2.3. Statistical Analysis
depression
ANOVA and chi-square tests were employed to examine the difference of baseline characteristics by alcohol use risk (Low vs. Hazardous). Continuous variables were described as means and standard deviations while categorical variables were presented as frequency and percentages.To investigate the mediation effect of changes in depression symptoms (measured at T2 compared to T1) on the relationship between changes in HRQoL (measured at T2 compared to T1) and alcohol use at T2, two simple mediation models were created using the mediation package in R (bruceR::PROCESS function, version 0.8.8) [Mediation analysis. Multiple mediation models were conducted to investigate the impact of change in depression symptoms on the relationship between HRQoL and alcohol consumption, controlling for demographic and clinical variables. The mediation package in R software was used to estimate the coefficients of the total, indirect, and direct effects, and the bias-corrected bootstrap method was employed to calculate 95% confidence intervals for the coefficients. To investigate the mediation effects of change in depression on the relationship between HRQoL and alcohol consumption, we calculated the proportion of mediation (PM, %) using the indirect effect divided by the total effect. The mediation process is illustrated in 