Table 2.
Results of fixed effects parameters for change in IUD symptoms and secondary outcomes
| Variable | Parameter | Estimate | SE | t value | P value | d |
|---|---|---|---|---|---|---|
| Primary outcome measures | ||||||
| IUD self-report (CIUS; n = 26) | Intercept | 22.395 | 1.573 | 14.24 | <0.001 | |
| Time | −0.664 | 0.119 | −5.59 | <0.001 | 1.004 | |
| IUD self-report (CSAS-SR; n = 54) | Intercept | 17.283 | 1.261 | 13.71 | <0.001 | |
| Time | −0.534 | 0.091 | −5.86 | <0.001 | 0.743 | |
| IUD parental report (CSAS-PR; n = 16) | Intercept | 29.240 | 2.280 | 12.82 | <0.001 | |
| Time | −0.514 | 0.159 | −3.24 | 0.002 | 0.961 | |
| Secondary outcome measures | ||||||
| Amount of time spent online (n = 54) | Intercept | 0.622 | 0.028 | 21.86 | <0.001 | |
| Time | −0.003 | 0.002 | −1.18 | 0.243 | 0.283 | |
| Psychopathology self-report (SDQ-SR; n = 26) | Intercept | 10.183 | 0.819 | 12.43 | <0.001 | |
| Time | −0.033 | 0.078 | −0.42 | 0.674 | 0.118 | |
| Psychopathology parental report (SDQ-PR; n = 50) | Intercept | 14.732 | 0.857 | 17.19 | <0.001 | |
| Time | −0.177 | 0.064 | −2.76 | 0.007 | 0.567 | |
| Depressive symptoms (DIKJ; n = 54) | Intercept | 3.709 | 0.143 | 25.90 | <0.001 | |
| Time | −0.186 | 0.043 | −4.29 | <0.001 | 0.489 | |
| Social anxiety (SIAS; n = 54) | Intercept | 4.714 | 0.235 | 20.04 | <0.001 | |
| Time | −0.177 | 0.063 | −2.81 | 0.006 | 0.302 | |
| Performance anxiety and school anxiety (PHOKI; n = 54) | Intercept | 5.686 | 0.584 | 9.73 | <0.001 | |
| Time | −0.112 | 0.043 | −2.62 | 0.010 | 0.297 | |
| Procrastination (APROF; n = 26) | Intercept | 3.069 | 0.198 | 15.48 | <0.001 | |
| Time | 0.022 | 0.022 | 1.00 | 0.322 | 0.022 | |
| Functional regulation (FEEL-KJ; n = 54) | Intercept | 126.576 | 3.442 | 36.78 | <0.001 | |
| Time | 0.299 | 0.351 | 0.85 | 0.396 | −0.211 | |
| Dysfunctional regulation (FEEL-KJ; n = 54) | Intercept | 74.441 | 2.223 | 33.48 | <0.001 | |
| Time | −0.167 | 0.221 | −0.759 | 0.450 | 0.097 | |
| Social behavior (SSL; n = 54) | Intercept | 58.210 | 1.162 | 50.09 | <0.001 | |
| Time | 0.155 | 0.111 | 1.40 | 0.164 | −0.222 | |
| Learning behavior (SSL; n = 26) | Intercept | 37.283 | 1.231 | 30.27 | <0.001 | |
| Time | −0.035 | 0.118 | −0.296 | 0.768 | −0.135 | |
| Self-efficacy (SWE; n = 54) | Intercept | 28.692 | 0.760 | 37.75 | <0.001 | |
| Time | 0.115 | 0.066 | 1.74 | 0.085 | −0.289 | |
Note: Intercept reflects pretest score, and time reflects linear change per month. Amount of Time Spent Online is presented in hours per day, the variable was log transformed. CIUS = Compulsive Internet Use Scale; CSAS-SR = Video Game Dependency Scale Self-Report; CSAS-PR = Video Game Dependency Scale Parental Report; SDQ-SR = Strengths and Difficulties Questionnaire Self-Report; SDQ-PR = Strengths and Difficulties Questionnaire Parental Report; DIKJ = German version of the Children's Depression Inventory; SIAS = Social Interaction Anxiety Scale; PHOKI = German revision of the Fear Survey Schedule for Children – Revised; APROF = German Questionnaire for Procrastination; FEEL-KJ = German Questionnaire for Assessment of Emotion Regulation in Children and Adolescents; SSL = German Student Assessment List for Social and Learning Behavior; SWE = German General Self-Efficacy Scale; SE = standard error; d = Cohen's d statistic.