. 2016 Feb 4;33(23):2125–2132. doi: 10.1089/neu.2015.4320

Table 1.

Results of Weighted Zero-Inflated Negative Binomial Regression Evaluating Effects of Sex, Pre-Deployment General Distress, Pre-Deployment Traumatic Brain Injury History, Deployment Stress Severity, and Deployment-Acquired Traumatic Brain Injury^* on Presence (Yes/No; Adjusted Odds Ratio) and Severity (for Nonzero Scores; Fold Change) of Post-Deployment Post-Concussive Symptoms in Soldiers With and Without Mild Traumatic Brain Injury (n = 4518)

	3 months post-deployment (T2)						9 months post-deployment (T3)
	AOR^a	95% CI	p	FC^b	95% CI	p	AOR^a	95% CI	p	FC^b	95% CI	p
Female sex	1.34	0.50–3.58	0.551	1.19	1.07–1.33	0.002	1.46	0.91–2.32	0.110	1.23	1.10–1.37	0.001
Pre-deployment past-month general distress	1.39	1.11–1.73	0.005	1.01	1.01–1.01	<0.001	1.14	1.06–1.22	0.001	1.01	1.01–1.01	<0.001
Deployment stress severity	1.09	1.00–1.19	0.050	1.05	1.04–1.06	<0.001	1.10	1.04–1.16	0.001	1.04	1.03–1.05	<0.001
Any lifetime pre-deployment TBI with LOC	1.34	0.91–1.98	0.133	1.10	1.05–1.15	<0.001	1.59	1.19–2.11	0.002	1.10	1.03–1.17	0.004
Any deployment-acquired mild TBI	2.88	1.64–5.05	<0.001	1.31	1.24–1.39	<0.001	2.92	1.82–4.68	<0.001	1.23	1.16–1.31	<0.001

AOR, adjusted odds ratio; CI, confidence interval; FC, fold change. Post-concussive symptoms (PCS) were measured with the PCS-8, which assessed severity of: balance problems or dizziness, sensitivity to noise, sensitivity to light, memory problems, irritability, difficulty concentrating, headaches, and feeling tired out or being easily fatigued.

^{^*}

Models also adjust for age group (<30 years vs. older), race, ethnicity, brigade combat team, and number of previous deployments.

^{^a}

For ease of interpretation, AORs reported in the table indicate odds of a nonzero score on the PCS-8 (i.e., presence of any symptoms) that are associated with each hypothesized predictor. These AORs were calculated by taking the inverse of the AORs for odds of a zero score (not shown in Table).

^{^b}

FCs indicate the fold increase or decrease in PCS-8 score associated with each predictor when any symptoms are present (i.e., when PCS-8 score is nonzero).