Analysis of Biological Stress Indices in Patients with Gastrointestinal Cancer Based on Perceived Stress Mediated by Rumination using Structural Equation Modeling

Background: Considering the prevalence of this disease and the high mortality rate of gastric cancer in the country, it is necessary to investigate the causes and factors affecting this disease's incidence. Objective: This study aimed to analyze the structural equations of biological stress indices in patients with gastrointestinal cancer based on perceived stress mediated by rumination. Methods: This research was a descriptive-correlational study of structural equation modeling. The statistical population of this study included all patients with gastrointestinal cancer referred to Reza-Mashhad hospital and Avicenna Hospital in Tehran in 2020, of which 250 patients were selected by convenience sampling method. Data were collected using the perceived stress scale (PSS), Nolen and Hoxma rumination questionnaire, and biological stress indices. Data were analyzed using structural equation modeling and Pearson correlation statistical methods using SPSS.22 and AMOS.22 software. Results: The results showed that perceived stress (β=0.45, P0>0.001) directly affected rumination. Also, rumination (β=0.30, P=0.001) had a direct effect on biological stress indices. Rumination played a mediating role in the relationship between perceived stress and biological stress indices (RMSEA: 0.001; AGFI: 0.93). Conclusion: Considering that perceived stress and rumination are effective on biological stress of gastrointestinal patients, it is necessary for therapists to pay attention to modifying beliefs related to stress and rumination in the psychological health of gastrointestinal patients in order to improve the quality of life of patients.