than that in the three higher trajectory groups until 5 years of follow-up but
decreased linearly thereafter. In contrast, the three higher trajectory groups exhibited
increases in monthly medical costs after the baseline survey; in particular, the third
trajectory group had a dramatic increase during the second half of follow-up, and
mean monthly medical costs were estimated at $619.6 after 12 years of follow-up.
Combined monthly medical and long-term care costs were slightly higher than
monthly medical costs alone. Interestingly, mean costs were highest in the third
trajectory group, which had the highest monthly medical and long-term care costs
after 8 years of follow-up (the combined costs were estimated at $884.8 after
12 years of follow-up).
In this 12-year longitudinal study of 1736 older adults, approximately 80% were
classified in the two higher trajectory groups, and they retained higher cognitive
function during the entire follow-up period. The cognitive function of the 16.8% of
participants in the third trajectory group remained relatively constant for the first few
years, gradually decreased after 3 years, and was consistent with dementia within
10 years of follow-up. Both the fourth trajectory (2.2%) and the low trajectory
(2.0%) groups had cognitive impairment at baseline and would likely have developed severe dementia had follow-up been longer. Thus, the lower cognitive trajectory might be associated with increased health-care costs. In fact, although the mean
monthly medical and long-term care costs were higher in the two lower trajectory
groups during the first 5 years of follow-up, they decreased linearly thereafter. The
period of decreasing health-care costs in these two groups after 5 years of follow-up
overlapped the period when their MMSE scores were below 20. The present third
trajectory group had the highest monthly medical and long-term care costs after
8 years of follow-up. Attempts to prevent dementia and reduce social security costs
for persons at high risk of dementia should target people with gradual cognitive
decline, especially those with an MMSE score lower than 23 points. These findings
demonstrated that individuals in the lower cognitive function trajectory groups had
higher dementia and mortality risks and their health-care costs were obviously high
in later life, which highlights importance of interventions that maintain or improve
cognitive function, even among older adults with low cognitive function.
6 Trajectories of Aging in Functional Capacity (Taniguchi
et al., 2018a)
The WHO Scientific Group on the Epidemiology of Ageing proposed that autonomy
or independence in functioning be used as a health index for elderly adults (World
Health Organization, 1984). Functional capacity has been recognized as a hierarchical framework, and Lawton (Lawton, 1972) defined and systemized seven
intercorrelated “sublevels” of competence—life maintenance, functional health,
perception and cognition, physical self-maintenance, instrumental self-maintenance,
effectance, and social role (Fig. 8).
A New Informatics: Trajectory Patterns in Health Indexes for Japanese Elders. . .
73
decreased linearly thereafter. In contrast, the three higher trajectory groups exhibited
increases in monthly medical costs after the baseline survey; in particular, the third
trajectory group had a dramatic increase during the second half of follow-up, and
mean monthly medical costs were estimated at $619.6 after 12 years of follow-up.
Combined monthly medical and long-term care costs were slightly higher than
monthly medical costs alone. Interestingly, mean costs were highest in the third
trajectory group, which had the highest monthly medical and long-term care costs
after 8 years of follow-up (the combined costs were estimated at $884.8 after
12 years of follow-up).
In this 12-year longitudinal study of 1736 older adults, approximately 80% were
classified in the two higher trajectory groups, and they retained higher cognitive
function during the entire follow-up period. The cognitive function of the 16.8% of
participants in the third trajectory group remained relatively constant for the first few
years, gradually decreased after 3 years, and was consistent with dementia within
10 years of follow-up. Both the fourth trajectory (2.2%) and the low trajectory
(2.0%) groups had cognitive impairment at baseline and would likely have developed severe dementia had follow-up been longer. Thus, the lower cognitive trajectory might be associated with increased health-care costs. In fact, although the mean
monthly medical and long-term care costs were higher in the two lower trajectory
groups during the first 5 years of follow-up, they decreased linearly thereafter. The
period of decreasing health-care costs in these two groups after 5 years of follow-up
overlapped the period when their MMSE scores were below 20. The present third
trajectory group had the highest monthly medical and long-term care costs after
8 years of follow-up. Attempts to prevent dementia and reduce social security costs
for persons at high risk of dementia should target people with gradual cognitive
decline, especially those with an MMSE score lower than 23 points. These findings
demonstrated that individuals in the lower cognitive function trajectory groups had
higher dementia and mortality risks and their health-care costs were obviously high
in later life, which highlights importance of interventions that maintain or improve
cognitive function, even among older adults with low cognitive function.
6 Trajectories of Aging in Functional Capacity (Taniguchi
et al., 2018a)
The WHO Scientific Group on the Epidemiology of Ageing proposed that autonomy
or independence in functioning be used as a health index for elderly adults (World
Health Organization, 1984). Functional capacity has been recognized as a hierarchical framework, and Lawton (Lawton, 1972) defined and systemized seven
intercorrelated “sublevels” of competence—life maintenance, functional health,
perception and cognition, physical self-maintenance, instrumental self-maintenance,
effectance, and social role (Fig. 8).
A New Informatics: Trajectory Patterns in Health Indexes for Japanese Elders. . .
73