Related Experiment Video
Updated: May 4, 2026

Assessment of Dependence in Activities of Daily Living Among Older Patients in an Acute Care Unit
Published on: September 30, 2020
Infection hospitalization increases risk of dementia in the elderly
Judith A Tate1, Beth E Snitz, Karina A Alvarez
11Department of Acute and Tertiary Care, School of Nursing, University of Pittsburgh, Pittsburgh, PA. 2Department of Neurology, University of Pittsburgh, Pittsburgh, PA. 3Department of Biostatistics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA. 4National Center for Complementary and Alternative Medicine (NCCAM), National Institutes of Health, Bethesda, MD. 5The Clinical Research, Investigation, and Systems Modeling of Acute Illness Center, University of Pittsburgh, Pittsburgh, PA. 6Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA. 7Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA. 8Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA. 9Department of Epidemiology, School of Public Health, University of Washington, Seattle, WA. 10Section on Gerontology and Geriatric Medicine, Wake Forest School of Medicine, Winston-Salem, NC. 11Department of Biostatistics, University of Washington, Seattle, WA. 12School of Medicine, University of Virginia, Charlottesville, VA.
Objectives:
Severe infections, often requiring ICU admission, have been associated with persistent cognitive dysfunction. Less severe infections are more common and whether they are associated with an increased risk of dementia is unclear. We determined the association of pneumonia hospitalization with risk of dementia in well-functioning older adults.
Design:
Secondary analysis of a randomized multicenter trial to determine the effect of Gingko biloba on incident dementia.
Setting:
Five academic medical centers in the United States.
Subjects:
Healthy community volunteers (n = 3,069) with a median follow-up of 6.1 years.
Interventions:
None.
Measurement And Main Results:
We identified pneumonia hospitalizations using International Classification of Diseases, 9th Edition-Coding Manual codes and validated them in a subset. Less than 3% of pneumonia cases necessitated ICU admission, mechanical ventilation, or vasopressor support. Dementia was adjudicated based on neuropsychological evaluation, neurological examination, and MRI. Two hundred twenty-one participants (7.2%) incurred at least one hospitalization with pneumonia (mean time to pneumonia = 3.5 yr). Of these, dementia was developed in 38 (17%) after pneumonia, with half of these cases occurring 2 years after the pneumonia hospitalization. Hospitalization with pneumonia was associated with increased risk of time to dementia diagnosis (unadjusted hazard ratio = 2.3; CI, 1.6-3.2; p < 0.0001). The association remained significant when adjusted for age, sex, race, study site, education, and baseline mini-mental status examination (hazard ratio = 1.9; CI, 1.4-2.8; p < 0.0001). Results were unchanged when additionally adjusted for smoking, hypertension, diabetes, heart disease, and preinfection functional status. Results were similar using propensity analysis where participants with pneumonia were matched to those without pneumonia based on age, probability of developing pneumonia, and similar trajectories of cognitive and physical function prior to pneumonia (adjusted prevalence rates, 91.7 vs 65 cases per 1,000 person-years; adjusted prevalence rate ratio = 1.6; CI, 1.06-2.7; p = 0.03). Sensitivity analyses showed that the higher risk also occurred among those hospitalized with other infections.
Conclusion:
Hospitalization with pneumonia is associated with increased risk of dementia.
More Related Videos
Related Concept Videos
Development of Human Microbiota
Dementia l: Introduction
Alzheimer Disease l: Introduction
Dementia
The progression of dementia is generally gradual....
Healthcare Associated Infections II: Preventive Measures
The best practices for preventing healthcare-associated infections include hand hygiene, patient risk...
Factors Affecting the Risk of Infection
The integrity and count of the white blood cells help the body resist pathogens and fight infection. When impaired, it reduces the body's resistance to pathogens. The acidic pH levels of the gastrointestinal, genitourinary tracts, and skin...

