Insomnia and anxiety among COVID-19 patients in China: the chain mediating effect of psychological capital and self-esteem
Authors: Du Juan , Wu Chao , Zheng Wen-Kai , Cui Sheng-Nan , Li Ling , Liu Zhuo , Gao Li , Heng Chun-Ni , Lang Hong-Juan 
Published: April 2024

Abstract
Background
The outbreak of Corona Virus Disease (COVID-19) in 2019 has continued until now, posing a huge threat to the public’s physical and mental health, resulting in different degrees of mental health problems. As a vulnerable segment of the public, anxiety is one of the most common mental health problems among COVID-19 patients. Excessive anxiety aggravates the physical and psychological symptoms of COVID-19 patients, which is detrimental to their treatment and recovery, increases financial expenditure, affects family relations, and adds to the medical burden.

Objective
This study aimed to explore the role of psychological capital and self-esteem in the relationship between insomnia and anxiety, thereby shedding light on the mechanism of the effect of insomnia on anxiety in COVID-19 patients.

Methods
A cross-sectional study was conducted from April to May 2022 in Fangcang hospital in Shanghai, China. The self-administered questionnaires were distributed to 718 COVID-19 patients via cell phone using the Internet platform “Questionnaire Star”, which included Athens Insomnia Scale, Psychological Capital Questionnaire, Self-esteem Scale, Self-Rating Anxiety Scale, gender, age, marital status, education. Data analysis was performed using descriptive analysis, independent-samples t-test, one-way analysis of variance, Pearson correlation analysis, ordinary least-squares regression, and bootstrap method.

Results
Education background had significant impact on anxiety in COVID-19 patients (F = 7.70, P < 0.001). Insomnia, psychological capital, self-esteem and anxiety were significantly correlated, respectively (P < 0.001). And Regression analysis showed that insomnia had a direct negative predictive effect on psychological capital (β = -0.70, P < 0.001) and self-esteem (β = -0.13, P < 0.001). Psychological capital had a direct positive predictive effect on self-esteem (β = 0.12, P < 0.001). Insomnia had a direct positive predictive effect on anxiety (β = 0.61, P < 0.001). Both psychological capital and self-esteem had significant negative predictive effects on anxiety (β = -0.06, P < 0.05; β = -0.72, P < 0.001). The results showed that the mediating effect of psychological capital and self-esteem was significant, and the mediating effect value was 0.21. First, the indirect effect consisting of insomnia - psychological capital - anxiety was 0.04, showing that psychological capital had a significant mediating effect. Second, the indirect effect consisting of insomnia-self-esteem-anxiety had a value of 0.10, indicating that self-esteem had a significant mediating effect. Third, the indirect effect consisting of insomnia-psychological capital-self-esteem-anxiety had a value of 0.06, suggesting that psychological capital and self-esteem had a significant chain mediating effect between insomnia and anxiety.

Conclusions
Insomnia had a significant positive predictive effect on anxiety. Insomnia was first associated with a decrease in psychological capital, followed by a sequential decrease in self-esteem, which in turn was associated with increased anxiety symptoms in COVID-19 patients. Therefore, focusing on improving the psychological capital and self-esteem of patients can help alleviate the anxiety caused by insomnia in COVID-19 patients. It is recommended that patients and health care professionals increase the psychological capital and Self-esteem of COVID-19 patients through various methods to counter the effects of insomnia on anxiety.