Table. Characteristics of Participants in the Study Sample and Group Comparisons for the Continuous Measures.
| Characteristic | Mean (SD) | Levene test | Group difference | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Total sample | Lost to follow-up | No FH | FH-TD | FH-Other | FH-Aut | P value | η 2 a | ||
| Total, No. | 104 | 3 | 22 | 45 | 20 | 14 | NA | NA | NA |
| Female, No. | 53 | 2 | 11 | 28 | 11 | 1 | NA | NA | NA |
| Age, mo | 8.3 (1.2) | 8.7 (0.6) | 8.2 (1.1) | 8.2 (1.2) | 8.5 (1.2) | 8.1 (1.2) | >.99 | .78 | 0.01 |
| F-N N290 latency | 6.68 (19.46) | −10.23 (5.89) | 17.16 (20.53)b | 4.83 (17.79) | 7.42 (17.81) | −1.32 (21.12)b | .89 | .03 | 0.09 |
| Autism PGS (threshold P = .01) | 0.11 (0.98) | 0.62 (0.77) | 0.31 (1.02) | −0.15 (0.94)b | −0.07 (0.73)c | 0.82 (1.02)b,c | .49 | .006 | 0.12 |
| Cross disorder PGS (threshold P = .50) | 0.09 (1.03) | 0.32 (0.48) | −0.20 (1.20) | 0.13 (1.04) | 0.14 (0.83) | 0.27 (1.07) | .59 | .54 | 0.02 |
| Mullen Scales of Early Learning Composite standard score at 8 mo | 104.29 (15.74) | 92.67 (15.50) | 111.32 (13.47)b | 105.22 (15.96) | 101.60 (15.08) | 96.57 (15.64)b | .89 | .03 | 0.09 |
| Mullen Scales of Early Learning Composite standard score at 3 y | 107.94 (21.15) | NA | 121.40 (13.11)d,e | 112.18 (14.51)f | 98.60 (24.77)d | 88.71 (24.91)e,f | .009 | <.001 | η2[H] = 0.19g |
Abbreviations: FH-Aut, infants with a family history of autism and a later diagnosis of autism; FH-Other, infants with a family history of autism and with neurodevelopmental difficulties at age 3 years who did not meet criteria for a clinical diagnosis of autism; FH-TD, infants with a family history of autism and typical development at age 3 years; F-N N290 latency, N290 latency difference between the face and the nonface conditions; No FH, infants with no family history of autism; PGS, polygenic score.
η2 Indicates eta-squared as a measure of the analysis of variance effect size.
Significant differences based on Tukey honest significant difference post hoc test.
Significant differences based on Tukey honest significant difference post hoc test.
Significant differences based on Dunn post hoc test.
Significant differences based on Dunn post hoc test.
Significant differences based on Dunn post hoc test.
η2[H], eta squared based on the H statistic obtained in the Kruskal-Wallis test