1. Factor Analysis of the Trauma Symptom Inventory Using a Military Sample
Angela Sekely1, Julia Daugherty1, Hana Kuwabara1, Andrea Mejia1, Cuixian Chen2,
Yishi Wang2 and Antonio E Puente1
1 UNCW Department of Psychology
2 UNCW Department of Mathematics and Statistics
Introduction
Exploratory Factor Analysis
Confirmatory Factor Analysis
Exploratory Factor Analysis (EFA) allows you to analyze how items load onto non-hypothesized variables. C
Principle Components Analysis revealed the presence of two components with eigenvalues exceeding 1, explaining 72.25% of the variance collectively
Monte Carlo Parallel Analysis revealed only 2 factors exist with eigenvalues exceeding corresponding criterion values for a randomly generated data matrix
Confirmatory Factor Analysis (CFA) is used to test specific hypothesis on the structure of underlying variables.
Since the strength of the relationship between factor 1 and factor 2 is moderate (r=.53), oblimin rotation was appropriate.
Of more than two million veterans that have been involved in the wars in Iraq and Afghanistan, it has been estimated that 12% of those returning from Afghanistan and 18% of those returning from Iraq report having experienced Post Traumatic Stress Disorder (PTSD). A
PTSD has been measured using a variety of instruments, and the Trauma Symptom Inventory (TSI) is frequently used clinically. B
Though 228 studies are found in PsychINFO, few psychometric studies on TSI have been conducted and none have been completed using military samples.
The purpose of this study is to provide insight into the underlying factors of the TSI, using both Exploratory and Confirmatory Factor Analyses.
Visual Representation of the 2 Factor Oblimin CFA
Kaiser’s Criterion
Monte Carlo Parallel Analysis
Number of variables:     10
Number of subjects:     334
Number of replications: 100 
Eigenvalue #     Random Eigenvalue     Standard Dev
1                             .0355
2                             .0337
3                             .0265
4                             .0284
5                             .0253
6                             .0211
7                             .0190
8                             .0227
9                             .0261
10                             .0391
Monte Carlo PCA for Parallel Analysis
©2000 by Marley W. Watkins. All rights reserved.
******************************************************
Participants
Psychological testing results of 1,010 military personnel were compiled by the Roger W. Sperry Neuropsychology Laboratory in collaboration with Carolina Psychological Health Services.
The demographics represent the 633 participants that completed cases of the TSI.
It can be seen that the majority of participants are young, Caucasian, male, high school graduate veterans of Iraq and Afghanistan with blast injuries.
Age, Education, and Number of Deployments
“Elbow” of the scree plot was revealed at the third factor
Two factors should be selected
Demographic
Mean
Median
Mode
Range SD
Age
26.06
24.00
22.00
18-62
6.19
Education (years)
12.48
12.00
9-18
1.13
Number of Deployments
1.93
2.00
0-10
1.31
Scree Plot
Conclusions
EFA yielded 2 independent factors: Trauma/Dysphoria and Self
CFA demonstrated that both components showed a number of strong loadings
All variables loaded substantially onto the components
Consistent with the TSI literature among additional populations (e.g. civilians) D,E
Inconsistent with factor analyses on PTSD diagnosis that have yielded four- and five-factor models
TSI does not map well onto PTSD criteria in DSM-5 diagnosis
TSI includes both PTSD-related and other trauma-related information E
Ethnicity
Location of Deployment
All items load strongly onto the first rotation, just four load onto the second rotation
2 Factor Unrotated EFA
Resources
Factor 1
Factor 2
ISR
.887 AA
.851
DIS
.836
TRB
.832
.389 DA
.807 AI
.804 D
.800 IE
.799
-.341 SC
.654
.474
DSB
.585
.717
A Litz, B. T. & Schlenger, W. E. (2009). PTSD in service members and new veterans of the Iraq and Afghanistan wars: A bibliography and critique. PTSD Research Quarterly, 20(1), 1-8.
B National Center for PTSD (2014). Assessment. US Department of Veterans Affairs. Retrieved from
C Hurley, Scandura, Schriesheim, Brannick, Seers, Vandenberg & Williams (1997). Exploratory and confirmatory factor analysis: Guidelines, issues, and alternatives. Journal of Organizational Behavior, 18(6),
D Briere, J. (1995). Trauma Symptom Inventory Professional Manual. Odessa, FL: Psychological Assessment Resources.
E Snyder, J. J., Elhai, J. D., North, T. C., & Heaney, C. J. (2009). Reliability and validity of the Trauma Symptom Inventory with veterans evaluated for posttraumatic stress disorder. Psychiatry Research, vol. 170,
Trauma Symptom Inventory
The TSI is composed of the following 10 Clinical and 3 Validity Scales:
Clinical Scales:
Anxious Arousal (AA)
Depression (D)
Anger/Irritability (AI)
Intrusive Experiences (IE)
Defensive Avoidance (DA)
Dissociation (DIS)
Sexual Concerns (SC)
Dysfunctional Sexual Behavior (DSB)
Impaired Self Reference (ISR) Tension Reduction Behavior (TRB)
Validity Scales:
Response Level (RL)
Atypical Response (ATR)
Inconsistent Response (INC)