Association of Diagnosed Dementia with Post-discharge Mortality and Readmission Among Hospitalized Medicare Beneficiaries

Abstract

Background: Patients with dementia are frequently hospitalized and may face barriers in post-discharge care.

Objective: To determine whether patients with dementia have an increased risk of adverse outcomes following discharge.

Design: Retrospective cohort study.

Subjects: Medicare beneficiaries hospitalized in 2016.

Main measures: Co-primary outcomes were mortality and readmission within 30 days of discharge. Multivariable logistic regression models were estimated to assess the risk of each outcome for patients with and without dementia accounting for demographics, comorbidities, frailty, hospitalization factors, and disposition.

Key results: The cohort included 1,089,109 hospitalizations of which 211,698 (19.3%) were of patients with diagnosed dementia (median (IQR) age 83 (76-89); 61.5% female) and 886,411 were of patients without dementia (median (IQR) age 76 (79-83); 55.0% female). At 30 days following discharge, 5.7% of patients with dementia had died compared to 3.1% of patients without dementia (adjusted odds ratio (aOR) 1.21; 95% CI 1.17 to 1.24). At 30 days following discharge, 17.7% of patients with dementia had been readmitted compared to 13.1% of patients without dementia (aOR 1.02; CI 1.002 to 1.04). Dementia was associated with an increased odds of readmission among patients discharged to the community (aOR 1.07, CI 1.05 to 1.09) but a decreased odds of readmission among patients discharge to nursing facilities (aOR 0.93, CI 0.90 to 0.95). Patients with dementia who were discharged to the community were more likely to be readmitted than those discharged to nursing facilities (18.9% vs 16.0%), and, when readmitted, were more likely to die during the readmission (20.7% vs 4.4%).

Conclusions: Diagnosed dementia was associated with a substantially increased risk of mortality and a modestly increased risk of readmission within 30 days of discharge. Patients with dementia discharged to the community had particularly elevated risk of adverse outcomes indicating possible gaps in post-discharge services and caregiver support.

Figure 1

Primary diagnoses of hospital readmissions among Medicare beneficiaries with and without diagnosed dementia.

Figure 2

Disposition of patients with dementia following unplanned readmissions. Note: Readmissions exclude planned readmissions and include hospital observation stays. 116 readmissions resulted in patients leaving against medical advice not depicted on graph due to low sample size (98 following initial community discharge; 18 following initial facility discharge). Chi-2 test of difference in proportions of patients initially discharged to the community compared to those initially discharged to a facility P<0.001.