Prevalence, natural course, and risk factors of insomnia comorbid with cancer over a 2-month period.

PURPOSE: This study aimed to assess the prevalence, natural course, and risk factors of insomnia comorbid with cancer over a 2-month period. PATIENTS AND METHODS: All patients scheduled to receive a curative surgery for a first diagnosis of nonmetastatic cancer were approached to participate in the study on the day of their preoperative visit. As part of a larger population-based longitudinal study, 991 cancer patients completed various self-report scales and an insomnia diagnostic interview at the perioperative phase (T1) and 2 months later (T2).
RESULTS: At T1, 28.5% of the patients met the diagnostic criteria for an insomnia syndrome, and 31.0% had insomnia symptoms; these rates decreased to 26.2% and 22.2%, respectively, at T2. The highest rates of insomnia were found in breast cancer patients, whereas the lowest rates were obtained in prostate cancer patients. Findings indicated an incidence rate of 18.6%, a persistence rate of 68.0%, and a remission rate of 32.0%. Female sex and the presence of an arousability trait (predisposing factors), a diagnosis of head and neck cancer, the administration of surgery, and an increase in anxiety symptoms between T1 and T2 (precipitating factors), and higher baseline levels and increases between T1 and T2 in dysfunctional beliefs about sleep, sleep monitoring, and maladaptive sleep behaviors (maintenance factors) were all associated with an increased risk for insomnia incidence.
CONCLUSION: This study confirms the high prevalence of insomnia comorbid with cancer during the 2 months after the perioperative visit and identifies several factors that might be involved in its development.