Longitudinal trajectories of sleep duration in the general population.

BACKGROUND: Sleep duration has been associated with overall health status, health behaviours, and mortality. Little is known about habitual longitudinal patterns of sleep in the general population. Furthermore, evidence about whether sleep duration has declined in recent years is contradictory. DATA AND METHODS: The study was based on 8,673 adults aged 18 or older in 2002/2003 (cycle 5 of the National Population Health Survey) and used five …