All-Cause and Cause-Specific Mortality Among Patients With Narcolepsy.

Abstract

Importance: Narcolepsy is a sleep disorder potentially affecting mortality, yet evidence on this association remains sparse.

Objective: To examine whether narcolepsy is associated with an increased risk of all-cause and cause-specific mortality.

Design, setting, and participants: This retrospective cohort study used data from the Taiwan National Health Insurance Research Database (NHIRD) from 2001 to 2021, with patients followed up until death or December 31, 2022. Patients were aged 6 years or older with 2 or more narcolepsy diagnoses from psychiatrists or neurologists. Controls were selected from the NHIRD as a population-based sample. Controls without narcolepsy were matched in a 1:4 ratio on sex and birth date (±6 months). Sibling controls were siblings without narcolepsy. Statistical analysis was performed from January to April 2025.

Exposures: Clinical narcolepsy diagnosis, confirmed via NHIRD records (International Classification of Diseases, Ninth Revision, Clinical Modification code 347 or International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, Clinical Modification code G47.4).

Main outcomes and measures: The primary outcome was all-cause mortality, measured as hazard ratios (HRs) using Cox proportional hazards regression, adjusted for birth year, sex, income, urbanization, and Charlson Comorbidity Index. Secondary outcomes included cause-specific mortality (natural, unnatural, accidents, suicides).

Results: Of 3187 patients with narcolepsy (mean [SD] age, 29.5 [16.1] years; 1674 male patients [52.5%]) and 12 748 controls (mean [SD] age, 29.5 [16.1] years; 6696 male patients [52.5%]), 132 patients with narcolepsy and 456 controls died. Psychiatric comorbidities, especially depression (1167 of 3187 [36.6%] vs 861 of 12 748 [6.8%]) and anxiety (1054 of 3187 [33.1%] vs 853 of 12 748 [6.7%]), were more common in the narcolepsy group than in the control group. Crude all-cause mortality rates were 44.3 per 10 000 person-years among patients with narcolepsy and 38.1 per 10 000 person-years among controls. All-cause mortality was not increased among patients with narcolepsy (HR, 0.96; 95% CI, 0.79-1.17). There was no increase among patients with narcolepsy in cause-specific mortality for natural causes (HR, 0.90; 95% CI, 0.73-1.11), unnatural causes, (HR, 1.41; 95% CI, 0.83-2.40), accidents (HR, 1.37; 95% CI, 0.64-2.95), and suicides (HR, 1.41; 95% CI, 0.62-3.22). The sibling cohort analysis similarly demonstrated no significantly increased risk among patients with narcolepsy of all-cause mortality (HR, 1.14; 95% CI, 0.63-2.06) or cause-specific mortality from natural causes (HR, 0.66; 95% CI, 0.28-1.56), unnatural causes (HR, 2.08; 95% CI, 0.87-4.98), accidents (HR, 1.61; 95% CI, 0.48-5.37), or suicides (HR, 3.43; 95% CI, 0.88-13.28).

Conclusions and relevance: In this cohort study of Taiwanese residents, narcolepsy was not associated with excess all-cause or cause-specific mortality. These findings reduce immediate clinical concern, but the wide 95% CIs suggest that a modest increase in risk cannot be excluded; replication in other populations with longer follow-up is warranted.