Mortality in people with dementia, delirium, and unspecified cognitive impairment in the general hospital: prospective cohort study of 6,724 patients with 2 years follow-up

Abstract

PurposeCognitive impairment is common in older people admitted to hospital, but the outcomes are generally poorly understood, and previous research has shown inconsistent associations with mortality depending on the type of cognitive impairment examined and duration of follow-up. This study examines mortality in older people with any cognitive impairment during acute hospital admission.Patients and methodsProspective cohort of 6,724 people aged ≥65 years with a structured cognitive assessment on acute admission were included in this study. Cognitive spectrum disorder (CSD) was defined as delirium alone, known dementia alone, delirium superimposed on known dementia, or unspecified cognitive impairment. Mortality associated with different types of CSD was examined using a non-proportional hazards model with 2-year follow-up.ResultsOn admission, 35.4% of patients had CSD, of which 52.6% died within 2 years. After adjustment for demographics and comorbidity, delirium alone was associated with increased mortality in the 6 months post-admission (HR =1.45, 95% CI 1.28–1.65) and again after 1 year (HR =1.44, 95% CI 1.17–1.77). Patients with known dementia (alone or with superimposed delirium) had increased mortality only after 3 months from admission (HR =1.85, 95% CI 1.56–2.18 and HR =1.80, 95% CI 1.52–2.14) compared with patients with unspecified cognitive impairment after 6 months (HR =1.55, 95% CI 1.21–1.99). Similar but partially attenuated associations were seen after adjustment for functional ability.ConclusionMortality post-admission is high in older people with CSD. Immediate risk is highest in those with delirium, while dementia or unspecified cognitive impairment is associated with medium- to long-term risk. These findings suggest that individuals without dementia who develop delirium are more seriously ill (have required a larger acute insult in order to precipitate delirium) than those with pre-existing brain pathology (dementia). Further research to explain the mortality patterns observed is required in order to translate the findings into clinical care.

Association of Cognitive Impairment and Elderly Mortality: Differences between two cohorts ascertained 6-years apart in China

“…Although a number of epidemiological studies have reported on a cognitive impairment-mortality relationship 3,7 , most of them concerned the association of cognitive impairment and mortality risk of elders in high-income contries [8][9][10][11][12] . In upper-middle income countries such as China, several studies have indicated that baseline cognitive impairment increases the risk of all-cause mortality 13,14 .…”

Are antidementia drugs associated with reduced mortality after a hospital emergency admission in the population with dementia aged 65 years and older?

“…There is no previous reporting on associations between antidementia treatment and mortality after admission in this high-risk population of in-patients. People with dementia experience poor outcomes after hospitalization, with higher mortality than people with no dementia [27] , [28] . The present study shows for the first time that treatment with antidementia drugs is associated with reduced mortality in the population with dementia.…”

“…Many people with dementia are admitted to care homes from the acute hospital [26] . In the acute hospital setting, people with dementia have poor outcomes; they have longer hospital stays [27] , an increased risk of not returning home [26] , and high mortality [28] .…”

Mortalität von Patientinnen und Patienten auf einer Abteilung für Alterspsychiatrie in Graz, Österreich – Eine retrospektive Fall-Kontroll-Studie

“…Eine systematische Literaturübersicht gibt folgende Variablen für einen schlechten Outcome an: Länge des Delirs, motorisch hypoaktiver Subtyp, Schwere des Delirs, vorbestehende psychiatrische Erkrankungen wie Demenz und Depression [14]. In der Literatur gibt es Hinweise, dass Spitalspatienten ohne Demenz, die ein Delir entwickeln, schwerer erkrankt sind als diejenigen mit vorbestehenden Hirnpathologien [15]. Allerdings zeigten van Roessel et al [16] Die in diesem Artikel enthaltenen Bilder und sonstiges Drittmaterial unterliegen ebenfalls der genannten Creative Commons Lizenz, sofern sich aus der Abbildungslegende nichts anderes ergibt.…”