Data analysis
COVID-19-related stress, AD
SECONDARY
All statistical analyses were performed using SPSS 28 [Differences in sample characteristics between the participating and non-participating families and between the AD and No AD group were calculated using In line with our first aim, we compared the caregiver- and child-rated COVID-19-related stress levels of the AD group with those of the No AD group, and the caregiver- and child-rated COVID-19-related stress levels of the subsamples with adoptive or biological caregivers with those of the subsamples from out-of-home care, based on child and caregiver report. The primary outcome was caregiver- and child-rated COVID-19-related stress on the scale level and the secondary outcome was caregiver- and child-rated COVID-19-related stress on the item level. Differences in COVID-19-related stress between two groups were calculated using Mann–Whitney In line with our second aim, we calculated the proportion of families describing improvements (− 2 or − 1 on the item level; − 2.00 to − 0.50 on the scale level) and deteriorations (0.50 or 2 on the item level; 0.05–2 on the scale level) on treatment-related items and subscales according to caregiver report.In line with our third aim, the analysis of risk and protective factors of COVID-19-related stress, we used the child-rated total stress scale and the internal subscale of the caregiver-rated total stress scale as criterion in children with and without AD. Sociodemographic variables, child and caregiver characteristics, and perceived changes in external conditions were used as predictors. We developed the models for the AD group and the No AD group separately to be able to depict risk and protective factors in a more detailed way for each group. First, we calculated Pearson correlation coefficients for continuous variables and point-biserial correlation for dichotomous variables. Risk and protective factors were only included if the correlations with the respective criterion were significant (