Insights into young-onset dementia hospitalizations: An 8-year nationwide study using administrative data

To characterize all Portuguese public hospitalizations of patients aged < 65 years with a primary or secondary diagnosis of dementia, based on ICD-9-CM coding.

A retrospective observational study was conducted using a nationwide database encompassing all hospitalizations occurred in Portuguese mainland public hospitals with discharge from 2008 to 2015. Hospitalizations of patients aged 35-64 years with primary or secondary diagnoses of dementia were selected based on ICD-9-CM codes 290.1X-290.4X, 291.2, 292.82, 294.1X, 294.2X, 331.0, 331.1X, 331.82, 333.4 and 046.1, excluding diagnostic codes 317-319, 330.X, 343, 758.0-758.3 and 759.3. Information on age, sex, primary diagnosis, comorbidities (secondary diagnosis), type of admission, length of stay (LoS), in-hospital mortality, suicide attempts, discharge destination, readmissions and dementia etiology was collected.

From 7971 hospitalizations, for 5682 inpatients, the median age was 57.3 years (SD±6.5) and 61.8% were of male patients. Vascular dementia was the most prevalent etiology, followed by Alzheimer's disease. Most admissions were urgent and had a primary diagnosis of 'Delirium, dementia and other cognitive disorders', followed by pneumonia and alcohol-related disorders. Dementia, cerebrovascular disease and diabetes were the most common comorbidities. Overall, 55.4% of admissions were first-time admissions during the study period and the median LoS was 10.0 days (Q1;Q3: 5.0;20.0). Suicide attempts were recorded in 0.6% of the episodes. The in-hospital mortality rate was 9.2% and most patients were discharged home (80.2%).

This study describes the complexity and strain of young-onset dementia hospitalizations providing a detailed overview and recommendations for further research and tailored interventions.