Prefecture-Level Mean Elevation, Sleep Duration, and Depressive Symptoms Among Middle-Aged and Older Adults in China: A Cross-Sectional CHARLS Study

Background

Prefecture-level mean elevation, as an area-level proxy of residential altitude, has been associated with sleep disturbance and depressive symptoms, but it may also reflect broader regional differences in social conditions. The roles of sleep duration and regional context remain uncertain among long-term community residents.