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 gastrointestinal cancer and its high mortality in Iran, it is necessary to investigate the causes and factors affecting the incidence of this disease. Objective: This study aimed to analyze biological stress indices in patients with gastrointestinal cancer based on perceived stress mediated by rumination using structural equation modeling. Materials and Methods: This study was conducted in the form of a descriptive correlational design based on structural equation modeling. The statistical population of this study (n=250) included all patients with gastrointestinal cancer referred to Reza-Mashhad hospital and Avicenna Hospital, Tehran, in 2020, and selected by convenience sampling method. The instruments used to collect the necessary data were the Perceived Stress Scale, Ruminative Responses Scale, and biological stress indices. The gathered data were analyzed in SPSS software (version 22) and AMOS software (version 22) using structural equation modeling and Pearson correlation statistical methods. Results: The results showed that perceived stress directly affected rumination (β=0.45, P-value 0.001). Moreover, rumination had a direct effect on biological stress indices (β=0.30, P-value=0.001). 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 were effective on biological stress of gastrointestinal patients, therapists must pay attention to modifying beliefs related to stress and rumination in the psychological health of gastrointestinal patients to improve the quality of life of such patients.