Insomnia in cancer: its associations and implications

Aim: Insomnia is common in patients with cancer, occurring in 30-50% of cancer population. In spite of this high prevalence it is less studied. Existing data suggests that insomnia is related to depression in cancer patients. However, its relation to ongoing chemotherapy is not investigated. In this study we aimed to study the relationship between insomnia and chemotherapy after analysing confounding variables.

Method: Consecutive patients who visited New England oncology clinic in Tamworth were recruited. Institutional review board approved the study. Insomnia was assessed by Bergen insomnia scale. Montgomery Asberg Depression rating scale was used for depression. In addition to this pain was assessed by brief pain inventory. Chronic medical conditions, type of cancer, side effects to chemotherapy, role of steroids and other drugs were studied as confounders.

Results: 56 patients participated the study. Age ranged from 33 years 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. One or more chronic medical condition was present in 21 patients and 11 had a psychiatric illness. 37 patients were taking steroids and 13 were on sleeping medications. Mean insomnia score was significantly higher in those receiving chemotherapy than in those without chemotherapy (8.92 vs. 17.2, two tailed p=0.024, 95% CI=-1.09-15.24). There was no significant difference in insomnia score 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=0.33, p=0.03).

Conclusions: Insomnia in patients with cancer is found to be associated with concurrent chemotherapy and correlated with degree of depression. Identifying factors related to insomnia in cancer population has implications in its management and patient education.