[Epidemiological study of sleep disorders in patients in Swiss general practice]

The aim of the study was to assess the prevalence, severity, associated factors and diagnosis of sleep disorders in general practice. Over 700 patients were investigated with a multiple choice questionnaire in 24 general practices in Switzerland. To assess sleep disorders, criterion A for insomnia according DSM-III-R was applied. The prevalence of sleep disorders was 44%, 64% of these were classified as mild, 31% as moderate and 5% as severe. 50% of the female patients complained about insomnia compared to 36% in males. Retrospectively, 74% of the patients stated having suffered from sleep disorders for more than one year (mild 76%, moderate 69%, severe 75%). 70% of patients with mild, 42% with moderate and 30% of patients with severe insomnia didn't inform their physicians about their sleep difficulties on the occasion of an earlier consultations. Patients with moderate or severe insomnia felt moderately or markedly disabled in their quality of life (71%) and work (58%). To estimate general anxiety and depressive state, self-rating scales were used (STAI, D-S). In comparison to reference values for healthy volunteers, insomniac patients had significantly higher scores on both scales, which were associated with the severity of sleep disorders, corroborating the association of sleep disorders with anxiety disorders and depressions. The physicians diagnosed in 18% of insomniacs a psychiatric disease, in 52% a psychoreactive disorder and in 26% a somatic etiology. The study shows that sleep disorders are a frequent syndrome in general practice and often not reported to the physician; therefore, the patients should routinely be questioned about sleep problems, and associated psychiatric diseases should be considered.