Table 4.
Per-protocol (PP) linear mixed model analysis of group, time and interaction effects on individual and parental stress.
| Fixed effects | Individual stress |
Parental stress |
||||
|---|---|---|---|---|---|---|
| F | df | p | F | df | p | |
| Intercept | 1679.50 | 1;188 | <.001** | 721.73 | 1;158 | <.001** |
| Group | 2.19 | 2;94 | .118 | 0.77 | 2;79 | .468 |
| Time | 28.32 | 2;188 | <.001** | 24.52 | 2;158 | <.001** |
| Group × time | 4.44 | 4;188 | .002** | 1.05 | 4;158 | .386 |
| Random effects | Variance | Variance | ||||
| Intercept | 37.22 | 54.52 | ||||
| Residual | 12.31 | 18.87 | ||||
| Model fit indices | Marginal | Conditional | Marginal | Conditional | ||
| Pseudo-R2 | .07 | .74 | .04 | .82 | ||
| AIC | 1778 | 1600 | ||||
| BIC | 1818 | 1638 | ||||
Note. N = 97 participants (parental stress: 82), 291 observations (parental stress: 246). Sample sizes differ due to a technical error preventing some participants in the WLC group from submitting the parental stress questionnaire at T2. AIC: Akaike Information Criterion. BIC: Bayesian information criterion. Marginal Pseudo-R2 indicates the proportion of variance explained by the fixed factors only, whereas conditional Pseudo-R2 indicates the proportion of variance explained by the overall model. *p < .05, **p < .01.