Reproducibility of Assessment Tests Addressing Body Structure and Function and Activity in Older Adults With Dementia: A Systematic Review

Objective The purpose of this study was to analyze the relative and absolute reliability of assessment tests addressing body structure and function and activity in older adults with dementia. Methods Medline, Embase, Web of Science, The Cochrane Library, and Scielo were searched from inception until March 2021. Two independent reviewers performed the selection process based on titles, abstracts, and full text. Reliability studies of assessment tests in older adults with dementia were included. Methodological quality of the studies was evaluated using the COnsensus-based Standards for the selection of health Measurement INstruments Risk of Bias checklist. Relative reliability was analyzed using the intraclass correlation coefficient (ICC) interpreted based on Munro classification. Absolute reliability was analyzed using the minimal detectable change (MDC) and standard error of measurement. Results Fifteen studies involving a total of 560 older adults with dementia were included. Nineteen assessment tests were identified: 13 addressing body structure and function (muscle strength, postural balance, cardiorespiratory fitness) and 6 addressing activity (walking and mobility). Studies determined test-retest and interrater reliability. Fifteen studies evaluated relative reliability using the ICC, with values ranging from no or small correlation to very high correlations. Ten studies evaluated absolute reliability using the MDC or standard error of measurement or both. Conclusion Relative reliability of the assessment tests for body structure and function and activity was high to very high based on ICCs, demonstrating good reproducibility. Regarding absolute reliability, the analysis of the MDC values revealed the need for substantial change to determine that a real change had occurred. Future investigations should consider the type of dementia and standardization of verbal encouragement during the assessment. Impact This review identified the good reproducibility of assessment tests of body structure and function (muscle strength, postural balance, cardiorespiratory fitness) and activity (walking and mobility) domains in older adults with dementia. Clinically important values may differ when older adults with dementia of diverse etiologies are analyzed together and older adults specifically with Alzheimer disease. Identifying the type of dementia, analyzing types of dementia separately, and standardizing verbal commands during the execution of tests is of considerable clinical importance for this population of older adults.