Instruments for measuring grief in bereaved adults: a protocol for a COSMIN-based systematic review.

introductionGrief associated with bereavement is a multidimensional psychological, physiological and behavioural response to the loss of loved ones. Bereaved individuals may experience physical distress, separation anxiety, intense yearning and cognitive confusion, with an increased risk of adverse physical and mental health outcomes, including death. Currently, various tools are used to measure grief in bereaved adults; however, these tools show significant differences in their cultural context and quality of development. Psychometric properties, including reliability, validity and responsiveness, etc., are essential for ensuring the scientific use of grief assessment tools and for evaluating the effectiveness of interventions. Previous reviews have lacked a standardised methodological framework for psychometric evaluation of grief instruments. Therefore, this study aims to identify and evaluate the psychometric properties of grief assessment instruments in bereaved adults in accordance with the Consensus-based Standards for the Selection of Health Measurement Instrument (COSMIN) methodology. METHODS AND ANALYSIS: This study will adhere to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocol 2015 checklist. A systematic search will be conducted across 7 English and 2 Chinese databases from their inception until 1 March 2025. Studies focusing on the psychometric properties of instruments for measuring grief in bereaved adults will be included. 2 reviewers will individually screen and extract the relevant literature. This systematic review will adhere to the COSMIN guidelines for instrument evaluations. A qualitative synthesis approach will be used to aggregate the psychometric properties of each instrument across studies. The COSMIN Risk of Bias Checklist will be employed to assess the risk of bias, while the COSMIN quality criteria will be applied to evaluate the methodological quality of the findings. The principle of taking the lowest rating will be used when summarising the quality of each psychometric property. The overall quality of evidence will then be appraised using a modified Grading of Recommendations Assessment, Development and Evaluation approach, which will inform recommendations for the evidence-based use of the instruments. ETHICS AND DISSEMINATION: This study is a meta-analysis of data from existing studies that do not involve direct interaction with human participants or the collection of patient-specific information. Consequently, review by an ethics committee was not applicable. The findings of this study will be published in a peer-reviewed journal and shared at relevant conventions. PROSPERO REGISTRATION NUMBER: CRD42024573767.