Factors associated with short and long sleep duration in older adults: Analysis of a national survey in Japan.

We need to be aware that older people with short sleep duration may have various physical symptoms. Moreover, as physical and mental problems, cognitive decline and unhealthy lifestyles are associated with long sleep duration, we also need to pay attention to the living conditions of those who complain of long sleep duration. The limitations of this study were that the variables were self-reported and sleep duration was not evaluated objectively. Geriatr Gerontol Int 2022; 22: 660-666.