Mediating effects of rumination on insomnia in cancer survivors: Influences of cancer‐related fatigue, fear of recurrence, and psychological distress

Background While advancements in cancer treatments have improved survival rates, they also lead to adverse effects such as insomnia, which significantly impacts survivors' sleep quality. Objective This study explores the influence of cancer‐related fatigue (CRF), Fear of Cancer Recurrence (FCR), and psychological distress, with rumination serving as a mediating factor, on the insomnia experienced by cancer survivors. Methods The study involved 220 cancer survivors attending Shohada‐e‐Tajrish Hospital's oncology center in Tehran, Iran. Participants were selected through convenience sampling and completed several questionnaires: the Insomnia Severity Index, Fear of Cancer Recurrence Inventory, Cancer Fatigue Scale, Kessler Psychological Distress Scale, and Rumination Response Scale. Results The results showed that the tested model had a good fit, and the correlation matrix demonstrated significant positive correlations between CRF (0.46), FCR (0.15), psychological distress (0.55), and rumination (0.42) with insomnia in cancer survivors ( p < 0.05). Notably, CRF (B = 0.356, p < 0.001) and psychological distress (B = 0.339, p < 0.001) affect insomnia both directly and indirectly through mediation by rumination, while the impact of FCR on insomnia was indirectly significant (B = 0.73, p < 0.05). Conclusion The findings suggest that interventions focused on managing rumination could be potential targets to alleviate insomnia and improve the sleep quality of cancer survivors.