Psychometric Properties of the Revised Version of the Prolonged Grief Disorder Scale (PG-13-R): A Methodological Study in the Iranian Population.

Prolonged grief disorder has recently been officially introduced as a new mental disorder. This study aimed to validate the Persian version of the revised Prolonged Grief Scale (PG-13-R). This study was conducted among the general population in Shahroud, Iran, during 2023. Employing face and content validity, along with exploratory and confirmatory factor analyses (EFA), the study validates the PG-13-R. Average variance extracted value showed an acceptable convergent validity. The EFA reveals a singular factor structure explaining 60.541% of the variance in prolonged grief disorder, and the confirmatory factor analysis demonstrates an excellent model fit. Internal consistency, evaluated through Cronbach's alpha and MacDonald's omega, highlights the scale's reliability. The Persian version of PG-13-R had acceptable composite reliability. Stability is confirmed by an intra-class correlation coefficient. In conclusion, the Persian PG-13-R displays satisfactory validity and reliability to assessing prolonged grief symptoms in the Iranian population.