Prevalence of insomnia and its clinical correlates in a general population in Turkey.

Aim: The prevalence of insomnia is influenced by environmental factors. This study aimed to investigate the prevalence of insomnia and its sociodemographic and clinical correlates in a general population-based survey in Turkey.

Methods: This population-based study included 4758 subjects among 5021 who participated in the Turkish Adult Population Epidemiology of Sleep Disorders study. Questionnaire items evaluating insomnia were adapted from the International Classification of Sleep Disorders II and the DSM-IV-TR. Subjects with restless legs syndrome were excluded.

Results: Insomnia was found to be associated with older age (18-24 years, 9.8%; 25-44 years, 11.7%; 45-64 years, 13.8%; 65 years or older, 13.9%), lower income level (<500 USD, 16.5%), time spent watching TV (6-8 h or more, 18.4%), tea consumption in the evening (≥6 glasses, 14.5%) and smoking status (current and ex-smoker, both 14.2%) in multiple logistic regression analysis. In respect to other medical disorders, insomnia was significantly associated with the presence of hypertension, diabetes and heart diseases after the adjustment for relevant risk factors for each disease, across all age and sex groups.

Conclusions: Insomnia is a major health problem in our population, affecting subjects in the working age group and those of lower socioeconomic status. It should especially be screened in patients with chronic diseases. A relatively low proportion of insomnia diagnosed as a sleep disorder suggests that this condition and its clinical correlates are possibly under-recognized.