Status and risk factors of screen time among middle school students in Shanghai.

[Objective]To understand the status of screen time among middle school students and to determine the risk factors of screen time among middle school students in Shanghai.[Methods]A total of 2 549 middle school students aged 9 to 16 years and their parents were recruited by a cluster sampling strategy in Shanghai in December,2010.A structured questionnaire was used to collect information on screen time and related risk factors.Proportion of screen time per day and the mean values of screen time were presented.An ordinal logistic regression models was developed to determine the contribution of each risk factor to screen time. [Results]The average screen time was 2.83 h/d during a week before the investigation among selected middle school students and the screen time at weekend was 2.06 times to school day.Not in senior grade,boy,TV set in bedroom,no TV time restriction,owned a computer,high level of trait anxiety,frequently eating snacks when watching TV and using computer,mother's home screen time in more than 2 h and no recognition on impact of screen time to health were the risk factors of screen time.[Conclusion]TV, computer,mobile phone and internet are important in students' life.Long screen time is one of potential risk factors of middle school students health.The screen time could be modified by multi-levels factors in social,family and individual realms.