Table 4.
Results of independent samples t-tests
| Measure | FXS-ASD M (SD) | FXS-O M (SD) | Test statistic | p-value | Effect size (Cohen’s d) |
|---|---|---|---|---|---|
| Early ASD Risk Markers (AOSI) | |||||
| Total Score – 9m | 16.25 (5.74) | 7.25 (5.32) | t(6) = 0.96 | .38 | 1.63 |
| Total Score – 12m | 13.33 (0.58) | 7.50 (4.93) | t(5) = 1.99 | .10 | 1.66 |
| Marker Score – 9m | 9.25 (2.06) | 6.75 (4.11) | t(6) = 1.09 | .32 | 0.77 |
| Marker Score – 12m | 8.67 (0.58) | 4.00 (2.94) | t(5) = 2.65 | <.05 | 2.20 |
| ASD Severity (ADOS) | |||||
| Total Severity Score – 24m | 7.75 (1.26) | 2.25 (0.96) | t(6) = 6.97 | <.001 | 4.91 |
| SA Severity Score – 24m | 6.75 (1.71) | 1.50 (0.58) | t(6) = 5.82 | <.01 | 4.11 |
| RRB Severity Score – 24m | 8.50 (1.91) | 6.25 (0.96) | t(6) = 2.10 | .08 | 1.49 |
| Temperament Factors (IBQ-R & ECBQ) | |||||
| Surgency – 9m | 5.61 (1.14) | 4.63 (0.51) | t(5) = 1.56 | .18 | 1.11 |
| Surgency – 12m | 4.38 (0.56) | 5.17 (0.37) | t(6) = −2.37 | .06 | 0.44 |
| Surgency – 24m | 3.61 (1.35) | 4.93 (0.57) | t(6) = −1.76 | .13 | 1.27 |
| Negative Affect – 9m | 4.51 (1.01) | 3.26 (0.13) | t(5) = 2.52 | .05 | 1.74 |
| Negative Affect – 12m | 4.22 (0.57) | 3.70 (0.22) | t(6) = 1.70 | .14 | 1.20 |
| Negative Affect – 24m | 2.94 (0.28) | 3.19 (0.18) | t(6) = −1.49 | .19 | 1.06 |
| Effortful Control – 9m | 3.70 (1.05) | 5.31 (0.54) | t(4) = −2.63 | .06 | 1.93 |
| Effortful Control – 12m | 3.74 (1.04) | 4.56 (0.32) | t(5) = −1.53 | .19 | 1.07 |
| Effortful Control – 24m | 3.99 (0.99) | 4.50 (0.31) | t(6) = −0.98 | .37 | 0.70 |
| Change in Surgency | −1.34 (1.22) | 0.30 (0.67) | t(5) = −2.30 | .07 | 1.67 |
| Change in Negative Affect | −1.65 (1.16) | −0.07 (0.29) | t(5) = −2.70 | <.05 | 1.87 |
| Change in Effortful Control | 0.17 (0.25) | −0.81 (0.80) | t(4) = 1.58 | .19 | 1.65 |
| Developmental Level (MSEL) | |||||
| Raw Score Total – 9m | 28.50 (5.00) | 35.75 (8.09) | t(6) = −1.52 | .18 | 1.08 |
| Raw Score Total – 12m | 40.67 (12.22) | 50.75 (8.77) | t(5) = −1.28 | .26 | 0.95 |
| Raw Score Total – 24m | 58.50 (17.71) | 75.75 (17.67) | t(6) = −1.38 | .22 | 0.98 |
| Change in Raw Score Total | 30.00 (12.99) | 40.00 (11.92) | t(6) = −1.14 | .30 | 0.80 |
| Adaptive Abilities (VABS-II) | |||||
| Raw Score Total – 9m | 56.75 (20.27) | 79.25 (19.43) | t(6) = −1.61 | .16 | 1.13 |
| Raw Score Total – 12m | 76.67 (28.45) | 104.50 (19.43) | t(5) = −1.55 | .18 | 1.14 |
| Raw Score Total – 24m | 138.25 (59.47) | 191.50 (30.91) | t(6) = −1.59 | .16 | 1.12 |
| Change in Raw Score Total | 81.50 (42.19) | 112.25 (20.56) | t(6) = −1.31 | .24 | 0.93 |