Table 3b.

Multivariable zero-inflated negative binomial regression model assessing the association between risk factors and PCL-5 Hyperarousal subscale at 3-months post-injury (n=405)

	FC	95% CI	p-value	OR	95% CI	p-value
PC1	.94	0.88–0.99	.031	1.27	0.99–1.64	.06
ICV (standardized)	1.13	1.00–1.27	.049	.79	0.49–1.26	.31
Male (ref: Female)	.99	0.82–1.19	.89	.96	0.44–2.11	.92
Black (ref:White/Other)	1.21	0.99–1.48	.063	1.48	0.63–3.44	.37
Hispanic (ref: non-Hispanic)	1.09	0.89–1.33	0.43	1.66	0.66–4.18	.28
Education (y)	.96	0.93–0.99	0.013	1.11	0.98–1.25	.09
Any psychiatric history (ref: None)	1.16	0.96–1.40	0.128	2.06	0.77–5.52	.15
Any prior TBI (ref: None)	1.17	0.997–1.37	0.055	1.35	0.68–2.67	.39
Violent injury cause* (ref: Accidental)	1.05	0.79–1.39	0.76	--	--	--
PCL-5 Hyperarousal at week 2	1.07	1.05–1.08	<0.001	1.35	1.20–1.50	<0.001

PC1: first principal component that explained 73.8% of the variance in the regional volumes of the insula, superior frontal cortex, and rostral and caudal anterior cingulate

FC: Estimated fold change with 95% confidence interval of the predictor variable associated with severity of hyperarousal symptoms when the symptoms are present.

OR: Estimated odds ratio with 95% confidence interval of the predictor variable associated with presence (non-zero scores) vs. absence (zero scores) of hyperarousal symptoms.

^*Injury cause was not modeled in the zero-inflation part due to zero-count in one of the cells which would lead to an infinite confidence interval.