Epidemiology of Insomnia in Korean Adults: Prevalence and Associated Factors

BACKGROUND AND PURPOSE Insomnia is a common complaint in adults. However, large epidemiologic studies of insomnia involving Asian populations are rarely reported. We performed an epidemiologic study of insomnia in a large Korean adult population. METHODS A total of 5,000 subjects (2,470 men and 2,530 women) were interviewed by telephone. A representative sample of subjects aged 20 to 69 years was constituted according to a stratified, multistage random sampling method. Insomnia was defined as either any difficulty getting to sleep or getting back to sleep after waking in the night. RESULTS More than one fifth (n=1,141, 22.8%) of the 5,000 subjects complained of insomnia, with the prevalence being significantly higher in women (25.3%) than in men (20.2%, p<0.001). Logistic regression revealed that the prevalence of insomnia increased significantly with age (p<0.001), being higher in those aged 60-69 years than in those aged 20-29 years (OR=2.368, 95% CI=1.762-3.182, p<0.001), and was lower in those with a monthly income of >4.5 million Korean won than in those with an income of <1.5 million Korean won (OR=0.689, 95% CI=0.523-0.906, p<0.01). CONCLUSIONS Insomnia is a common complaint in Korean adults, and its prevalence is similar to that in adults in Western countries.