Psychometric Evaluation of the Persian Version of the Post-Traumatic Symptom Scale: Exploratory and Confirmatory Factor Analysis

Abstract

Background: Iranian youth encounter numerous stressors, including accidents, suicide, and unemployment, heightening their risk for posttraumatic stress disorder (PTSD). It's crucial to assess, diagnose, and treat PTSD in this demographic. Objectives: This study aimed to evaluate the factor structure and validate the Post-Traumatic Symptom Scale (PTSS). Methods: A cross-sectional approach was employed for the validation of the PTSS in Bandar Abbas, 2022, with a sample of 901 young residents selected via random cluster sampling. Data were gathered using the PTSS and the Mississippi Scale for Posttraumatic Stress Disorder (MSPSS). Validation of the scale encompassed content validity, concurrent validity, and factor analysis. Reliability assessments included internal consistency, test-retest, and split-half reliability. The optimal cut-off point was identified through receiver operating characteristic (ROC) curve analysis and the Youden Index. Results: The PTSS demonstrated robust face and content validity, evidenced by impact factor (1.6 < impact factor < 3.6), content validity ratio (CVR = 0.68 to 0.91), and Content Validity Index (CVI = 0.70 to 0.94). The PTSS's concurrent validity with the MSPSS was positively strong (r = 0.64, P < 0.001). Factor analyses, both exploratory (EFA) and confirmatory (CFA), substantiated a four-factor model of the PTSS, accounting for 56.288% of the variance (19% for arousal and reactivity, 14% for negative alterations in cognitions and mood, 11% for avoidance, and 11% for intrusion). The scale's overall Cronbach's alpha was 0.87, with subscales ranging from 0.77 to 0.88. Test-retest reliability stood at 0.81 (P < 0.01), and split-half reliability at 0.81. The PTSS's optimal cut-off for PTSD diagnosis was 60, delivering a sensitivity of 0.70, specificity of 0.99, and Youden Index of 0.69. Conclusions: The PTSS proves to be a reliable and valid instrument for assessing posttraumatic stress symptoms among young Iranians, offering a useful resource for researchers and practitioners in the prevention and treatment of PTSD.