Sleep disorders and risk of hospitalization in patients with mood disorders: Analysis of the National Sample Cohort over 10 years.

Medical utilization due to organic sleep disorders has increased remarkably in South Korea, which may contribute to the deterioration of mental health in the population. We analyzed the relationship between organic sleep disorders and risk of hospitalization due to mood disorder. We used data from the National Health Insurance Service (NHIS) National Sample Cohort 2002-2013, which included medical claims filed for the 15,537 patients who were newly diagnosed with a mood disorder in a metropolitan region, and employed Poisson regression analysis using generalized estimating equation (GEE) models. By the results, there was a 0.53% hospital admission rate among 244,257 patients with outpatient care visits. Patients previously diagnosed with an organic sleep disorder before specific outpatient care had a higher risk for hospitalization. Such associations were significant in females, patients with a longer duration of disease, or those who lived in the largest cities. In conclusion, considering that experiencing a sleep disorder by a patient with an existing mood disorder was associated with deterioration of their status, health policy makers need to consider insurance coverage for all types of sleep disorders in patients with psychological conditions.