Development of the international prolonged grief disorder scale for the ICD-11: Measurement of core symptoms and culture items adapted for chinese and german-speaking samples

Background: Prolonged grief disorder (PGD) is a new mental health disorder included in the WHO ICD-11 however, the operationalization of the guidelines still needs to be empirically validated, particularly in different cultural contexts. Here we provide a preliminary validation study of the new International Prolonged Grief Disorder Scale (IPGDS) that serves to be the first self-report questionnaire directly based on the ICD-11 PGD and contains culturally adapted items. Methods: In addition to core symptom items new culturally specific items were developed in two phases. Phase 1: key informant interviews with 10 German-speaking and 14 Chinese experts in grief and mental health, followed by a focus group with four bereaved German-speaking participants. Phase 2: 214 German-speaking and 325 Chinese bereaved participants completed self-report questionnaires. Results: Phase 1 resulted in 19 potential culturally relevant items (e.g. feeling stuck in grief). Phase 2 exploratory factor analysis confirmed the one-dimensional nature of the IPGDS, additionally the 32-item scale revealed two factors (core grief and culturally specific symptoms). Psychometric analysis revealed strong internal consistency, concurrent validity and criterion validity. Limitations: The German-speaking and Chinese samples significantly differed in terms of several demographic variables including age, gender and type of loss. Conclusions: This preliminary validity study confirms that the IPGDS is a valid and reliable measure of the new ICD-11 PGD guidelines. This is the first scale of disordered grief to contain both core items and culturally specific supplementary items and aims to improve the clinical utility of the ICD-11 narrative approach.