Table 1.

Characteristics of researches included.

Study	country	Participants	Cohort size	Sex	Age (years)	Data acquisition	Screen device reported			Covariates	Literature quality evaluation score
							computer	TV	mobile device
Hakala 2006	Finland	adolescents	6003	Male = 2665 Female = 3338	14∼18	Self-report	✓	✓	✓	Age, sex, school success, timing of puberty, stress symptoms	8
Torsheim 2010	Denmark	adolescents from Nordic countries	31022	NM	11,13,15	Self-report	✓	✓		Country, age, socioeconomic status, depression, school stress, physical activity	7
Shan 2013	China	students	3016	Male = 1460 Female = 1556	15∼19	Self-report	✓		✓	Sex, grade, soreness after exercise, digital device use, sitting time after school and personal emotions	8
Brindova 2015	Slovak	students	8042	Male = 3,910 Female = 4,132	11∼15	Self-report	✓	✓		Age, sex	7
Rossi 2016	Finland	students	1637	Male = 772 Female = 865	14∼16	Self-report	✓			Age, sex, BMI, chronic diseases, smoking	8
Noll 2016	Brazil	students	1439	Male = 765 Female = 674	11∼16	Self-report	✓	✓		Age, sex	8
Silva 2017	Portugal	students	969	Male = 467 Female = 502	13∼19	Self-report	✓		✓	Age, sex, BMI, physical activity, sleep quality	7
Bento 2020	Brazil	students	1628	Male = 798 Female = 830	14∼18	Self-report	✓		✓	Sex, type/time of computer, daily use time/posture (mobile phone), daily use time (tablet), mental health problems	7
Joergensen 2021	Denmark	pre-adolescents	45,555	Male = 21,711 Female = 23,844	11∼12	Self-report	✓			Sex, age, family type, on parental education, household income, physical activity	7

NM = not mentioned.