The psychometric properties of the Peruvian traumatic grief inventory-self report plus (TGI-SR+) in bereaved people

BACKGROUND: Several instruments have been developed to measure Prolonged Grief Disorder (PGD). However, the Traumatic Grief Inventory-Self Report Plus (TGI-SR+) is one of the few that measures PGD according to diagnostic criteria-sets defined in the Diagnostic and Statistical Manual of Mental Disorders, Text-revised Fifth Edition (DSM-5-TR) and the International Classification of Diseases, 11th Revision (ICD-11). The TGI-SR+ has been validated in several languages. However, it has not been validated yet Peruvian. OBJECTIVE: This research evaluated the psychometric properties of the Peruvian TGI-SR+. METHOD: The sample consisted of 516 Peruvians who had lost a loved one ≥ 6 months ago. For DSM-5-TR and ICD-11 PGD items separately, we examined the factor structure, internal consistency, convergent validity, known-groups validity, and determined optimal cutoff scores to identify probable PGD caseness. RESULTS: A one-factor model fit the data best for the DSM-5-TR PGD items, however the fit was not acceptable for the ICD-11 PGD items. Although some items showed low factor loadings across both sets, internal consistency was good. Convergent validity was established through strong correlations between DSM-5-TR and ICD-11 PGD levels and measures of posttraumatic stress and depression. Known-groups validity was partially supported, with DSM-5-TR and ICD-11 PGD intensity relating to both the cause of death and the kinship to the deceased. The optimal cutoff score for identifying probable DSM-5-TR is ≥ 70 and for the ICD-11 PGD is ≥ 76 using the total TGI-SR+ score. CONCLUSION: This study represents the first validation of the TGI-SR+ in Latin America, contributing to the understanding of bereavement in the Global South. The Peruvian TGI-SR+ demonstrates to be a reliable and valid measure to assess DSM-5-TR PGD and ICD-11 PGD severity.