Objectives: To investigate the prevalence of centenarians who have preserved activities of daily living (ADLs) and good cognitive and psychosocial status in Japan.
Design: Census-based survey.
Setting: Cross-Sectional Investigation of Half of All Japanese Centenarians Study, 2000.
Participants: A nationwide census-based study was conducted of all of the male centenarians and a random sample of half of all the female centenarians who were included in the National Census of Japan. After excluding those who had died and whose addresses could not be identified, 1,907 centenarians (53.0%) participated in the present visitation interview survey.
Measurements: ADLs, cognitive status, and psychosocial status. Centenarians who have preserved ADLs and good cognitive and psychosocial status were defined as autonomous centenarians.
Results: Of the study subjects, 10.4% were judged to be autonomous centenarians. Multiple logistic regression analyses revealed that autonomy in centenarians was associated with better visual acuity, getting regular exercise, spontaneous awakening regularly in the morning, preserved masticatory ability, having no history of drinking, having no history of severe falls after the age of 95, more frequent intake of protein, living at home, and being male. It was also demonstrated that autonomous centenarians were not associated with appetite, vegetable or seaweed intake, smoking habits, auditory capacity, body mass index, or present illness.
Conclusion: These findings suggest that health practices play an important role in preserving ADLs and good cognitive and psychosocial status after reaching the age of 100 and should be useful for establishing an educational program for the ever-increasing "super elderly" population in Japan.