Associations between Functional Mobility, Physical Functioning, and Dementia Caregiving Time

Abstract

To identify early mobility disability in people with cognitive impairment and to provide objective outcome measures of exercise and rehabilitation interventions, sensitive, valid, and reliable measures are needed. Portable inertial sensor systems have demonstrated sensitivity to mobility changes in Parkinson’s disease, multiple sclerosis, and general populations of older adults. However, there has been no published information on whether inertial sensor-based measures are valid and reliable when administered with persons with dementia (PWDs). Additionally, even though the link between functional mobility and disability in activities of daily living (ADLs) has been supported in prior research, the association between (1) functional mobility in PWDs, (2) caregiver-reported PWD physical functioning, and (3) caregiver-reported dementia caregiving time spent in assisting ADLs remains unknown. To help bridge this gap, the purposes of this dissertation were (1) to examine the concurrent validity and test-retest reliability of a five-time sit-to-stand test (FTSTS) collected with an inertial sensor system in people with mild cognitive impairment and dementia, and (2) to investigate the associations between PWD functional mobility (measured by the FTSTS and additional FTSTS subtask parameters obtained by the inertial sensor system), caregiver-reported PWD physical functioning, and caregiver-reported dementia caregiving time spent in assisting ADLs. The overall results suggest that (1) FTSTS subtask parameters (i.e. total time, mean sit-to-stand duration, mean stand-to-sit duration, mean sit-to-stand lean angle, mean stand-to-sit lean angle) collected by the portable sensor system (coined as “iFTSTS” parameters in this dissertation) have good to excellent concurrent validity when compared to FTSTS parameters simultaneously collected by a laboratory-based human motion capture system in people with mild cognitive impairment and mild dementia; (2) iFTSTS parameters have fair to good test-retest reliability over a 1-month period in PWDs; (3) higher PWD functional mobility (as measured by the ability to complete the FTSTS, FTSTS total duration, iFTSTS total duration, iFTSTS mean sit-to-stand duration, and iFTSTS mean stand-to-sit duration) is associated with better caregiver-reported PWD physical functioning; (4) higher caregiver-reported PWD physical functioning is associated with shorter caregiver-reported caregiver time spent in assisting PWDs with ADLs; and (5) higher functional mobility (as measured by the ability to complete the FTSTS) is associated with shorter caregiver-reported dementia caregiving time spent in assisting PWDs with ADLs.