Association of Trajectories of Higher-Level Functional Capacity with Mortality and Medical and Long-Term Care Costs Among Community-Dwelling Older Japanese

Abstract Background Higher-level functional capacity is crucial component for independent living in later life. We used repeated-measures analysis to identify aging trajectories in higher-level functional capacity. We then determined whether these trajectories were associated with all-cause mortality and examined differences in medical and long-term care costs between trajectories among community-dwelling older Japanese. Methods 2,675 adults aged 65–90 years participated in annual geriatric health assessments and biennial health monitoring surveys during the period from October 2001 through August 2011. The average number of follow-up assessments was 4.0, and the total number of observations was 10,609. Higher-level functional capacity, which correspond to the fourth and fifth sublevels of Lawton’s hierarchical model, was assessed with the Tokyo Metropolitan Institute of Gerontology-Index of Competence (TMIG-IC). Results We identified four distinct trajectory patterns (high-stable, late-onset decreasing, early-onset decreasing, and low-decreasing) on the TMIG-IC through age 65–90 years. As compared with the high-stable trajectory group, participants in the late-onset decreasing, early-onset decreasing, and low-decreasing TMIG-IC trajectory groups had adjusted hazard ratios for mortality of 1.22 (95% confidence interval: 1.01–1.47), 1.90 (1.53–2.36), and 2.87 (2.14–3.84), respectively. Participants with high-stable and late-onset decreasing higher-level functional capacity trajectories had lower mean monthly medical costs and long-term care costs. In contrast, mean total costs were higher for those with low-decreasing trajectories, after excluding the large increase in such costs at the end of life. Conclusions People with a low-decreasing aging trajectory in higher-level functional capacity had higher risks of death and had high monthly total costs.