[Investigation and analysis on correlative factors of sleeping time in 2k12 year-old children in Changsha].

Objective: To study the sleeping time and its correlative factors in 2k12 year-old children in Changsha.

Methods: A cluster sample with 3 756 children was randomly selected from Changsha, whose parents or care persons were interviewed with questionnaires about children's sleeping status from June 2006 to April 2007 by trained medical staff. One person was responsible for a questionnaire for one child.