Insights into Early Onset Dementia: an 8-year nationwide retrospective study using administrative data

Abstract

Objective: 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. Design, Setting and Participants: A retrospective observational study was conducted using a nationwide database encompassing all hospitalizations occurred in Portuguese mainland public hospitals from 2008 to 2015. Hospitalizations of patients aged 35-64 years with primary or secondary diagnoses of dementia were identified and 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. Measurements: Information on age, sex, primary diagnosis, comorbidities, type of admission, length of stay (LoS), in-hospital mortality, suicide attempts, discharge destination, readmissions and dementia etiology was collected. Results: The mean age of the 7971 hospitalizations was 57.3 years (SD6.5) and 61.8% occurred in males. Vascular dementia was the most common 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 observed. Overall, 55.4% of admissions were first-time admissions and the median LoS was 10.0 days (Q1-Q3:5.0-20.0). Suicide attempts were recorded in 0.6% of episodes. While the in-hospital mortality was 9.2%, most patients were discharged to their homes (80.2%). Conclusions: This study offers insights into the complexity and strain of young-onset dementia hospitalizations on healthcare resources, while providing a detailed overview and recommendations for further research and tailored interventions.