Evaluating the Factor Structure of the Persian Version of Posttraumatic Growth Inventory in Cancer Patients

Abstract

Purpose: This study aimed to assess the factor structure of the Persian version of posttraumatic growth inventory (P-PTGI). Methods: Participants included 272 Iranian people of Azari ethnicity (111 women and 161 men), aged between 21 and 91 years (mean 52.65 years), who were diagnosed with cancer and were referred to the oncology department of the university hospital. The P-PTGI was assessed to determine the construct validity, using various indices of confirmatory factor analysis and standardized lambda coefficient, followed by further assessment of the discriminant and convergent validities by using the structural equation model. LISREL 8.8 for Windows and SPSS were used for data analysis. Results: The calculated values of comparative fit index, incremental fit index, normed fit index, and non-normed fit index > .90 and the values of standardized root-mean-square residual < .08 indicate an acceptable fit for the original PTGI. Considering that the values of average variance extracted (.52–.74) were greater than the square of correlation coefficients between the five dimensions of P-PTGI, discriminant validity was approved. Convergent validity was confirmed through a high value of standardized lambda coefficient (.52–.92) between the items and their related factors. Conclusions: This study revealed that P-PTGI has an acceptable validity and reliability for posttraumatic growth assessment in Iranian cancer patients and its factor structure is similar to that of the original form developed by Tedeschi and Calhoun. Keywords: cancer, posttraumatic, validity