Statistical methods
depressive symptoms
REGRESSION
The descriptive statistics are presented as means with standard deviation (SD) or as counts with percentages. Group differences were evaluated using analysis of variances (ANOVA), and a chi-square test with post hoc comparisons using Sidak’s correction. The relationship between the depressive symptoms and diagnosis groups in regard to changes in HRQoL values was evaluated using a two-way analysis of covariance. Models included covariates for sex, age (biological), BMI, comorbidities (health and disease-related), education years and cohabiting (sociodemographic), when appropriate. A possible nonlinear relationship between BDI and adjusted change in HRQoL (15D) was assessed by using three-knot-restricted cubic spline regression models. Knot locations were based on Harrell’s recommended percentiles [