The purpose of the present study was to investigate the baseline characteristics related to the participation status in a longitudinal epidemiological study for the elderly. Nine hundred twenty-six self-supporting older adults lived in a local city located southwest in Japan were classified into the following 3 groups; non-participants (NP, n=170), participants for the baseline measurements (PB, n=278), and participants for both the baseline and follow-up measurements after two-years (PBF, n=478). The basic attributes including socioeconomic status, depressive symptoms, cognitive function, sleep quality, fitness, objectively- measured physical activity, habitual behavior, psychosocial characteristics and functional problems in daily life were assessed. Regarding the NP group, data were collected by questionnaire or home visits. According to the results of a multinomial logistic regression analysis adjusted for age, sex and years of education, significant odds ratios which indicate a poor status in most of the assessment items were observed in both the NP and PB groups in comparison to the PBF group. We concluded that sex (female), a higher age, fewer years of education, a cognitive function decline, depressive symptoms, a low fitness level, physical activity and daily living function, and poor psychosocial backgrounds were related to the non-participation and dropouts. These results should be considered in a longitudinal data analysis of the present study, as well as in the design setting of epidemiological studies dealing with physical activity indexes and care risk factors. Furthermore, these findings are also considered to be useful as basic data for such care prevention activities in the community.

Although multiple disability prevention efforts and interventions for older adults have been implemented in the community, only a limited number of studies have verified whether these efforts have actually reduced the occurrence of disability or frailty. This paper reviewed evidence on the effects of community-based interventions for disability prevention on risks of disability and frailty at both the individual and population levels. Consequently, first, participation in exercise or nutrition programs based on high-risk strategies significantly reduced the risk of disability occurrence and suppressed medical and care costs for frail older adults, compared with nonparticipants. However, the participation rate for elderly populations in such programs was extremely low. Second, the creation of self-management programs based on population strategies, such as exercise groups or community salons, significantly reduced the participant’s risk for disability and frailty. The number of such “gathering places” and the participation rate in the elderly population progressively increased, suggesting it may contribute to disability prevention not only at the individual level, but also at the population level. However, previous studies have required long terms (4–5 years) to confirm significant reduction in an individual’s risk for disability and frailty. Finally, although previous studies that verified the effects of disability or frailty prevention at the population level have been extremely limited, one study demonstrated it is possible to reduce the rate of disability at the population level. Further studies are needed to verify the effects of various community-based disability prevention efforts on individual- and population-level disability and frailty for older adults.