Abstract

The purpose of this study is to develop a short form of the Posttraumatic Growth Inventory-Expanded (PTGI-X) using Item Response Theory and factor analysis. The PTGI-X was developed to address the psychometric limitations of the Posttraumatic Growth Inventory (PTGI), which is the most widely used measure of positive psychological changes following traumatic events. However, issues related to measurement invariance across religious and non-religious groups and differential item functioning (DIF) remained when using the PTGI. Therefore, this study developed a short-form scale with high validity and practicality by employing not only factor analysis but also Item Response Theory (IRT) techniques to analyze the characteristics of individual items in detail. Twelve items with high validity were selected using confirmatory factor analysis, multi-group confirmatory factor analysis, and IRT-based methods. Compared with the original scale, the short form scale exhibited higher information values with fewer items, indicating greater efficiency, and showed significant correlations with deliberate rumination and emotional approach coping. Thus, this study addressed the psychometric limitations of the scale by proposing a short form of the PTGI-X. It is expected that the findings will contribute to a valid and efficient measurement of posttraumatic growth, thereby enhancing its applicability in both research and clinical settings.