Epilepsy hospitalizations and mental disorders: a Portuguese Population-based Observational Retrospective Study (2008-2015)

Abstract

Background: Epilepsy is a group of neurological disorders characterized by a predisposition to recurrent seizures and has been associated with several somatic and psychiatric comorbidities. The latter are highly frequent in patients with epilepsy (PWE) and were found to be markers of poorer prognosis. They can lower the seizure threshold, increase the risk of treatment-resistant epilepsy, reduce patients' function and quality of life, and increase the use of healthcare resources, including emergency department visits and inpatient care. Despite this, there is little information on healthcare utilization associated with a wide range of comorbid mental disorders in PWE. Objective: To characterize registered mental disorders among all hospitalizations that occurred between 2008 and 2015 in mainland Portugal with a primary diagnosis of epilepsy and to analyze their association with key hospitalization outcomes. Methods: An observational retrospective study was performed using administrative data from hospitalization episodes of patients discharged between 2008 and 2015 from Portuguese public mainland hospitals. All episodes with epilepsy as the primary diagnosis (ICD-9-CM code 345.X) were selected. Data analysis, reporting, and manuscript formatting followed the Reporting of studies Conducted using Observational Routinely-collected Data (RECORD) guidelines. Mental disorders as secondary diagnoses were identified and grouped according to Clinical Classification Software (CCS) categories. For each episode, data regarding hospitalization outcomes were retrieved, including length of stay (LoS), in-hospital mortality, 8-year period readmissions, and total estimated charges. Results: Overall, 27,785 hospitalizations with a primary epilepsy diagnosis were analyzed. The median age at admission was 47.0 (Q1:21.0; Q3:69.0) years, and episodes mostly referred to males (54.3%). Median LoS was 4.0 (Q1: 2.0; Q3: 8.0) days, in-hospital mortality was 2.4%, the percentage of readmissions was 24.3%, and median episodes' charges were 1,324.4 (Q1:1,324.4; Q3:1,578.7) euros. A total of 9,423 (33.9%) episodes had registered mental disorders, with alcohol-related disorders being the most prevalent (11.7%), followed by delirium, dementia, and amnestic and other cognitive disorders (8.2%), and developmental disorders (6.0%). For episodes with a concomitant register of a mental disorder, LoS was significantly longer (5.0 (Q1:2.0; Q3:9.0) vs. 4.0 (Q1:2.0; Q3:7.0) days), and in-hospital mortality was higher (2.8% vs. 2.2%), as were readmissions (25.5% vs. 23.7%), and median episodes' charges (1,578.7 (Q1:1,324.4; Q3:1,578.7) vs. 1,324.4 (Q1:1,293.0; Q3:1,578.7) euros).

Conclusion: Epilepsy-related hospitalizations with registered mental disorders heightened the utilization of healthcare resources since they were associated with longer hospital stays, higher in-hospital mortality, readmissions, and health expenditures, stressing the importance of diagnosing and treating mental disorders in PWE.