Study objectives: Global sleep dissatisfaction (GSD) is not part of the habitual insomnia symptoms in epidemiological studies. Furthermore, none of these studies has examined the relative importance of the various factors correlated to sleep dissatisfaction. This study aims to examine the links between GSD and insomnia and to find the factors contributing to GSD.
Design: A cross-sectional telephone survey was conducted in Germany (66 million inhabitants 15 years of age or older) with a representative sample of 4,115 subjects aged 15 years or older. Interviewers used the Sleep-EVAL system. The questionnaire covered several topics that were grouped into six classes of variables identified as potential factors associated with sleep dissatisfaction: sociodemographic descriptors, environmental factors, life habits, health status, psychological factors, sleep/wake factors.
Setting: N/A.
Participants: A representative sample of 4,115 subjects aged 15 years or older
Interventions: N/A.
Measurements and results: Overall, 7% of the subjects reported being GSD; 95.5% of them had at least one insomnia symptom. The duration of insomnia symptom(s) was 20 months longer in GSD subjects compared to insomnia subjects without GSD. The prevalence of GSD was higher in women than in men and increased with age. The most significant predictive factors for GSD were: 1) for sleep/wake schedule variables: night sleep duration less than 6 hours (OR: 4.0 and over) and sleep latency greater than 30 minutes. 2) for sociodemographic variables: age between 65 and 74 (OR: 6.7) 3) for health variables: Upper airway disease (OR: 7.1); 4) for mental health variables: anxiety symptoms (OR: 3.0); 5) for environmental factors: too hot bedroom (OR=2.5) 6) for life habit factors: the need of a particular object in order to fall asleep (OR: 2.4).
Conclusions: This study confirms that GSD is a better indicator of an underlying pathology than the classical insomnia symptoms alone: compared to insomniac subjects without GSD, subjects with GSD were two times more likely to report excessive daytime sleepiness, and eight times more likely to have a diagnosis of sleep or mental disorder. Furthermore, in car drivers, road accidents in the previous year were two times more frequent with GSD drivers as compared to insomnia drivers without GSD. Subjects with GSD were more than 10 times more likely to seek help for their sleep problems and five times more likely to use a sleep medication than insomnia subjects without GSD.