Figure 2. The different time intervals from the vaccination to the onset of narcolepsy depending on the definition of the onset time point, i.e. a) estimated onset time based on the extensive review of the patient records by a sleep and/or narcolepsy specialist, and closest to the parental/patient recall; b) first recorded contact to health care because of excessive sleepiness; c) date of referral to paediatrician or pediatric neurologist; and d) date of setting the diagnosis of narcolepsy, ICD-10 G47.4.