Heterogeneity in estimates of incidence and prevalence of narcolepsy: a systematic review and meta-regression analysis.

Estimates of incidence/prevalence of narcolepsy could not be pooled reliably with substantial heterogeneity. Incidence/prevalence studies using ICSD and Brighton provided lower estimates than studies using ICD and other criteria. Diagnostic criteria should be standardized when comparing or pooling the incidence/prevalence to understand the epidemiology of narcolepsy. Future studies are needed to focus on the at-risk population for the etiology investigation of narcolepsy.