A Systematic Review and Meta-Analysis Examining Pneumonia-Associated Mortality in Dementia

Abstract

Background: Although it is generally accepted that deaths associated with pneumonia are more common in patients with dementia, no comprehensive reviews on the subject have previously been published. Summary: Relevant studies were identified through a literature search of the PubMed, EMBASE, Scopus, and ISI Web of Science databases for publications up to August 2013. Studies were included if (1) a group of adult subjects with dementia and a (comparison) group composed of subjects without dementia were included, (2) the cause(s) of death was/were reported, and (3) pneumonia was identified as one of the possible causes of death. The occurrence of death due to pneumonia associated with dementia was expressed as an odds ratio (OR) with 95% confidence interval (CI). Thirteen studies were included. The odds of death resulting from pneumonia were significantly increased for persons with any form of dementia compared with those without dementia (OR = 2.22, 95% CI 1.44-3.42, p < 0.001). In a subgroup analysis, using the results from 8 studies that restricted inclusion to persons with Alzheimer's disease, the odds of death resulting from pneumonia were also significantly higher (OR = 1.70, 95% CI 1.12-2.58, p = 0.013). Key Messages: The odds of pneumonia-associated mortality were increased more than 2-fold for patients with dementia. © 2014 S. Karger AG, Basel

Association between dementia and discharge status in patients hospitalized with pneumonia

“…Previous reports on dementia and in-hospital mortality in elderly people with pneumonia showed mixed results. Several studied showed patients with dementia were at higher risk of mortality after pneumonia [9,26], whereas a previous prospective study showed impaired cognitive function was not significantly associated with in-hospital death in patients aged ≥75 years [12]. In our study, patients with dementia hospitalized with pneumonia were not necessarily at a higher risk of death.…”

“…They frequently coexist [3]; pneumonia is the most common cause of death in patients with dementia [4,5], and dementia is a well-recognized risk factor for community acquired pneumonia [6] and aspiration pneumonia [7] in the elderly. Pneumonia is also reportedly associated with poor long-term prognosis in patients with dementia [8,9]. Several studies have assessed the association between independent comorbidities with in-hospital mortality [10][11][12] in patients with pneumonia; however, the influence of dementia is not completely understood.…”

Neurovascular dysfunction and neurodegeneration in dementia and Alzheimer's disease

“…Interestingly, HSV-1 infections are found more often in APOE4 carriers [164], which have increased BBB permeability [30]. Additionally, dementia patients have a two-fold increased mortality rate from pneumonia [165], and pneumonia patients have elevated MMP-9 levels in their serum [166], which is known to be linked to BBB breakdown [29]. Furthermore, poor oral hygiene, oral inflammation and tooth loss worsen with age and are risk factors for AD [167].…”

Risk of pneumonia associated with incident benzodiazepine use among community-dwelling adults with Alzheimer disease

“…8,30 Pneumonia often leads to admission to hospital, 10 and patients with dementia are at increased risk of death related to pneumonia. 12,13 Although our findings need further research and confirmation, the increased risk of pneumonia should be considered when benzodiazepines and Z-drugs are prescribed to older adults with Alzheimer disease.…”

“…11 Dementia is also a risk factor for pneumonia-related death. 12,13 Thus, it is important to recognize factors that increase the risk of pneumonia. Benzodiazepines are known to induce sedation, and more pronounced sedative effects are noticed among older adults because of pharmacodynamic changes.…”