Table 1.
Demographic information (mean ± standard deviation).
| Measure | Female (F) | Male (M) | p-valuea | Group difference |
|---|---|---|---|---|
| Total subjects | 3895 | 4249 | - | - |
| Age (years) | 9.92 ± 0.62 | 9.95 ± 0.62 | 0.04 | F < M |
| Head sizeb (svol cm3) | 1341.5 ± 15.3 | 1342.0 ± 16.0 | NS | F=M |
| Socioeconomic Status (SES) | 18.0 ± 66.8 | 18.5 ± 67.8 | NS | F = M |
| Pubertal Development Scale (PDS) | 2.0 ± 1.0 | 1.3 ± 0.6 | ≤ 10−6 | F > M |
| Ethnicity (%)c: | ||||
| Asian/African American/Caucasian/Other | 269/631/2650/346 | 282/629/2975/363 | NS | F = M |
| Body Mass Index (BM1) z-scoresd | 0.23 ± 5.6 | 0.15 ± 14.1 | NS | F = M |
a
Measured by χ2-test or t-test: NS “=” not significantly different by p = 0.05; ‘ < ‘ or ‘ > ‘ significantly different at p ≤ 0.05.
b
Head size was measured after being affinely registered to the SRI24 template.
c
Individuals who self-identified as Hispanic were included in the Caucasian group: 493 girls and 574 boys.
d
z-Scores of the BMI (instead of percentile) are calculated by the pygrowup toolbox (pygrowup, 2017) for each individual to enable group comparison using t-test.