Delirium, Frailty, and Mortality: Interactions in a Prospective Study of Hospitalized Older People

Abstract

BackgroundIt is unknown whether the association between delirium and mortality is consistent for individuals across the whole range of health states. A bimodal relationship has been proposed, where delirium is particularly adverse for those with underlying frailty, but may have a smaller effect (perhaps even protective) if it is an early indicator of acute illness in fitter people. We investigated the impact of delirium on mortality in a cohort simultaneously evaluated for frailty.MethodsWe undertook an exploratory analysis of a cohort of consecutive acute medical admissions aged ≥70. Delirium on admission was ascertained by psychiatrists. A frailty index (FI) was derived according to a standard approach. Deaths were notified from linked national mortality statistics. Cox regression was used to estimate associations between delirium, frailty, and their interactions on mortality.ResultsThe sample consisted of 710 individuals. Both delirium and frailty were independently associated with increased mortality rates (delirium: HR 2.4, 95% CI 1.8–3.3, p < .01; frailty (per SD): HR 3.5, 95% CI 1.2–9.9, p = .02). Estimating the effect of delirium in tertiles of FI, mortality was greatest in the lowest tertile: tertile 1 HR 3.4 (95% CI 2.1–5.6); tertile 2 HR 2.7 (95% CI 1.5–4.6); tertile 3 HR 1.9 (95% CI 1.2–3.0).ConclusionAlthough delirium and frailty contribute to mortality, the overall impact of delirium on admission appears to be greater at lower levels of frailty. In contrast to the hypothesis that there is a bimodal distribution for mortality, delirium appears to be particularly adverse when precipitated in fitter individuals.

How do potentially inappropriate medications and polypharmacy affect mortality in frail and non-frail cognitively impaired older adults? A cohort study

“…Incorporating frailty assessment into primary care is increasingly encouraged to identify individuals at greater risk of mortality, hospitalisation and susceptibility to adverse health outcomes 10. An important aspect of the validity of frailty measures is whether they can predict resilience or susceptibility to other potential risk factors 9. Recent findings suggest that polypharmacy and frailty are associated with mortality, incident disability and hospitalisation compared with non-frail participants without polypharmacy 11.…”

Impact of a Premorbid Psychiatric Disorder on the Incidence of Delirium during ICU Stay, Morbidity, and Long-Term Mortality

“…The aetiology of delirium in the ICU setting is considered to be multifactorial. Not only premorbid factors such as age, frailty, alcohol/drug abuse, and severity of underlying disease play a role [6, 7], but also precipitating factors (e.g., metabolic disorders, sepsis, and hypotension) as well as the administration of drugs (e.g., benzodiazepines and anticholinergic drugs) are believed to contribute to both incidence and severity of delirium [8]. In case delirium is suspected or established, a multimodality approach has been advocated, especially since pharmacologic interventions have been proven to be cumbersome, in terms of both prevention and treatment [9–11].…”

Associations between Frailty and Delirium among Older Patients Admitted to an Emergency Department

“…Delirium is characterized by fluctuating disturbances in arousal, a sudden and rapid onset, trouble concentrating, and cognition secondary to an acute medical condition; it is common and affects 8–17% of older patients attending ED and 51% of patients in postacute care [21]. This syndrome has some important common consequences compared with frailty, such as a loss of executive function leading to falls, increased rehospitalizations, institutionalizations, and premature death [22, 23, 24, 25, 26, 27]. Delirium in the ED among older patients has negative consequences and is an independent predictor of prolonged hospitalizations and early death [28, 29].…”

“…The rapid detection of geriatric syndromes in the ED, such as frailty and delirium, is related to awareness and risks of an increased length of stay, more adverse effects, increased admissions and readmissions, and increased mortality [21]. Frailty and delirium would appear to be two clinically distinct geriatric syndromes; however, their simultaneous onset has often been documented in the scientific literature [20, 24, 25]. Few studies have explored the associations between frailty and delirium on admission to Swiss ED [31, 32, 33, 34, 35].…”