Table 1.
Study characteristics of the 49 included studies in the systematic review
| n (%) | |
|---|---|
| Geographic location | |
| North America | 18 (37) |
| Europe | 23 (47) |
| Australia and New Zealand | 5 (10) |
| Several western countries included | 3 (6) |
| Age range | |
| 0–5 years | 11 (22) |
| 6–12 years | 13 (27) |
| 13–15 years | 23 (47) |
| 0–15 yearsa | 2 (4) |
| Study design | |
| RCT study | 3 (6) |
| Quasi-experimental study | 2 (4) |
| Prospective cohort study | 15 (31) |
| Cross-sectional study | 29 (59) |
| Electronic media devicesb | |
| Television | 18 (37) |
| Video game | 12 (25) |
| Mobile phone/smartphone | 13 (27) |
| Computer/internet | 14 (29) |
| Touchscreen/tablet | 3 (6) |
| Social media | 7 (14) |
| Total screen time | 43 (21) |
| Electronic media devices in the bedroom | 5 (10) |
| Media content (e.g., violent content) | 1 (2) |
| Sleep outcomec | |
| Delayed bedtime/sleep onset latency | 22 (45) |
| Poor sleep quality | 19 (29) |
| Short sleep duration | 36 (73) |
| Daytime tiredness | 15 (31) |
aWe have predefined three age group categories. If a study included data on ages overlapping the defined age categories, we used the mean age to allocate the study to an age category. A few studies (n = 2) included a large age span
bAs some articles examine several electronic media devices within the same study, this column does not add up to 100%
cAs some articles examine several sleep outcomes within the same study, this column does not add up to 100%