Characteristics of the study sample compared with those ALSPAC participants not included in the study*
| Study sample (n=6015) (SDs given for means) | Other ALSPAC participants (n≤7602) (SDs given for means) | p Value† | |
|---|---|---|---|
| Male (%) | 49 | 53 | ≤0.001 |
| Autism spectrum disorder (maternal and formal report) (%) | 0.93 | 0.96 | 0.861 |
| Mean 2D:4D (those with left and right 2D:4D, excluding two outliers) | 0.964 (0.029) | 0.963 (0.030) | 0.421 |
| Age at 2D:4D measurement, months | 140.9 (2.8) | 141.3 (3.2) | ≤0.001 |
| Manual occupational background (%) | 14.2 | 25.3 | ≤0.001 |
| Mother educated to degree level (%) | 16.3 | 9.5 | ≤0.001 |
*Excluding multiple births, those not alive at 1 year, and those not in the core ALSPAC sample.
†From χ2 test for categorical variables, and unpaired t test (two-tailed) for continuous variables.
2D:4D, second-to-fourth digit ratio; ALSPAC, Avon Longitudinal Study of Parents and Children; n, number of participants.