PROTOCOL: Psychometric properties of instruments for measuring elder abuse and neglect in community and institutional settings: A systematic review.

Screening of titles, abstracts, and full texts of the selected studies will be evaluated based on the preset inclusion criteria by two reviewers. Two reviewers will be assessing the quality appraisal of each study using the COSMIN Risk of Bias checklist and the overall quality of evidence of each psychometric property of the instrument against the updated criteria of good measurement properties. Any dispute between the two reviewers will be resolved through discussions or consensus with a third reviewer. The overall quality of the measurement instrument will be graded using a modified GRADE approach. Data extraction will be performed using the data extraction forms adapted from the COSMIN Guideline for Systematic Reviews of Outcome Measurement Instruments. The information includes the characteristic of included instruments (name, adaptation, language used, translation and country of origin), characteristics of the tested population, psychometric properties listed in the COSMIN criteria, including details on the instrument development, content validity, structural validity, internal consistency, cross-cultural validity/measurement invariance, reliability, measurement error, criterion validity, hypotheses testing for construct validity, responsiveness and interoperability. We will perform a meta-analysis to pool psychometric properties parameters (where possible) or summarise qualitatively.