Incidence and mortality of alcohol‐related dementia and Wernicke‐Korsakoff syndrome: A nationwide register study

BACKGROUND: Epidemiological data on alcohol‐related cognitive disorders are scarce. Up‐to‐date population‐based incidence and mortality rates for Wernicke‐Korsakoff syndrome (WKS) and alcohol‐related dementia (ARD) are necessary to understand the burden of these diseases. METHODS: We collected diagnostic data from the Finnish Hospital Discharge Register and mortality data from Statistics Finland for all persons aged ≥40 years who had received a diagnosis of WKS (n = 1149) or ARD (n = 2432) between 1998 and 2015 in Finland. We calculated the incidences and mortality in relation to the age‐, sex‐ and calendar year‐matched general population. Causes of death were ascertained from death certificates. RESULTS: For WKS, the incidence per 100,000 person‐years (95% confidence interval (CI)) was 3.7 (3.4–3.9) in men and 1.2 (1.1–1.3) in women. For ARD, the incidence was 8.2 (7.9–8.6) in men and 2.1 (1.9–2.3) in women. The incidence of WKS peaked in people aged 50–59 years and the incidence of ARD in people aged 70–79 years. The standardized mortality ratio (95% CI) was 5.67 (5.25–6.13) in WKS patients and 5.41 (5.14–5.70) in ARD patients. Most of the excess mortality resulted from alcohol‐related causes. CONCLUSIONS: To our knowledge, this is the first study describing population‐based incidence and mortality rates, sex‐segregated data and causes of death in patients with WKS or ARD. Our results establish a point of reference for the incidence of WKS and ARD and show the high mortality and poor prognosis of these disorders.