4. Exposure to screens of digital media devices: The participants were asked about the presence and usage habits of digital media devices equipped with a screen (for example, TV, computer, tablet, and smartphone) and reported whether they had a TV, computer, tablet, and smartphone in their homes and bedrooms. They reported the duration of exposure time to digital screens of any digital media device for different time-periods of the day beginning in the morning until bedtime or sleep during weekdays and on weekends. We asked the participants to report on their exposure time to screens of digital devices the mean time in minutes of each separate time-period: early morning, before work or school, during work or study time, after work or study, until bedtime, and after bedtime. Digital media usage for all devices (TVs, computers, smartphones, and tablets) were computed for each 4-time periods of the day (sum-morning, Sum-day, sum-evening, and sum-night) reflecting the summation time in minutes to overall exposure time of digital media screens devices in each time segment of the day.