Screen Time and Body Mass Index Among Children and Adolescents: A Systematic Review and Meta-Analysis

Background There is no summative quantitative study that report the difference in BMI in high screen user children and adolescents or give a difference in screen time in children and adolescents with obesity vs. children and adolescents without obesity. In the current meta-analysis we systematically summarized the association between obesity and screen time and meta-analyzed the results. Methods A systematic search from Scopus, PubMed and Embase electronic databases. Studies that evaluated the association between screen time and obesity up to June 2021. Results Results revealed that those at the highest screen time category had 0.7 kg/m2 higher BMI (WMD = 0.703; CI = 0.128, 1.278; P < 0.016; I2 = 95.8%). Moreover, children and adolescents with obesity had a mean value of 0.313 h higher screen time compared with children and adolescents without obesity (WMD: 0.313; OR = 0.219, 0.407; P < 0.001; I2 = 96%). The results of subgrouping showed that study quality, continent and sample size could reduce the heterogeneity values. No evidence of publication bias was reported according to visual asymmetry of funnel plots and the results of Begg’s and Egger’s tests. Conclusion For the first time, the current systematic review and meta-analysis revealed a positive association between screen time and obesity among children and adolescents. Due to the cross-sectional design of the included studies, causal inference is impossible, therefore, further studies in separate analysis of both genders are suggested to better elucidate gender-specific results. Systematic Review Registration [www.ClinicalTrials.gov], identifier [CRD4202123 3899].


Rationale
Describe the rationale for the review in the context of what is already known.Pages 3 and 4 Objectives Provide an explicit statement of questions being addressed with reference to participants, interventions, comparisons, outcomes, and study design (PICOS).

Protocol and registration
Indicate if a review protocol exists, if and where it can be accessed (e.g., Web address), and, if available, provide registration information including registration number.
Page 5; lines 1-3 Eligibility criteria Specify study characteristics (e.g., PICOS, length of follow-up) and report characteristics (e.g., years considered, language, publication status) used as criteria for eligibility, giving rationale.
Page 5; lines 4-13 Information sources Describe all information sources (e.g., databases with dates of coverage, contact with study authors to identify additional studies) in the search and date last searched.

Search
Present full electronic search strategy for at least one database, including any limits used, such that it could be repeated.

Study selection
Give numbers of studies screened, assessed for eligibility, and included in the review, with reasons for exclusions at each stage, ideally with a flow diagram.

Study characteristics
For each study, present characteristics for which data were extracted (e.g., study size, PICOS, follow-up period) and provide the citations.
Page 7; lines 18-26; Page 8; lines 1-14; Tables 1-3 Risk of bias within studies Present data on risk of bias of each study and, if available, any outcome level assessment (see item 12).Sup.Table 3 Results of individual studies For all outcomes considered (benefits or harms), present, for each study: (a) simple summary data for each intervention group (b) effect estimates and confidence intervals, ideally with a forest plot.

Synthesis of results
Present results of each meta-analysis done, including confidence intervals and measures of consistency.Figure 2   Sup.Table 3. Agency for Healthcare Research and Quality (AHRQ) checklist to assess quality of the cross-sectional studies

Hoffmann B [2]
Tsuchiya M Alghadir AH [5] Al-Agha AE [6] Stamatak is E [7] Hardy LL [8] Cheng L [9] Elizondo-MontemayorL [10] 1) Define the source of information (survey, record review) 2) List inclusion and exclusion criteria for exposed and unexposed subjects (cases and controls) or refer to previous publications 3) Indicate time period used for identifying patients 4) Indicate whether or not subjects were consecutive if not population-based 1) Define the source of information (survey, record review) 2) List inclusion and exclusion criteria for exposed and unexposed subjects (cases and controls) or refer to previous publications 3) Indicate time period used for identifying patients 2) List inclusion and exclusion criteria for exposed and unexposed subjects (cases and controls) or refer to previous publications 3) Indicate time period used for identifying patients 4) Indicate whether or not subjects were consecutive if not population-based

6 ) 9 ) 11 ) 1 .
) Indicate if evaluators of subjective components of study were masked to other aspects of the status of the participants Describe any assessments undertaken for quality assurance purposes (e.g., test/retest of primary outcome measurements) If applicable, explain how missing data were handled in the analysis Clarify what follow-up, if any, was expected and the percentage of patients for which incomplete data or follow-Begg's funnel plot (with pseudo 95% CIs) of the comparison of BMI between highest versus lowest screen time categories (A); the comparison of screen time (ST) between obese versus non-obese youth (B); odds of screen addiction among obese versus non obese youth (C).

Table 2 .
Describe sources of funding for the systematic review and other support (e.g., supply of data); role of funders for the systematic review.Search strategies and the number of records according to different electronic database and 3 Risk of bias across studies Present results of any assessment of risk of bias across studies (see Item 15).Sup. Figure 1 Page 8; lines 16-20 Additional analysis Give results of additional analyses, if done (e.g., sensitivity or subgroup analyses, meta-regression [see Item 16]).
) Indicate if evaluators of subjective components of study were masked to other aspects of the status of the participants