The Posttraumatic Growth Inventory: Factor structure and invariance among persons with chronic diseases.

OBJECTIVE: The Posttraumatic Growth Inventory (PTGI) assesses positive changes after a traumatic or serious life crisis. However, there are differing views regarding its factor structure and little understanding if it captures the positive changes experienced among individuals diagnosed with a chronic disease. Using confirmatory factor analysis (CFA), the proposed five-factor structure and measurement invariance of the PTGI was examined using two chronic illness samples: arthritis and inflammatory bowel disease (IBD). METHOD: Individuals diagnosed with arthritis (n = 301) or IBD (n = 544) recruited from the community and the Internet completed the PTGI. Using a pooled sample, CFA tested five hypothesized models of the underlying factors structure of the PTGI. A stepwise procedure for testing the measurement invariance across the two groups evaluated the factor structure, factorial invariance, and latent mean invariance. RESULTS: Using the pooled sample, the CFA supported the hypothesized five-factor model, revealing the PTGI is multidimensional. Multigroup CFA supported invariance of the PTGI across the two groups although there were significant differences in latent means. CONCLUSIONS: The findings support that the PTGI assesses five related dimensions of PTG and that different chronic disease groups experience different types of positive changes. PTG may therefore be relevant as a meaningful treatment goal for people with chronic diseases as it is for people affected by other traumatic events.