Table 3.
Difference in Estimated Differences
| Mean Change ASD | Mean Change TD | Difference in Differences (ASD – TD) | Statistic | Effect Size | |
|---|---|---|---|---|---|
|
| |||||
| Social Composite | 9.20*** (5.54, 12.86) | 14.12*** (12.06, 16.19) | −4.92* (−9.12, −0.71) | z = −2.29* | 0.42 |
| Emotion and Eye Gaze | 1.11 (−0.06, 2.28) | 1.14** (0.48, 1.80) | −0.03 (−1.37, 1.31) | z = −0.04 | 0.01 |
| Communication | 5.30*** (3.46, 7.14) | 8.03*** (7.00, 9.07) | −2.73* (−4.85, −0.61) | z = −2.53* | 0.47 |
| Gestures | 2.79** (1.24 4.35) | 4.95*** (4.07, 5.83) | −2.16* (−3.95, −0.37) | z = −2.36* | 0.43 |
| Speech Composite a | 3.99** (1.69, 9.43) | 4.05*** (2.62, 6.26) | −0.98* (−2.59, 0.37) | z = −0.03 | 0.01 |
| Sounds a | 4.00** (1.69, 9.47) | 3.71*** (2.39, 5.76) | 1.08 (0.41, 2.84) | z = 0.15 | 0.03 |
| Symbolic Composite | 4.56*** (2.93, 6.18) | 5.93*** (5.01, 6.84) | −1.37 (−3.23, 0.50) | z = −1.44 | 0.26 |
| Understanding a | 5.24** (1.87, 14.70) | 3.11*** (1.83, 5.28) | 1.68 (0.53, 5.37) | z = 0.88 | 0.16 |
| Objects | 2.77*** (1.77, 3.76) | 4.14*** (3.58, 4.70) | −1.37* a (−2.51, 0.23) | z = −2.35* b | 0.43 |
| Total Score | 15.74*** (10.09, 21.38) | 24.80*** (21.61, 27.99) | −9.07** (−15.55, −2.58) | z = −2.74** | 0.51 |
*
p < .05
**
p < .01
***
p < .001
a
Negative binomial regression was used due to a score of 0 at visit 9-month visit for ~50% of participants.
b
These results are no longer significant (p > .05) when controlling for nonverbal developmental quotient (NVDQ). See Supplemental Table 2 for results controlling for NVDQ.