Delirium as a predictor of mortality in US Medicare beneficiaries discharged from the emergency department: a national claims-level analysis up to 12 months

Abstract

BackgroundDelirium is common among seniors discharged from the emergency department (ED) and associated with increased risk of mortality. Prior research has addressed mortality associated with seniors discharged from the ED with delirium, however has generally relied on data from one or a small number of institutions and at single time points.ObjectivesAnalyse mortality rates among seniors discharged from the ED with delirium up to 12 months at the national level.DesignRetrospective cohort study.SettingAnalysed data from the Centers for Medicare & Medicaid Services limited data sets for 2012–2013.ParticipantsMedicare fee-for-service beneficiaries aged 65 years or older discharged from the ED. We focused on new incident cases of delirium, patients with any prior claims for delirium, hospice claims or end-stage renal disease were excluded. Sample size included 26 245 delirium claims, and a randomly selected sample of 262 450 controls.Outcome measuresMortality within 12 months after discharge from the ED, excluding patients transferred or admitted as inpatients.ResultsAmong all beneficiaries, 46 508 (16.1%) died within 12 months, of which 39 404 (15.0%) were in the non-delirium (ie, control group) and 7104 (27.1%) were in the delirium cohort, respectively. Mortality was strongest at 30 days with an adjusted HR of 4.82 (95% CI 4.60 to 5.04). Over time, delirium was consistently associated with increased mortality risk compared with controls up to 12 months (HR 2.07; 95% CI 2.01 to 2.13). Covariates that affected mortality included older age, comorbidity and presence of dementia.ConclusionsOur results demonstrate delirium is a significant marker of mortality among seniors in the ED, and mortality risk is most salient in the first 3 months following an ED visit. Given the significant clinical and financial implications, there is a need to increase delirium screening and management within the ED to help identify and treat this potentially fatal condition.

Delirium

“…Delirium is strongly associated with multiple adverse outcomes. These outcomes may be short-term effects, such as falls, aspiration pneumonia, distress and other events occurring during delirium or in the days following delirium 2,297,298 , or increased short-term mortality 27,240,248,299 . Evidence also exists for an association between delirium and worse long-term outcomes, such as increased 1-year mortality and disability 300,301 .…”

Cognitive decline after elective and nonelective hospitalizations in older adults

“…30 While these events may have an important role, they were reported in very limited number in these claims and thus we were unable to investigate their influence. For example, only 16 participants had delirium as indicated by ICD-9 codes, 31 which likely underestimates the actual prevalence of hospital-related delirium in this cohort.…”

Evaluation of a co-produced delirium awareness programme for undergraduate nursing students in Northern Ireland: a pre-test/post-test study

“…However, despite delirium becoming a growing global healthcare concern [4][5][6], it is frequently under diagnosed in primary, secondary and tertiary care [7,8]. Importantly, delirium is a symptom of acute illness that is often avoidable and reversible [9,10]. Early recognition of delirium is essential to enable healthcare professionals to identify reversible causes and appropriate intervention tailored to the individual needs of the person.…”