Pain in dementia: A systematic review of the measurement properties of observational assessment tools

We conducted a systematic review of the measurement properties and quality of evidence of observational pain assessment tools for older adults with dementia. Eligible studies were peer-reviewed, written in English, had a primary aim to psychometrically examine observational pain tools in samples of older adults with dementia, and reported results for at least one psychometric measurement property (e.g., reliability, structural validity, responsiveness). Medline, PsycINFO, the Cumulative Index of Nursing and Allied Health Literature (CINAHL), and Web of Science were systematically searched for all historical records to September 2025. The review was pre-registered in PROSPERO in February 2025, and adhered to the COnsensus based Standards for the selection of health status Measurement INstruments (COSMIN), and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting guidelines for COSMIN systematic reviews (i.e., PRISMA-COSMIN) to evaluate and report the methodological quality, psychometric results, and strength of evidence for each tool. This standardized framework also guided our recommendations of tools based on psychometric merit. Thirty observational pain tools were identified across 121 psychometric studies, and five tools met criteria for a strong recommendation. Certain measurement properties (i.e., construct validity, responsiveness) showed stronger results and higher-quality evidence across tools, while others (e.g., structural validity, content validity) were understudied and showed inconsistent and lower-quality evidence. We summarized methodological limitations in the pre-existing literature and provided research recommendations to help direct future scholarly work in this area.