Objectives: To analyse simultaneously sleep habits and sleep disturbances in an elderly population and numerous factors possibly affecting sleep at the same time.
Design: A cross-sectional epidemiological survey by means of questionnaires.
Setting: The capital city of Iceland, Reykjavík and surrounding suburbs.
Participants: A randomly selected, but stratified sample with 100 men and 100 women in each 5-year age group of the ages 65-84 years--800 individuals altogether.
Main outcome measure: Sleep habits and sleep disturbances.
Results: The mean duration of sleep was 7.25 h (SD 74 min). Mean sleep onset time was 00.13 hours and was not related to age and gender but was delayed at weekends. Daytime napping was reported by 50% of the men and 31% of the women (P < 0.001). Difficulty maintaining sleep (DMS) was the most commonly reported insomnia complaint (men 37% and women 30%). Sleep charts revealed that men woke up an average of 1.2 times per night but women 0.8 times per night (P < 0.01). Difficulty initiating sleep was reported by 9.6% and early morning awakening (EMA) by 16.7%. Pain was a strong factor contributing to EMA. There was also an increase in EMA complaints among the elderly with obstructive pulmonary diseases and systemic hypertension. The prevelance of insomnia was only partly related to age and gender. Multiple regression analyses, however, showed different interrelationships between insomnia and other symptoms and findings for men versus women.
Conclusion: DMS is the most commonly reported insomnia complaint among the elderly (men 37% and women 30%). The prevalence of insomnia did not increase with age in our study group.