[Changes on patterns of sleep duration: findings from China Health and Nutrition Survey in population in 9 provinces]

Objective: To understand the changes on patterns of sleep duration of the China Health and Nutrition Survey (CHNS) cohort in 9 provinces from 2004 to 2011. Methods: Four rounds of CHNS data were used. Urban/rural, age and gender specific insufficient sleeping rates and excessive sleeping rates were analyzed. Results: In 2004, 2006, 2009 and 2011, a total of 274, 281, 329 and 304 children aged 3-5 years; 874, 806, 768 and 742 children aged 6-12 years; 789, 529, 426 and 367 children aged 13-17 years; 9 568, 9 530, 9 942 and 9 609 adults aged ≥18 years were surveyed respectively. The lowest insufficient sleeping rate was 53.9% (200/371) in 3-17 years old children in rural area in 2006, the highest insufficient sleeping rate was 77.2% (44/57) in 3-5 years old children in urban area in 2004. The insufficient sleeping rate increased in rural 3-5 years old children from 2004 to 2011. For the adults aged ≥18 years, the insufficient sleeping rate ranged from 4.2% (82/1 954) in females aged 18-44 years in 2004 and 2009 to 20.8% (211/1 015) in urban residents aged > 60 years in 2011. The insufficient sleeping rate in age-groups 44-59 years and ≥60 years increased in both males and females and in both urban area and rural area from 2004 to 2011. The gender specific excessive sleeping rate in 3-17 years old children was very low in both urban area and rural area and no difference was found in different rounds of survey. The excessive sleeping rate in adults ranged from 18.4% (569/3 093) in urban population in 2011 to 32.5% (1 617/4 969) in females in 2004. The excessive sleeping rate of adult decreased from 2004 to 2011. Conclusion: We should pay attention to the fact that the insufficient sleeping rate in adolescents is high and in increase in rural 3-5 years old children and adults aged ≥45 years.