. Author manuscript; available in PMC: 2019 Jan 1.

Published in final edited form as: J Head Trauma Rehabil. 2018 Jan-Feb;33(1):E18–E27. doi: 10.1097/HTR.0000000000000325

Table 5.

Initial status and rate of change over 12-months for each of the cognitive domains (n=175).

		Cognitive Domain

		Processing Speed/Executive Function		Memory		Verbal Fluency

		Full	Final	Full	Final	Full	Final
*Initial Status*	Intercept	.11 (.09)	.11 (.09)	.06 (.12)	.05 (.11)	−.27 (.09)^b	−.28 (.09)^b
	mTBI	−.44 (.16)^b	−.42 (.16)^a	−.48 (.21)^a	−.42 (.20)^a	−.42 (.16)^b	−.41 (.16)^b
	cmTBI	−.97 (.17)^c	−.94 (.17)^c	−.91 (.22)^c	−.91 (.22)^c	−.71 (.17)^c	−.68 (.17)^c
	msevTBI	−1.87 (.14)^c	−1.82 (.14)^c	−1.98 (.18)^c	−2.00 (.17)^c	−1.43 (.14)^c	−1.39 (.13)^c
	IQ (centered)	.03 (.01)^c	.03 (.00)^c	.03 (.01)^b	.04 (.00)^c	.02 (.01)^a	.02 (.00)^c
	IQ x mTBI	−.01 (.01)		−.01 (.02)		.01 (.01)
	IQ x cmTBI	.02 (.01)		.00 (.02)		.02 (.01)
	IQ x msevTBI	−.01 (.01)		.01 (.01)		.01 (.01)
*Rate of Change*	Time (months)	.03 (.01)^c	.03 (.00)^c	.022 (.01)	.03 (.01)^a	.01 (.01)	.01 (.01)
	Time x mTBI	.02 (.01)	.02 (.01)	.03 (.02)	.02 (.02)	.02 (.01)	.02 (.01)
	Time x cmTBI	.05 (.01)^c	.05 (.01)^b	.06 (.02)^a	.06 (.02)^a	.04 (.02)^a	.04 (.02)^a
	Time x msevTBI	.11 (.01)^c	.10 (.01)^c	.12 (.02)^c	.12 (.01)^c	.08 (.01)^c	.07 (.01)^c
	Time x IQ	−.00 (.00)		.00 (.00)		.00 (.00)
	Time x IQ x mTBI	.00 (.00)		.00 (.00)		.00 (.00)
	Time x IQ x cmTBI	.00 (.00)		−.00 (.00)		−.00 (.00)
	Time x IQ x msevTBI	.00 (.00)		−.00 (.00)		.00 (.00)
Goodness of Fit^d	AIC	903.4	836.8	1282.1	1218.7	910.4	842.5

Abbreviations: mTBI, mild TBI; cmTBI, complicated mild TBI; msevTBI, moderate to severe TBI.

Note. SAS Proc Mixed, Restricted ML. Full Level 2 conditional growth model includes the effects of TBI severity (controls as reference group), WTAR IQ (centered on population mean of 100), and their interaction on both initial status and rate of change; Final model includes only significant predictors from full model. ‘Intercept’ and ‘Time’ refer to average performance at one-month post-injury and rate of change per month, respectively, for controls with an average WTAR predicted IQ of 100 (with significance indicating that these values significantly differ from 0). Parameter estimates and significance testing for TBI groups are relative to controls (i.e., significance indicates that they significantly differ from those without head injury).

p<.05;

p<.01;

p<.001

Smaller value indicates better model fit.