Trajectories of physical functioning among US adults with cognitive impairment.

BACKGROUND: physical functioning impairment is common among persons with cognitive impairment, but little is known about physical functioning trajectories across the US population or how trajectories may differ among persons with dementia and mild cognitive impairment (MCI). OBJECTIVE: to examine trajectories of physical functioning among persons with MCI and dementia in the USA. DESIGN: we used data from the National Health and Aging Trends study (NHATS) 2011-18. Physical functioning was assessed using the NHATS Expanded Short Physical Performance Battery. PARTICIPANTS: the 661 individuals with MCI and 980 individuals with dementia were included in this study. METHODS: we applied group-based trajectory models to identify latent groups and estimate their trajectories. Multinomial logistic regressions were applied to examine relationships between sociodemographic and health characteristics and trajectory group memberships. RESULTS: both MCI- and dementia-specific trajectories differed at baseline levels and declined at varying rates across groups. Approximately, 78.43% of persons with MCI were in trajectories with a moderate rate of decline, with only 9.75% in a trajectory with good physical function and 11.82% with poor physical function without as much change over time. Among persons with dementia, approximately 81.4% experienced moderate or fast declines, and 18.52% with virtually no functional ability remained at this same low level. Worse physical functioning trajectories were found among persons who were females, Blacks, with at least four comorbidities, and among persons who had a low socioeconomic status. CONCLUSIONS: persons with both dementia and MCI experienced steady declines in physical functioning. Socioeconomically disadvantaged groups have worse physical functioning trajectories.