Factors associated with duration before receiving definitive diagnosis of narcolepsy among Japanese patients affected with the disorder.

Background: Narcolepsy (NA) is a sleep disorder characterized by excessive daytime sleepiness and an increased propensity of rapid eye movement sleep. If left untreated, NA can lead to academic underachievement or job loss because of dozing off or mistakes caused by inattentiveness due to sleepiness.

Purpose: Although untreated narcolepsy patients may suffer from many social disadvantages due to excessive daytime sleepiness, mostly it takes a long time to receive a definitive diagnosis of the disorder. This retrospective study investigated factors related to the period until definitive diagnosis among patients with narcolepsy in Japan.

Methods: We enrolled 181 consecutive patients (108 men, 73 women; mean age 37.6 ± 16.6 years old; narcolepsy with cataplexy/narcolepsy without cataplexy = 131:50). Multivariate logistic regression analysis was performed with period until definitive diagnosis as the dependent variable and descriptive clinical variables as the independent variables.

Results: The mean period until receiving the diagnosis among the participants was 9.9 ± 10.1 years. More than half of the patients first learned about the disorder from information provided by the media. Multivariate logistic analysis indicated that adult onset (p < 0.01), onset in 1995 or later (p < 0.001), and first learning about the disorder from a sleep disorder specialist physician or a general practitioner (p < 0.001) were associated with a time taken for receiving a definitive diagnosis less than or equal to the median value (7 years).

Conclusion: Improving access to information about the concept of the disorder and the medical institutions specialized in sleep disorders, especially via the Internet, would be necessary to promote early diagnosis of the disorder.