TABLE 4

Effect Sizes (95% Confidence Limits) and Between-Group Tests of Heterogeneity (Q), Assessment of the Amount of Variability Caused by Random Error (I2), and Tests of Moderators for Studies Included in the Meta-analysis

VariableNo. of StudiesSMD (Random-Effects Model)Heterogeneity Within SubgroupsBetween-Groups χ2 Test (Q) of Moderators
Within-Groups χ2 Test (Q)I2
Point Estimate95% CLsEstimate, %95% CLs
LowerUpperLower, %Upper, %
Subgroup
    All studies included29
    Time point of data collectiona
        During intervention5−1.904−3.041−0.76713a69.2821.2588.02
        After intervention27−0.148−0.224−0.07150a47.7918.2166.67
    Studies with postintervention data27
    Type of data
        Adjusted4−0.243−0.401−0.0857a57.880.0086.00
        Raw23−0.112−0.189−0.0353231.650.0058.912.123
    Comparisons
        Before vs after the intervention5−1.349−2.601−0.09718a77.5245.7490.69
        Treatment vs control16−0.101−0.157−0.044120.000.0048.68
        Treatment vs controladjusted data4−0.243−0.401−0.085757.880.0086.00
        Treatment 1 vs treatment 22−0.032−0.8570.222127.240.0071.796.985
    Outcome
        Television only17−0.108−0.171−0.045160.000.000.00
        Total screen time10−0.211−0.369−0.05431a70.9744.6084.791.436
    Where study was found
        Literature search23−0.156−0.238−0.07445a51.1121.0969.71
        Reference list of another article3−0.17−0.5790.24333.330.0077.982.608
        Personal files10.148−0.2130.50900.00
    Publication type
        Journal article24−0.135−0.209−0.06241a48.7816.0268.76
    Thesis/dissertation3−0.968−2.2040.26910a80.0036.7693.681.734
    Age group
        <5 y2−0.105−0.4830.273250.000.0087.15
        5–11 y18−0.125−0.241−0.00828b39.290.0065.41
        12–18 y6−0.176−0.304−0.04918a72.2235.8687.970.501
        Not provided1−0.192−0.4490.0640
    Nonwhite
        >50%4−0.091−0.2110.02930.000.000.00
        ≤50%9−0.256−0.386−0.1261338.460.0071.68
        Unclear14−0.098−0.1990.00423b43.480.0069.824.345
    Male
        Unclear2−0.002−0.5870.584250.000.0087.15
        >50%9−0.225−0.423−0.02723a65.2229.1582.92
        ≤50%16−0.105−0.162−0.047150.000.000.001.454
    Country
        United States19−0.189−0.294−0.08437a51.3517.7071.24
        Non–United States8−0.074−0.1530.00470.000.000.002.956
    Overweight
        Not specified11−0.212−0.363−0.0619b47.370.0073.78
        >50%40.002−0.2680.27230.000.000.00
        ≤50%12−0.129−0.229−0.02927a59.2623.0278.441.963
    High-risk sample
        No19−0.142−0.213−0.07132b43.753.3667.26
        Yes8−0.269−0.6650.12620a65.0025.4083.580.039
    Television-control device
        No19−0.124−0.199−0.04934a47.069.6168.99
        Yes8−0.3−0.725−0.03515b53.330.0078.992.021
    Theory based
        No11−0.156−0.3490.0371637.500.0069.26
        Yes16−0.145−0.231−0.05935a57.1425.1975.450.01
    Setting of intervention
        School13−0.15−0.239−0.06126a53.8513.5675.36
        Home6−0.933−1.9330.06716a68.7526.2986.75
        Other (includes unclear)8−0.109−0.195−0.02470.000.000.002.891
    Interventionist
        Researcher4−0.384−1.1210.35412a75.0030.6490.99
        Other (includes unclear)23−0.138−0.21−0.06639b43.407.2765.460.421
    Screen time is the primary outcome
        Yes14−0.134−0.267024b45.830.0070.95
        No13−0.156−0.252−0.0625b52.009.6774.490.071
    Used valid data collection tool
        No9−0.165−0.3930.06421a61.9021.3281.56
        Yes18−0.151−0.23−0.07330b43.331.1767.510.011
    Source of the data
        Document20−0.2−0.306−0.09538a50.0016.2770.14
        Document and/or authors7−0.08−0.154−0.00660.000.000.003.378
    Random allocation to groups
        No6−0.464−0.9740.04718a72.2235.8687.97
        Yes21−0.142−0.213−0.07133b39.390.0064.051.496
    No. of study groups
        15−1.349−2.601−0.09718a77.7846.4890.77
        222−0.146−0.213−0.07933b36.360.0061.973.54
  • Three studies91,97,110 provided data during and after the intervention and are included in the calculation of the effect-size estimates both during and after the intervention.

  • a P ≤ .01.

  • b P ≤ .05.