Existing validated tools for assessing intrinsic capacity and its components within a positive ageing framework: a scoping review and structured appraisal by the Multidisciplinary International Positive Ageing Group.

INTRODUCTION: Preserving intrinsic capacity (IC) is central to healthy ageing. However, no consensus exists regarding validated multidimensional instruments suitable for assessing IC across the adult lifespan. This scoping review identified instruments used to assess IC and to evaluate their scientific validity, clinical relevance and usability. METHODS: An updated literature search was conducted following the PRISMA-ScR guidelines in five databases for studies published between January 2022 and May 2025. This scoping review updates and expands upon a previously published comprehensive review. Nine experts independently evaluated all identified tools using predefined criteria: scientific validity, clinical relevance, usability in clinical practice, usability for self-assessment and suitability for adults aged <60 years. RESULTS: A total of 61 studies describing 61 distinct IC assessment instruments were included. All five IC domains were represented, although coverage across domains was uneven. Instruments assessing sensory capacity were scarce and generally received lower ratings than those targeting other domains. Only the Generalized Anxiety Disorder-7 and EUROQOL-5D achieved the maximum expert score. Importantly, very few instruments were considered appropriate for assessing IC in adults younger than 60 years, limiting their potential use for early identification of functional decline and preventive interventions. CONCLUSIONS: Current IC assessment instruments show substantial heterogeneity in content, validity and usability, with important gaps in the assessment of sensory capacity and younger adults. The gaps identified in this scoping review suggest that the development and validation of a comprehensive, multidimensional IC assessment tool may be warranted.