Psychometric properties of the Trauma Symptom Inventory (TSI; Briere, 1995)

Type of Instrument

The Trauma Symptom Inventory (TSI) is a test containing 100 items claiming to measure ‘posttraumatic stress and other psychological sequelae of traumatic events’. It was devised to be used in the assessment of ‘acute and chronic traumatic symptomatology’, such as rape, physical assault, spouse abuse, major accidents, combat trauma, natural disasters and the enduring effects of childhood abuse and early childhood trauma (Briere, 1995).

The TSI has 3 validity scales and 10 clinical scales that assess a broad range of psychological symptoms including those related to Posttraumatic Stress Disorder (PTSD) and Acute Stress Disorder (ASD) plus intra and interpersonal difficulties associated with chronic psychological trauma. The test is self-administered and is intended for a fifth grade and above reading level (Briere 1995). Items are scored on a four point scale with 0 = Never through to 3 = Often, and are rated in terms of frequency of occurrence over the previous six months. Due to this time frame the TSI was ‘not intended to generate a DSM IV PTSD diagnosis’. The TSI takes approximately 20 minutes to complete and around 15 minutes to score (Briere and Elliott, 1997).

Table 1 lists the scales along with their internal reliability correlation coefficient for the standardised sample (N = 836), and the number of items for each scale (Briere, 1995).

Table 1. Clinical scales & Mean alpha coefficients & number of test items for each scale.

(Source: Briere 1995) *RL = 5 independent items & 5 combined *INC = 20 combined items

The Mean alpha correlation scores show a high reliability on all scales except for the INC validity scale.

Briere (1995), states that the mean intercorrelations of the 10 clinical scales for the ‘TSI are internally consistent with Mean alpha coefficients’ of .86 for the standardised (N=836), .87 for the clinical (N=370), .84 for the university (N=279), and .85 for the military samples (N=3659).

Runtz & Roche (1999), in their study of a group of 775 ‘previously victimized’ Canadian university women calculated internal consistency reliabilities for the clinical scales of the TSI. They found that the TSI internal consistency is strong (alpha = .64) ‘as all reliabilities were above alpha = .80, except for TRB’. They cite other researchers who found that TRB scales have lower reliability with student samples. In their sample more than 90% of those surveyed were aged under 25.

Norms

The standardisation sample Norms and T scores were derived from the general population in a mail out of 836 American males and females 18 years and over. The mean age of subjects 47.3 years (SD = 16.6%) range = 18-88). Of the sample 57.1% were married, 16.6% separated, 16.5% single, 50.8% males, 77.5% Caucasian, 10.3% African American, 6.1% Hispanic, 2.9% Asian, and 2.3% Native American. Normative data for the TSI scales were derived from the raw score data of the above standardisation sample. There are separate norms for a sample of 3,659 male and female navy recruits (Briere, 1995). Analyses of variance revealed differences in age, sex and race. Based upon age and sex groupings normative data were derived with Linear T scores having a mean of 50 and a standard deviation of 10. Separate norms have been calculated for age 18 – 55 and 55 and over for both male and females.

The Runtz & Roche (1999) study confirmed Briere’s (1995) observation that student samples report ‘greater difficulties on many of the TSI scales’ than a survey of the general population. The overall means for the 10 TSI scales were higher than the standardisation sample of females 18 to 54, compared to the student sample. They had an average of .42 SD (ranging from .15 to .81).

Briere, J. (1995). Trauma Symptom Inventory (TSI) Professional Manual, Psychological Assessment Resources, Inc.

Briere, J., & Elliott D.M. (1997) Psychological Assessment of Interpersonal Victimisation Effects in Adults and Children. Psychotherapy, 34, 353 – 364.

Norris, F.H., & Raid, J.K. (1997). Standardised self-report measures of civilian trauma and posttraumatic stress disorder. In J.P. Wilson and T.M Keane (Eds.) Assessing psychological trauma and PTSD. The Guilford Press: New York.

Runtz, M.G., & Roche, D.N. (1999) Validation of the Trauma Symptom Inventory in a Canadian sample of university women. Journal of the American Professional Society on the Abuse of Children, 4, 69 – 80.

Above written by: Mr. Philip Byrne

Reviewed, edited and approved by: Dr. Grant J. Devilly