Table 2.
Descriptive statistics related to illness absence and socio-demographic variables.
| Control schools | Intervention schools | |||
|---|---|---|---|---|
| N | % | N | % | |
| Grade levela | ||||
| Elementary school | 4528 | 47.3 | 5040 | 52.7 |
| Middle school | 3515 | 56.3 | 2731 | 43.7 |
| Gender | ||||
| Female | 3851 | 50.1 | 3837 | 49.9 |
| Male | 4192 | 51.6 | 3934 | 48.4 |
| Free or reduced luncha | 2092 | 59.7 | 1412 | 40.3 |
| Ethnic groupa | ||||
| Caucasian | 4957 | 47.2 | 5552 | 52.8 |
| Hispanic | 2170 | 63.5 | 1250 | 36.5 |
| Asian | 313 | 44.0 | 398 | 56.0 |
| Multi | 484 | 50.7 | 470 | 49.3 |
| Other | 119 | 54.1 | 101 | 45.9 |
| Ventilation assessment in the school | ||||
| Adequate in at least part of the classrooms | 9 | 42.9 | 12 | 57.1 |
| Inadequate in all classrooms | 8 | 61.5 | 5 | 38.5 |
aSignificant difference between intervention and control schools based on chi-square test (p < 0.05).