The assessment of the perceived stress and the quality of life in the patients with myasthenia gravis: The mediating role of the psychological capital and social support.

Background: Stress has been known as a risk factor for the onset and modification of autoimmune disorders such as myasthenia gravis (MG). However, the patients can control their stress and improve their quality of life (QOL) using some factors such as psychological and social support. Psychological capital and social support play a key role in decreasing stress and improving QOL in the patients with MG. Therefore, the present study aimed to assess the mediator role of the psychological capital and social support in perceived stress and QOL of the patients with MG. Methods: In the present cross-sectional study, 203 patients with MG, including 138 women and 65 men, were selected from Iran Myasthenia Gravis Association and Shariati Hospital, Tehran City, Iran, using available sampling. The selected patients completed the Myasthenia Gravis Quality of Life questionnaire (MG-QOL), Luthans Psychological Capital Questionnaire (PCQ), Multidimensional Scale of Perceived Social Support (MSPSS), and Cohen Perceived Stress Scale (PSS-14). To assess the mediator role of the psychological capital and the perceived social support in the relationship with the perceived stress and QOL of the patients with MG, structural equation modeling (SEM) was used. Results: There was a significant negative relationship between the perceived stress and the variables of psychological capital (including hope, resilience, optimism, and self-efficacy), perceived social support dimensions (including support from important people, support from family, and support from friends), and QOL dimensions (including social activity and mental health) (P < 0.01). The results also showed that the perceived social support dimensions (including support from important people, support from family, and support from friends) and the variables of psychological capital (including hope, resilience, optimism, and self-efficacy) had a significant positive relationship with the QOL in patients with MG (P < 0.01). The indirect effect of perceived stress on the QOL through social support and psychological capital was 0.16 and 0.15, respectively, which was statistically significant (P < 0.05). Conclusion: The present study results show that a part of the shared variance between the conceptual circles of the perceived stress and QOL in patients with MG results from variability in the psychological capital and social support.