Demographic characteristics of the sample
| Total Group (n = 208) (100%) | Controls (n = 105) (50.5%) | Nonaerated Sinuses (n = 103) (49.5%) | P Value | |
|---|---|---|---|---|
| Age (mean) (SD) (yr) | 8.00 (1.00) | 8.17 (1.01) | 7.83 (0.97) | .02 |
| Sex (%) | .78 | |||
| Male | 51.9 | 50.5 | 53.4 | |
| Female | 48.1 | 49.5 | 46.6 | |
| Ethnicity (%)a | .37 | |||
| Dutch | 65.9 | 65.7 | 66.0 | |
| Other Western | 8.2 | 9.5 | 6.8 | |
| Non-Western | 22.1 | 19.0 | 25.2 | |
| Nonverbal IQ (mean) (SD)b | 102.81 (14.42) | 103.87 (15.72) | 101.78 (13.04) | .33 |
| Maternal education (%)c | .19 | |||
| Low | 4.8 | 1.9 | 7.8 | |
| Medium | 36.1 | 34.3 | 37.9 | |
| High | 46.2 | 50.4 | 41.7 | |
| Handedness (%)d | .45 | |||
| Right | 87.5 | 89.5 | 85.4 | |
| Left | 9.6 | 7.6 | 11.7 |
↵a Missing data on ethnicity (3.8%).
↵b Missing data on nonverbal IQ (13.0%).
↵c Low indicates primary school/lower vocational education; Medium, intermediate vocational education; High, higher vocational education/university. Missing data on maternal education (11.5%).
↵d Missing data on handedness (2.9%).