Table 1 Demographic characteristics of the SI and NSI groups
|  | SI (SD) | NSI (SD) | χ2(t) | p |
|---|---|---|---|---|
Gender (male%) | n = 21(43%) | n = 27(54%) | 1.230 | 0.267 |
Age (years) | 12.85 (0.61) | 12.87 (0.44) | − 0.164 | 0.870 |
Father’s education (years) | 10.21 (3.00) | 10.97 (2.19) | − 1.317 | 0.191 |
Mother’s education (years) | 9.82 (3.12) | 9.91 (2.51) | − 0.144 | 0.886 |