Method: A cohort population-based study with nested case-control analysis was conducted in adults using the UK General Practice Research Database. Information was collected for 12437 patients with a new sleep disorder diagnosis and 18350 age- and sex-matched controls. Logistic regression analysis was used to compute odds ratios (OR) and 95% confidence intervals (CI).

Results: The incidence of a new sleep disorder diagnosis was 12.5 per 1000 person-years. There was a clear association of sleep disorders with smoking and excessive alcohol consumption; prior psychiatric disorders including stress (OR: 3.6; 95% CI: 2.9-4.4) and depression (OR: 3.1; 95% CI: 2.8-3.3); prior circulatory diseases including heart failure (OR: 1.8; 95% CI: 1.4-2.2) and coronary heart disease (OR: 1.4; 95% CI: 1.2-1.6); prior gastrointestinal diseases including gastroesophageal reflux disease (OR: 1.4; 95% CI: 1.2-1.7) and irritable bowel syndrome (OR: 1.4; 95% CI: 1.3-1.6). Use of hypnotics and antidepressants was increased in the year after diagnosis. Relative 1-year mortality risk was 2.9-fold higher in the sleep disorder group than in controls, with a noticeably higher proportion of deaths due to suicide.

Conclusion: The fact that sleep disorders were associated with several morbidities, most strongly with psychiatric disorders, as well as with increased mortality, underscores the importance of sleep problems as indicators of health status.