Psychometric properties of the Prolonged Grief Disorder-13 (PG-13) in bereaved Swedish parents

•The study showed that PG-13 is a valid measure of Prolonged Grief Disorder.•A principal component analysis supported a one-factor structure of the PG-13.•The criteria for Prolonged Grief Disorder were met by 16% of bereaved parents. This study aimed to validate the Swedish version of the Prolonged Grief Disorder-13 tool (PG–13) by examining its psychometric properties, including factor structure, discriminant and concurrent validity. The PG–13 was assessed in a sample of Swedish parents who had lost a child to cancer 1–5 years previously. The sample included 225 parents (133 mothers and 92 fathers) with a mean age of 46.02 years (SD = 8.15) and 16.0% met the criteria for Prolonged Grief Disorder (PGD). A principal component analysis was performed, and the results supported a one-factor structure of the PG-13. The PG–13 was shown to have high internal consistency and intelligible associations with concurrent psychological symptoms and grief rumination as well as with known risk factors for PGD. These results indicate satisfactory psychometric properties of the instrument, thus supporting the use of the PG-13 as a valid measure of PGD.