Table 1.
Characteristics of Samples and Balance Checking.
| Variables | (1) |
(2) |
(3) |
(4) |
|---|---|---|---|---|
| All samples (N = 832) | Control group (N = 404) | Treatment group (N = 428) | Differences (3)–(2) | |
| (1) Number of schools | 84 | 42 | 42 | —— |
| (2) Number of children who need eyeglasses | 832 | 404 | 428 | —— |
| Children’ characteristics | ||||
| (3) Gender (1 = male) | 0.496 (0.500) | 0.520 (0.500) | 0.474 (0.500) | −0.046 (0.036) |
| (4) Grade (1 = fifth grade) | 0.599 (0.490) | 0.601 (0.490) | 0.596 (0.491) | −0.006 (0.037) |
| (5) Vision acuity (LogMAR) | 0.467 (0.207) | 0.450 (0.204) | 0.483 (0.209) | 0.033* (0.018) |
| (6) Whether children have known that they need to wear eyeglasses (1 = yes) | 0.371 (0.483) | 0.372 (0.484) | 0.370 (0.483) | −0.002 (0.036) |
| Family characteristics | ||||
| (7) Both parents migrants (1 = yes) | 0.098 (0.298) | 0.105 (0.307) | 0.092 (0.289) | −0.013 (0.022) |
| (8) One of the parents have high school education (1 = yes) | 0.202 (0.402) | 0.183 (0.387) | 0.220 (0.414) | 0.036 (0.033) |
| (9) Family wealth (indicator) | 31767 (34650) | 30032 (33572) | 33376 (35586) | 3344 (5100) |
| School characteristics | ||||
| (10) Vision acuity examination in school (1 = yes) | 0.601 (0.490) | 0.609 (0.489) | 0.593 (0.492) | −0.015 (0.124) |
| (11) Vision protection course (1 = yes) | 0.762 (0.426) | 0.725 (0.447) | 0.797 (0.403) | 0.071 (0.088) |
Note. Data are from the baseline survey.
Standard Deviation adjusted at school level.
*
significant at 10% level.