Study objectives: The Cologne Children's Sleep Study intended to provide information on prevalence and course of difficulties of initiating and maintaining sleep in childhood.
Design: Longitudinal study.
Setting: Children of the fourth grade of elementary schools in Cologne.
Participants: 832 children and their parents; the mean age of the children was 9.4, 10.7, and 11.7 years at the 3 assessments.
Measurements and results: Children and parents were surveyed using questionnaires 3 times on an annual basis. In self- and parental reports, about 30%-40% of the children of the longitudinal sample had problems falling asleep at the first assessment. One year later, about 30% to 40% of these children did not describe any difficulties initiating sleep, whereas about 60% did report continuing difficulties initiating sleep. Difficulties maintaining sleep are less common in childhood. The analysis of self- and parental reports revealed that in general children described significantly more difficulties initiating and maintaining sleep than their parents report.
Conclusions: Difficulties initiating and maintaining sleep may be transient or persistent. In practice, children and adolescents should be included in the diagnostic and therapeutic process.