Quality of sleep and chronic illnesses.

The association between sleep complaints and chronic illnesses was investigated in several patient groups, including type-2 diabetics, patients with recent myocardial infarction, chronic paraplegia, affective disorders or rheumatic (musculoskeletal) disorders. Sleeping habits and complaints were investigated by questionnaire. All diagnoses were established by the rehabilitation team of the Rehabilitation Research Centre (RRC). The prevalence of difficulty in initiating sleep (DIS) and difficulty in maintaining sleep (DMS) was slightly higher in the myocardial infarction group than in their respective matched control group, whereas patients with paraplegia or an affective disorder suffered markedly from various sleep disorders. Patients with rheumatic illness reported sleep disorders significantly less often than patients with affective disorder, though on admission both groups complained of similar somatic symptoms and poor sleep. Organic disease per se does not explain the prevalence of sleep disorders in patients with chronic illnesses. Psychological and social factors seem to contribute significantly to the prediction of sleep disorders in patients with chronic illnesses.