. 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 1.

HLM growth trajectory model of Head Circumference (HC) Z-scores

Growth parameter	Coefficient	SE	t (df)	p
HC z-score at 12 months	0.84	0.12	6.83 (76)	<0.01
Slope (birth to 12 months)	0.08	0.01	8.57 (76)	<0.01
Slope (12–24 months)	−0.01	0.01	−0.46 (76)	0.65