Table 5.

Linear regression among females and males with measures of symptom severity as dependent variables and AOW as the primary covariate

Available case analysis (n ≤ 490)	Females								Males
	SCQ total				ADI-R nonverbal total				SCQ total				ADI-R nonverbal total
AOW (mo)	n	B	CI	p	n	B	CI	p	n	B	CI	p	n	B	CI	p
Unadjusted	49	.31	(− .27 to .88)	.29	36	.64	(− .59 to 1.87)	.30	166	.72	(.34 to 1.11)	< .001	105	.67	(.15 to 1.19)	.01
Adjusted for all*	23	− .52	(− 1.44 to .39)	.24	22	1.15	(− .91 to 3.21)	.25	80	.51	(− .10 to 1.12)	.10	53	.37	(− .487 to 1.22)	.39

Multiple imputation (n = 393)	SCQ total				ADI-R nonverbal total				SCQ total				ADI-R nonverbal total
AOW (mo)	n	B	CI	p	n	B	CI	p	n	B	CI	p	n	B	CI	p
Unadjusted	87	.21	(− .16 to .57)	.27	87	.87	(− .30 to 2.04)	.15	306	.28	(.07 to .49)	.008	306	.98	(.41 to 1.54)	.001
Adjusted for all*	87	.16	(− .22 to .54)	.40	87	1.02	(− .17 to 2.21)	.09	306	.31	(.09 to .54)	.007	306	.78	(.18 to 1.37)	.01

AOW age for onset of independent walking. Dependent variables: SCQ Social Communication Questionnaire, ADI-R Autism Diagnostic Interview-Revised. Results based on available case analysis of the main sample, and multiple imputation of n = 393 participants with data on at least one dependent variable. B unstandardized regression coefficient, CI 95% confidence interval, p p-value

*Adjusted for the covariates: age, nonverbal IQ, prematurity, ethnicity, maternal and paternal age