Insomnia in Cancer - Associations and Implications

Background: Insomnia is a common condition in cancer patients. In spite of the high prevalence its associations have not been well studied. Existing data suggests that insomnia is related to depression and pain. However, the impact of ongoing chemotherapy on sleep is not investigated. Aim: To study the relationship between insomnia and chemotherapy after analysing confounding variables. Materials and Methods: Consecutive patients who visited New England Oncology Clinic in Tamworth were recruited. Insomnia was assessed with the Bergen insomnia scale. The Montgomery Asberg Depression rating scale was used to measure depression. Pain was assessed with the Brief Pain inventory. Chronic medical conditions, type of cancer, side effects to chemotherapy, role of steroids and other drugs were studied as confounders. Results: A total of 56 patients participated in the study. Age ranged from 33 to 83 years (mean: 63.6, SD=10.97). There were 29 men and 27 women. 42 patients received at least one form of chemotherapy and 15 were receiving radiotherapy at the time of assessment. Mean insomnia score was significantly higher in those receiving chemotherapy than in those without chemotherapy (8.92 vs 17.2, two tailed p=0.005, 95% CI=2.63-13.71). There was no significant variation in insomnia scores in terms of chronic medical condition, type of cancer, psychiatric history, use of steroids or adverse effects of chemotherapy. However, total insomnia score was correlated with depression rating score (Pearson correlation, r=0.39, p=0.003) and magnitude of pain (r=0.37, p=0.006). On regression analysis only pain was found to be predictive of insomnia. Conclusions: Insomnia in patients with cancer is found to be associated with concurrent chemotherapy and correlated with degree of depression and pain. Identifying factors related to insomnia in cancer population has implications in its management and patient education.