Theoretical frameworks for measuring basic activities of daily living in individuals with dementia: a mixed-methods study

BACKGROUND: Accurate assessment of Basic Activities of Daily Living (BADL) is essential for dementia care and research. Existing instruments often lack a consolidated theoretical foundation, inadequately capture dementia-specific nature of BADL limitations, and overlook preserved competences, thereby compromising assessment comparability and reliability. AIM: To develop dementia-specific theoretical frameworks for BADL by synthesizing evidence from a systematic review of existing instruments and the lived experiences of family caregivers. METHOD: A mixed-methods approach was employed, integrating a systematic literature review with semi-structured interviews. The systematic literature review was completed following the Joanna Briggs Institute methodology. Database searches (i.e., CINAHL, MEDLINE, EMBASE, PsycINFO, PubMed, Web of Science) and manual searches were conducted. The final search was conducted in November 2024. Semi-structured face-to-face interviews were conducted with family caregivers purposively enrolled in Guangzhou, China, between December 2020 and November 2021. Thematic analysis was applied to each dataset separately, followed by a synthesis to integrate findings and develop conceptual models. RESULTS: Thirty BADL instruments were reviewed and twenty-three family caregivers were interviewed. After synthesizing the findings from both the literature review and qualitative interviews, six themes emerged: (1) dementia-specific BADL limitation phenotypes, (2) capacity-focused support, (3) cognitive impairments as primary drivers, (4) neuropsychiatric symptoms as exacerbating factors, (5) physical function decline as a compounding factor, and (6) environmental and interpersonal moderators. The synthesis resulted in two complementary frameworks: (i) an ICF-based multifactorial model illustrating the dynamic interplay among cognitive, physical, neuropsychiatric, and contextual factors shaping BADL in dementia; and (ii) a hierarchical pathway model delineating the progression of limitation phenotypes-namely, initiation, planning, organizational, and execution deficits-alongside escalating support needs, including prompts, item preparation, supervision, and physical assistance. This model also highlights preserved competences and the distinct role of resistive behaviors. CONCLUSION: This study provides integrated frameworks that conceptualize BADL in dementia as a dynamic outcome of interactions between individuals with dementia and contextual factors. The frameworks offer a theoretical basis for developing more sensitive, dementia-specific BADL assessment tools and for guiding personalized, supportive interventions.