. Author manuscript; available in PMC: 2013 Mar 31.

Published in final edited form as: J Autism Dev Disord. 2007 Dec 5;38(6):1104–1111. doi: 10.1007/s10803-007-0495-9

Table 2.

HLM growth trajectory model of HC z-scores sex differences

Growth parameter	Fixed effect	Coefficient	SE	t (df)	p
HC z-score at 12 months	Intercept	1.06	0.18	5.87 (76)	<0.01
HC z-score at 12 months	Sex	−0.55	0.25	−2.19 (76)	0.03
Slope (birth to 12 months)	Intercept	0.09	0.01	6.78 (76)	<0.01
Slope (birth to 12 months)	Sex	−0.03	0.02	6.78 (76)	0.09
Slope (12–24 months)	Intercept	−0.02	0.01	−1.71 (76)	0.09
Slope (12–24 months)	Sex	0.04	0.02	2.43 (76)	0.02