Table 4.

Clinical variables associated with Autism Parenting Stress Index (APSI) (N = 46): linear regression model.

Independent Variables	Linear Regression Model
	p	SE	95% C.I.
Age (months)	0.221	0.126	−0.08–0.33
Sex, Male vs. Female a	0.575	0.186	−0.48–0.85
Oppositional index of CPRS	<0.001	0.524	0.23–0.81
ADHD index of CPRS	0.029	0.410	0.04–0.77
Hyperactive–Impulsive index of CPRS	0.125	−0.273	−0.62–0.08
Somatic complaints index of CBCL	0.004	0.322	0.11–0.53
Worry about illness index of IAS	<0.001	0.481	0.26–0.70
Disorder of initiating and maintaining sleep index of SDSC	0.010	0.396	0.10–0.69
Sleep–wake transition disorder index of SDSC	<0.001	0.609	0.28–0.93

^a: reference level. Bold indicates significant values (p < 0.05). Multivariate model fit measures: (R² = 0.759, adjusted R² = 0.685), VIF < 4.0 for all the independent variables.