Sleep complaints cosegregate with illness in older adults: clinical research informed by and informing epidemiological studies of sleep.

OBJECTIVE: The more recent epidemiological studies of sleep complaints have shown that when factors such as physical and psychiatric illness, medication use and drug and alcohol use are accounted for, the age-related increase in prevalence of sleep complaints is strikingly less than in those earlier studies without such controls. In an effort to support this finding, we examined the relationships between clinical health screenings and sleep complaints and disorders in two large groups of potential research volunteers (total N=2954).
METHODS: As part of a study of older adults at risk for Alzheimer's disease, two large groups of potential research volunteers (n=1619 and 1335, respectively) replied to advertisements that made no mention of sleep and underwent three increasingly rigorous levels of health screening. At each level of screening, medical and psychiatric health and history were assessed and, where appropriate, subjects were excluded from further study participation before any mention of sleep quality or sleep complaint was made. The remaining subjects then underwent polysomnography.
RESULTS: Of 1619 elderly adult volunteers screened in this manner, only 51 (3.14%) were found to have significant sleep complaints or disorders. The second group of 1335 screened in this manner revealed a similar pattern with only 18 (1.35%) having significant sleep complaints or disorders.
CONCLUSIONS: These findings indicate that careful health assessments will screen out most sleep complaints and disorders in the older population and lend further support to the epidemiological evidence demonstrating that the bulk of geriatric sleep complaints and disorders is not the result of age per se, but rather cosegregates with medical and psychiatric disorders and related health burdens.