  |
 3001–5000 RMB | 97 (22.9%) | 569 (44.7%) |  |
  > 5000 RMB | 33 (7.8%) | 178 (14.0%) |  |