Statistical analysis
Statistical analyses were performed using SPSS v.22 (IBM Corp., Armonk,
NY, USA). To investigate differences in sleep quality, insomnia, and
psychological symptoms between AD and healthy adults, the questionnaire
scores (PSQI, ISI, BDI-II, GAD-7, PSS-10) of the two groups (Atopic
Dermatitis, Control) were compared using the independent samples t-Test.
Cohen’s d was computed to provide an effect size estimate of the
comparisons between groups.
We estimated the influence of objective and subjective severity of AD on
sleep quality and insomnia by performing several univariable linear
regression analyses, with EASI and POEM scores as independent variables
and PSQI and ISI scores as dependent variables.
Similarly, we performed univariable linear regression analyses to test
if objective (EASI) and self-perceived (POEM) severity of AD
(independent variables) significantly predicted depression (BDI-II),
anxiety (GAD-7), and self-perceived stress (PSS-10; dependent
variables). The level of significance was set at p < 0.05, and
all analyses were two-tailed.