Table 2. Examination of main effects of weekday screen time and sex, as well as the interaction between them, on outcome variables, controlling for SES and race/ethnicity.
| Standardized Beta | t statistic | p-value | Standard Error | Partial Correlation | |
|---|---|---|---|---|---|
| Depression | |||||
| Main effect of ST | 0.018 | 1.24 | .214 | .029 | .012 |
| Main effect of sex | 0.112 | 7.78 | < .001* | .166 | .075 |
| Main effect of R/E | -0.007 | -0.72 | .472 | .042 | -.01 |
| Main effect of SES | -0.141 | -14.01 | < .001* | .024 | -.13 |
| Interaction sex*ST | 0.028 | 1.48 | .139 | .038 | .014 |
| Anxiety | |||||
| Main effect of ST | -0.002 | -0.16 | .877 | .030 | -.001 |
| Main effect of sex | 0.036 | 2.42 | .016 | .176 | .023 |
| Main effect of R/E | -0.018 | -1.86 | .063 | .044 | -.018 |
| Main effect of SES | -0.045 | -4.36 | < .001* | .025 | -.042 |
| Interaction sex*ST | 0.031 | 1.66 | .097 | .040 | .016 |
| Internalizing | |||||
| Main effect of ST | 0.007 | 0.45 | .655 | .054 | .004 |
| Main effect of sex | 0.065 | 4.44 | < .001* | .310 | .043 |
| Main effect of R/E | -0.011 | -1.09 | .278 | .078 | -.010 |
| Main effect of SES | -0.077 | -7.49 | < .001* | .045 | -.072 |
| Interaction sex*ST | 0.036 | 1.91 | .056 | .071 | .018 |
| Externalizing | |||||
| Main effect of ST | 0.083 | 5.69 | < .001* | .051 | .055 |
| Main effect of sex | 0.069 | 4.73 | < .001* | .297 | .046 |
| Main effect of R/E | -0.014 | -1.41 | .159 | .075 | -.014 |
| Main effect of SES | -0.142 | -14.03 | < .001* | .043 | -.134 |
| Interaction sex*ST | 0.001 | 0.04 | .967 | .068 | .000 |
| Oppositional defiance | |||||
| Main effect of ST | 0.066 | 4.47 | < .001* | .027 | .043 |
| Main effect of sex | 0.077 | 5.31 | < .001* | .157 | .051 |
| Main effect of R/E | -0.021 | -2.19 | .029 | .040 | -.021 |
| Main effect of SES | -0.090 | -8.86 | < .001* | .023 | -.085 |
| Interaction sex*ST | 0.014 | 0.76 | .450 | .036 | .007 |
| Conduct disorder | |||||
| Main effect of ST | 0.096 | 6.65 | < .001* | .027 | .064 |
| Main effect of sex | 0.037 | 2.60 | .009 | .157 | .025 |
| Main effect of R/E | -0.006 | -0.62 | .539 | .040 | -.006 |
| Main effect of SES | -0.165 | -16.43 | < .001* | .023 | -.157 |
| Interaction sex*ST | 0.008 | 0.43 | .664 | .036 | .004 |
| Attention problems | |||||
| Main effect of ST | 0.074 | 5.07 | < .001* | .031 | .049 |
| Main effect of sex | 0.044 | 3.02 | .003* | .178 | .029 |
| Main effect of R/E | 0.011 | 1.12 | .261 | .045 | .011 |
| Main effect of SES | -0.095 | -9.36 | < .001* | .026 | -.090 |
| Interaction sex*ST | 0.013 | 0.71 | .480 | .041 | .007 |
| ADHD | |||||
| Main effect of ST | 0.088 | 6.04 | < .001* | .028 | .058 |
| Main effect of sex | 0.056 | 3.85 | < .001* | .163 | .037 |
| Main effect of R/E | 0.010 | 1.02 | .310 | .041 | .010 |
| Main effect of SES | -0.089 | -8.80 | < .001* | .024 | -.085 |
| Interaction sex*ST | 0.022 | 1.15 | .250 | .037 | .011 |
| Academic performance | |||||
| Main effect of ST | -0.107 | -7.37 | < .001* | .004 | -.074 |
| Main effect of sex | -0.083 | -5.69 | < .001* | .023 | -.057 |
| Main effect of R/E | -0.041 | -4.24 | < .001* | .006 | -.043 |
| Main effect of SES | 0.253 | 25.04 | < .001* | .003 | .244 |
| Interaction sex*ST | -0.010 | -0.54 | .593 | .005 | -.005 |
| Sleep quantity | |||||
| Main effect of ST | -0.149 | -10.69 | < .001* | .004 | -.103 |
| Main effect of sex | 0.011 | 0.80 | .426 | .022 | .007 |
| Main effect of R/E | -0.065 | -7.03 | < .001* | .006 | -.068 |
| Main effect of SES | 0.246 | 25.53 | < .001* | .003 | .239 |
| Interaction sex*ST | -0.018 | -1.00 | .316 | .005 | -.009 |
| Sleep quality | |||||
| Main effect of ST | 0.054 | 3.70 | < .001* | .041 | .036 |
| Main effect of sex | 0.008 | 0.58 | .565 | .236 | .006 |
| Main effect of R/E | 0.012 | 1.19 | .235 | .060 | .011 |
| Main effect of SES | -0.099 | -9.74 | < .001* | .034 | -.094 |
| Interaction sex*ST | 0.031 | 1.66 | .096 | .054 | .016 |
| Num. of close m. friends | |||||
| Main effect of ST | 0.029 | 2.06 | .039 | .026 | .020 |
| Main effect of sex | 0.247 | 17.60 | < .001* | .150 | .168 |
| Main effect of R/E | -0.013 | -1.34 | .182 | .038 | -.013 |
| Main effect of SES | 0.012 | 1.26 | .209 | .022 | .012 |
| Interaction sex*ST | 0.077 | 4.26 | < .001* | .034 | .041 |
| Num. of close f. friends | |||||
| Main effect of ST | 0.067 | 4.67 | < .001* | .031 | .045 |
| Main effect of sex | -0.285 | -20.15 | < .001* | .179 | -.191 |
| Main effect of R/E | -0.017 | -1.79 | .074 | .045 | -.017 |
| Main effect of SES | -0.014 | -1.376 | .169 | .026 | -.013 |
| Interaction sex*ST | 0.001 | 0.08 | .934 | .041 | .001 |
Note: Starred regressions are significant at Bonferroni corrected alpha .004. ST = weekday screen time in hours. R/E = race/ethnicity.