Lifelines participants (or their parents, in case of underage participants) were asked whether they suffered from insomnia (section: Diseases & symptoms).
In the context of an additional assessment, ADHQ, the Minimal Insomnia Symptom Scale (MISS) was used1)
Other sleeping habits of participants were assessed with several general questions as well as the Munich ChronoType Quesitonnaire, the Pittsburgh Sleep Quality Index and the Epworth Sleepiness Scale.