*3.1. Reliability*

In this study, we used well-established measures with appropriate psychometric properties (Table 3).


**Table 3.** Reliability evidence of the instruments used (*n* = 113).

Notes: α = Cronbach's alpha; *CR* = composite reliability, *AVE* = average variance extracted; Ω = McDonald's omega index.

### *3.2. E*ff*ects of the Programme*

The pre-test MANOVA results did not reveal statistically significant differences between the groups prior to the intervention, Wilks' Lambda, Λ = 0.571, *F* (5, 108) = 0.739, *p* = 0.333, with a small effect size (η*2* = 0.062, *r* = 0.11).

The ANOVA using the pre-test scores (Table 4) revealed no statistically significant differences in any of the dependent variables before the programme began, except for a significantly higher score for trait emotional intelligence in the experimental group compared with the control group. The size of the effect was low for trait emotional intelligence (μ<sup>2</sup> = 0.009). Applying Bonferroni correction showed no significant differences in any of the variables.

Results from the pre-test–post-test MANCOVA revealed significant differences between the two conditions, Wilks' Lambda, Λ = 0.899, *F* (5, 108) = 5.295, *p* = 0.003, with an average effect size (η*2* = 0.267, *r* = 0.32).

Next, we performed ANCOVA for the dependent variables using the post-test scores. To assess the magnitude of these differences, the effect size for each variable was calculated by partial eta-squared (Table 4).

### 3.2.1. Effects on Subjective Well-Being

There was no significant improvement in post-test health-related quality of life in the experimental group (Table 4). The experimental group did not show a significant increase in positive affect scores after testing. We confirmed a significant decrease in post-test negative affect scores in the experimental group (Table 4), with a medium effect size (μ<sup>2</sup> = 0.123; partial eta-squared).

### 3.2.2. Effects on Trait Emotional Intelligence

The analysis revealed significant improvements in trait emotional intelligence in the experimental group after the programme, with a medium effect size (μ<sup>2</sup> = 0.241) (Table 4).

### 3.2.3. Effects on Social Anxiety

There were no significant differences between the experimental and the control groups in SAS-T scores (Table 4).

**Table 4.** Mean, standard deviation, analysis of variance, analysis of covariance and effect size for differences in means (partial eta-squared) as a function of the experimental and control groups at pre-test and post-test.


Note: HRQL = health-related quality of life; PA = positive affect; NA = negative affect; TEI = trait emotional intelligence; SAS-T = Total Social Anxiety Scale; SD = standard deviation.
