Four out of every 10 children have had sleep deprivation.

The reason for the lack of sleep was that the first place was 'school and tutoring', the second place was self-study at night, and the third place was home study.

According to the Ministry of Health and Welfare's 2018 Children's Comprehensive Survey, 38% of 2,510 children between the ages of 9 and 17 reported that they lack sleep.

In particular, 49.0%, half of those aged 12-17, complained of lack of sleep.

The average sleeping time for children aged 9-17 was 8.3 hours during the school year and 9.5 hours during vacation.

Sleep time varies with age.

During the 9-11 year-old semester, the average sleep time was 9.2 hours, but the average 12-17 year was 7.8 hours, less than 8 hours.

During the vacation, the average sleeping time was 10.1 hours for 9 ~ 11 years old, and 9.2 hours for 12 ~ 17 years old.

The most common reason for lack of sleep was because of private academy and tutoring.

The night self-study followed by home learning 13.0% and games 12.9%.

Compared to children in general households, respondents were more likely to have a lack of sleep due to games, chat and text messages, access to Internet adult sites, watching dramas and listening to music.

The higher the income, the higher the complaints of lack of sleep due to school and tutoring. The lower the income, the higher the percentage of games, self-study at night, watching dramas, and listening to music.

The survey was conducted by the Korea Institute for Health and Social Affairs from January 7 to February 28 this year, targeting households under 18 years of age nationwide, with a total of 439 respondents.