Increasing Hospitalizations for Wernicke Encephalopathy in Spain: A Nationwide Population-Based Study

Background/Objectives: Wernicke encephalopathy (WE) is an acute neurological syndrome caused by severe thiamine deficiency. Early detection is challenging due to the low sensitivity of the classic triad. Methods: This retrospective observational study used the Spanish Minimum Basic Data Set, including hospital admissions with a primary diagnosis of WE (2016-2022). Demographic, clinical, and economic variables were also analyzed. Severity of illness (SOI) and risk of mortality (ROM) were assessed using the All Patient Refined Diagnosis-Related Groups (APR-DRG) system. Results: A total of 2477 WE episodes were included (1864 men; mean age, 58.2 years; standard deviation [SD], 11.0). The hospital admission rate increased by an average of 16% per year (incidence rate ratio [IRR], 1.16; p < 0.001). The proportion of foreign-born patients increased significantly over the study period. Most patients were discharged home (1868; 75.4%), whereas transfers to residential care facilities increased over time. The mean hospital stay was 19.0 days (SD 36.5). In-hospital mortality was 3.7%. In multivariable analysis, malnutrition (odds ratio [OR] 1.64), cancer (OR 2.11), and active infection (OR 5.79) were independently associated with mortality. The incorporation of ROM into the mortality model markedly improved discrimination, and mortality increased progressively with higher ROM categories: moderate (OR 3.45), major (OR 11.76), and extreme (OR 38.76) (all p < 0.001). Conclusions: WE is an increasingly frequent cause of neurological hospitalization in Spain, associated with a substantial clinical and economic burden. In-hospital mortality is driven mainly by overall clinical complexity and comorbidity burden rather than by WE in isolation.