Table 6.

Parameters of trajectories of vocabulary growth in conditional models, examining the influence of number of medical complications and processing speed (RT) in PT (n = 69) children. Intercept estimates (SE) indicate predicted vocabulary size at 30 months; linear and quadratic parameter estimates (SE) indicate rate and acceleration of developmental change, respectively.

	Model 7: Medical Complications	Model 8: RT	Model 9: Medical Complications × RT
Model fit (−2LL)	3218.7	3211.7	3202.9
No. parameters	16	16	22
Fixed effects
Intercept	1301.5 (172.4)**	1784.2 (354.7)**	1119.6 (724.5)
Linear	148.0 (24.9)**	132.6 (53.3)*	−41.8 (106.0)
Quadratic	4.1 (1.2)**	0.9 (2.5)	−8.1 (5.0)
Med Comp × Intercept	−75.2 (40.2)#	--	212.1 (205.6)
Med Comp × Linear	−8.8 (5.8)	--	55.6 (30.2)#
Med Comp × Quadratic	−0.2 (0.3)	--	2.4 (1.5)*
RT × Intercept	--	−1.0 (0.4)*	0.2 (0.9)
RT × Linear	--	−0.1 (0.1)	0.3 (0.1)#
RT × Quadratic	--	0.1 (0.1)	0.1 (0.1)*
Med Comp × RT × Int	--	--	−0.3 (0.3)
Med Comp × RT × Linear	--	--	−0.1 (0.1)*
Med Comp × RT × Quad	--	--	−0.1 (0.1)*
Random Effects
Within person	2273.0 (460.1)**	1961.3 (415.5)**	1969.8 (412.8)**
Intercept	18987.3 (3256.3)**	16779.9 (2859.7)**	16291.3 (2798.7)**
Linear	111702.4 (19975.8)**	102430.2 (17709.5)**	99927.8 (17965.5)**
Quadratic	253990.7 (46531.1)**	239614.0 (43665.0)**	227069.3 (41457.7)**

Note:

^#p < .07,

^*p < .05,

^**p < .01