New tools to assess DSM-5-TR and ICD-11 prolonged grief disorder in research and practice: Research in about 1000 bereaved people

Background When grief reactions are so intense and persistent that they impair daily functioning, a diagnosis of a prolonged grief disorder (PGD) may apply. Slightly differing criteria-sets for PGD are included in the two most commonly used classification systems in mental healthcare: the ICD-11 and DSM-5-TR. Rationale We examined psychometric properties of two new measures that assesses both criteria-sets for PGD: (i) a survey called the Traumatic Grief Inventory-Self Report Plus (TGI-SR+) and (ii) the clinical interview-version named the Traumatic Grief Inventory-Clinician Administered (TGI-CA). Design The TGI-SR+ was evaluated in two Dutch samples. Sample 1 consisted of 278 adults, bereaved by various causes. Sample 2 included 270 adults who lost loved ones in a traffic accident. All participants completed online surveys. The psychometric properties of the TGI-CA were examined in 211 Dutch and 222 German adults, bereaved by various causes, using telephone interviews. Evaluation We found support for a 1-factor model for DSM-5-TR and ICD-11 PGD. The items demonstrated good internal consistency and temporal stability. Associations between PGD, posttraumatic stress, and depression levels supported convergent validity. Associations between demographic/loss-related variables and PGD symptoms supported known-groups validity. Optimal clinical cut-offs for the TGI-SR+ total score were ≥71 for probable caseness of DSM-5-TR PGD and ≥75 for ICD-11 PGD. When using the TGI-CA, rates of probable caseness for DSM-5-TR PGD were lower than ICD-11 PGD. Conclusion The TGI-SR+ and TGI-CA are reliable and valid to assess DSM-5-TR and ICD-11 PGD in research and practice. Both instruments are freely available in multiple languages