Psychometric properties of the Post-traumatic Growth Inventory in the context of the COVID-19 pandemic: Bifactor model invariance

The Posttraumatic Growth Inventory (PTGI; Tedeschi & Calhoun, 1996) assesses growth experiences following traumatic events, such as those experienced during the COVID19 pandemic. However, its factor structure is still under debate, suggesting that a bifactor model might best represent the structure of the test. This study examined the psychometric properties of this instrument with a sample of 615 Peruvian adults. Confirmatory factor analyses revealed that a bifactor model, which included a general factor and five specific factors, proved to be the best fit to the data (SBSχ2 (df)= 909.26(184), CFI =1, RMSEA =.066, SRMR =.046). We found evidence of configural invariance between the group that reports deceased relatives by COVID19 and the group that does not. In addition, adequate internal consistency indices were found. This study supports adequate psychometric properties of the PTGI.