Screen time for adults aged 18 to 64 years

Why do we study screen time?

• Screen time refers to the time spent seated in front of screens (e.g., television, computers, or mobile devices) for activities that are not related to educational levels or work.  
• Studying screen time is important because it can be an important part of an individual’s sedentary behavior. Excessive screen use can impact physical health, mental well-being, and overall lifestyle habits, including sleep and physical activity.
• Understanding screen time helps to identify potential risks and develop strategies to promote healthier behaviors.

How do we do it?

• Screen time was examined using a self-report questionnaire investigating the following two aspects of screen use, separately for week and weekend days:
  • daily time spent sitting or lying down while watching films, videos, series, or playing video games during leisure time ;
  • daily time spent sitting or lying down using a computer, tablet, or smartphone during leisure time ;
• Respondents were asked to select between the following categories: ‘1 to 15 minutes per day’, ‘15 to 30 minutes per day’, ‘30 to 60 minutes per day’, ‘1 to 2 hours per day’, ‘2 to 3 hours per day’, ‘3 to 4 hours per day’, ‘4 to 5 hours per day’, ‘5 to 6 hours per day’, ‘6 to 7 hours per day’, ‘More than 7 hours per day’;
• For week and weekend days separately, the categories of the two questions were summed and recategorized as ‘Less than 2 hours per day’, ‘Between 2 – 4 hours per day’, ‘Between 4 – 8 hours per day’, ‘More than 8 hours per day’ ;
• To indicate high screen time, a cut-off point was established at four hours or more per day.
• Although questionnaires have many advantages, they also have limitations. It is difficult to accurately assess screen time because people often struggle to accurately evaluate their own screen time. In this case, screen time was measured using categories rather than precise durations. Additionally, screens can be used simultaneously, leading to overestimations of actual screen time (e.g., using a smartphone while watching a film). This issue, combined with factors such as forgetfulness and a desire to provide socially acceptable answers, can contribute to inaccuracies in reported screen time.