How a general population perceives its sleep and how this relates to the complaint of insomnia

The traditional indicators of insomnia (i.e. difficulty initiating sleep, difficulty maintaining sleep, nonrestorative sleep, early morning awakening) were assessed in a representative sample of 1,722 French-speaking Montrealers (Canada) aged 15 to 100 years. These subjects were interviewed over the telephone (81.3% of contacted sample) by means of the Sleep-Eval software. Subjects were classified as either satisfied or dissatisfied with quality of sleep (SQS or DQS), with or without insomnia indicators (+I or -I). Sociodemographics, sleep-wake schedules, evening activities, medication intake, recent medical consultations, and social life were also investigated. DQS subjects composed 17.8% of the population (DQS + I: 11.2%; DQS - I: 6.5%), and 21.7% of subjects were classified as either DQS + I or SQS + I. Overall, 3.8% of subjects reported using a sleep-enhancing medication. Nonrestorative sleep did not significantly distinguish SQS and DQS subjects. The complaint of nonrestorative sleep is not a useful indicator of insomnia, despite its inclusion in all medical classifications. DQS - I and SQS + I subjects defy traditional classifications. A better understanding of sleep complaints and more accurate classifications will help physicians identify patients with insomnia and meet their needs more appropriately.