This study has a number of important findings. Firstly, people with depression reported significantly poorer HRQoL than the age-matched general population. Secondly, Tele-SSM improved the HRQoL of people with depression, but this remained lower than the age-matched general population, except for the EQ-VAS score. Thirdly, depression was associated with lower HRQoL while controlling for stress, anxiety symptoms, and sociodemographic characteristics.
Our findings indicated that people with depression had significant impairment in HRQoL in comparison with the age-matched general population. Our result is consistent with previous studies that people with depression were significantly more likely to have difficulties in usual activities, pain/discomfort, and anxiety/depression dimensions (Günther et al., 2008; Sapin et al., 2004). The current study found that mean EQ-VAS and utility scores of people with depression in pre-intervention were significantly lower than age-matched peers in the general population. Regarding utility score, our result is consistent with previous research that people with depressive disorder reported lower utility scores than the general population (0.73 vs 0.84, respectively) (Saarni et al., 2006).
After completing the Tele-SSM intervention, participants showed great improvement in almost all dimensions, with a large effect size for EQ-VAS score and a medium effect size for the utility score. Our result is similar to the finding found in a meta-analysis, which reported that cognitive behavioral therapy (CBT), one of the main foundations of Tele-SSM intervention, had a moderate size effect (Hedges’ g = 0.63) in improving HRQoL for adults with depression (Hofmann et al., 2017). Moreover, the effect sizes of this intervention are greater than the effect sizes of a self-management program for people with depression which is a group-intervention grounded in social learning theory (a medium effect size for EQ-VAS and a small effect size for utility score) (Turner et al., 2015). Compared to age-matched in the general population, there was no significant difference in EQ-VAS score between participants after completing the intervention and the general population.
Despite being improved after participating in the intervention, the proportions of problems in usual activities, pain/discomfort, and anxiety/depression dimensions were significantly higher as well as utility scores were still significantly lower in comparison to the age-matched general population. As demonstrated in previous studies (Angermeyer et al., 2002; Hansson, 2002; IsHak et al., 2015), our findings extend these findings in that we also found a clear and consistent pattern as people with depression who had improvement at the end of intervention with better total health status still have a substantially lower HRQoL compared to the general population.
We found an intercorrelation between depression, stress, and anxiety scores both at baseline and at the end of the intervention suggesting the comorbidities between depression and anxiety. The comorbidity between depression and anxiety was proven in a meta-analysis of longitudinal studies (Jacobson & Newman, 2017). The relationship between stress and anxiety/depression is bidirectional (Daviu et al., 2019; Park et al., 2019). Stress and depression are associated with epigenetic changes in genes related to resilience and susceptibility to stress, including stress-response genes (Park et al., 2019). Stress could produce anxiety and anxiety can trigger another cycle of stress, while stress is also a major contributor to depression (Bystritsky & Kronemyer, 2014). The association of depression and HRQoL is consistent with previous studies (Daly et al., 2010; IsHak et al., 2013; Saragoussi et al., 2018; Gao et al., 2019; Rapaport et al., 2005). To explain the impact of depression on HRQoL, a research found that depressive symptoms are directly associated or indirectly associated with HRQoL through the mediation of impaired function (Zhou et al., 2023).
Regarding the association between stress, anxiety, and HRQoL, we found that stress and anxiety were not associated with HRQoL controlling for depression symptoms. Our finding is consistent with the findings from another research which found that the association between anxiety and HRQoL disappeared when depression was included in the regression model (Gao et al., 2019). However, this finding is different from the finding from the study of Brenes with 919 participants, the regression analysis found that both depression and anxiety were significantly related to lower HRQoL (Brenes, 2007). While the impact of anxiety on HRQoL still needs further investigation, the impact of depression on HRQoL seems concrete.
Limitations
Firstly, this was neither a randomized control trial nor case-control study. Without a control group, the study results should be interpreted with caution as there might be other elements affecting the difference between pre-post intervention. Secondly, the study has a small sample size, with the majority being female (90%) and younger than 50 years old (95%). The main reason causing small sample size of male could be a gender norms that men should be strong, should not show weakness could negatively affect the disclosure of mental health issues and mental health-seeking behaviors among men of mental health and/or depression among the Vietnamese population (Vuong et al., 2011). Reasons to explain the small number of 50 + years old participants could be their difficulties in using the technology. As a result, these challenges could limit the generalizability of our study for Vietnamese adults with depression.