The impact of depression in Alzheimer's disease hospitalized patients: a nationwide study

Abstract

Objectives: To characterize depression among hospitalizations with a registered diagnosis of Alzheimer's disease (AD) and explore its association with hospitalization outcomes. Methods: A retrospective observational study was performed using administrative data from all mainland Portuguese public hospitals. Episodes of inpatients ≥65 years old, discharged between 2008-2015, with a primary or secondary AD diagnosis (ICD-9-CM 331.0) were selected. Codes 296.2X, 296.3X and 311 were used to identify episodes with concomitant depression. Hospitalizations with depression were matched to episodes without depression by performing a 1:1 propensity score matching (PSM). Univariable and multivariable approaches were used for data analysis. Results: From 61361 hospitalizations with AD diagnosis, 1637 (2.7%) had a depression code. Greater odds of depression were observed for women (aOR=1.882; 95%CI=1.682-2.106) and patients with higher Charlson Comorbidity Index (aOR=1.092; 95%CI=1.059-1.126). After 1:1 PSM, episodes with a depression register presented higher lengths of stay (aOR=1.304; 95%CI=1.120-1.519), estimated hospitalization charges (aOR=2.989; 95%CI95=2.541-3.515), and were more likely to be discharged home (aOR=1.528; 95%CI=1.247-1.871). No association was found in in-hospital mortality. Conclusions: Depression comorbidity was associated with episodes' duration and charges, and patients' discharge destination. Clinical implications: The importance of targeting AD-related depression is highlighted, as it can prevent worse patients' outcomes and increased healthcare costs.