Factors Associated with Sleep Disorder among Korean Cancer Survivors: A Cross-Sectional Study.

Background: The factors associated with sleep disorder are controversial. This study aimed to evaluate the prevalence of sleep disorder and the factors associated with sleep disorder among Korean adult cancer survivors.

Methods: In this cross-sectional study, we collected data on sleep problems as outcome variables, and sociodemographic and clinical information as predictor variables from cancer survivors at two university-affiliated hospitals. Sleep disorder was defined as "a difficulty in sleep initiation or sleep maintenance at least 3 times a week that started after a cancer diagnosis." Multiple logistic regression analysis was performed with odds ratios (OR) and 95% confidence intervals (95% CI) to evaluate the factors associated with sleep disorder.

Results: The participants were 1,893 Korean cancer survivors (mean age, 58.1 years; females 68.0%). The prevalence of sleep disorder among male and female cancer survivors were 16.5% and 20.3%, respectively. An increase of age by 1-year was associated with a 1.04 (95% CI, 1.01-1.07; P=0.011) times higher risk of sleep disorder in males, while an inverse association was found in females. In female survivors, high fear of cancer recurrence (FCR), high anxiety, menopause, and high EuroQol Visual Analog Scale were associated with 1.45 (95% CI, 1.06-1.98; P=0.020), 1.78 (95% CI, 1.25-2.55; P=0.002), 1.70 (95% CI, 1.08-2.67; P=0.022), and 0.59 (95% CI, 0.43-0.82; P=0.002) times higher risk of sleep disorder, respectively. In male survivors, living with a spouse/or partner was associated with 57% (95% CI, 0.20-0.95; P=0.036) lower risk of sleep disorder. Analyses of cancer sites showed that the factors associated with sleep disorder varied across cancer sites.

Conclusion: One-fifth of adult cancer survivors had sleep disorder. Age, menopausal status, FCR, anxiety, living with a spouse or partner, and quality of life were independently associated with sleep disorder in Korean cancer survivors.