Elderly People With Influenza and Dementia More Likely to Die
By Janis C. Kelly
Medscape Medical News
November 10, 2009 — Elderly individuals are less likely than younger people to contract influenza, but those with dementia are 50% more likely to die from the disease compared with their cognitively intact counterparts, new research suggests.
In addition, older individuals with dementia are at even greater risk if they live in a rural or remote area.
"In light of national preparedness for novel influenza strains, our results have important implications for influenza vaccinations, testing, and treatment policies and practices that target the growing fraction of US elderly with cognitive impairment," lead author Elena Naumova, PhD, professor of public health and community medicine at Tufts University School of Medicine in Boston, Massachusetts, told Medscape Psychiatry.
The 3-pronged study, which analyzed geographic and demographic patterns of pneumonia and influenza and the relationship between these diseases and healthcare accessibility, is published online October?26 in the Journal of the American Geriatrics Society.
Special Attention for Rural Residents
The observational study used historical medial claims data from the Centers for Medicare and Medicaid Services supplemented with information from other large national databases to conduct a retrospective analysis of more than 6?million cases of pneumonia and influenza between 1998 and 2002.
The researchers analyzed county-specific outcomes, length of hospital stay, and percentage of deaths in hospital, as well as associations with county-specific elderly population density, percentage of nursing home residents, median household income, and rurality index.
The study showed that rural and poor counties had the highest rates of pneumonia and influenza. In addition, although elderly patients with dementia had a lower frequency of influenza diagnosis, they had a mortality rate that was 1.5-fold higher than the national average.
"Special attention should be paid to the elderly living in rural communities. Clear guidelines for hospitalizations in remote areas have to be developed and reinforced. Policymakers and healthcare administrators should carefully plan appropriate services for patients with cognitive impairment," Dr. Naumova said.
In view of the elderly population's greater vulnerability to infections such as pneumonia and influenza and susceptibility to complications, Dr. Naumova said that the findings were not entirely surprising. However, she added, the data point to some important problems with the current system.
Rapid Diagnosis "Critical"
Rapid diagnosis and treatment of influenza in elderly people is critical because delays can trigger the development of secondary pneumonia, she said. Elderly people with dementia are particularly vulnerable to complications from common respiratory infections because of difficulties in communicating their symptoms, poor oral hygiene, and swallowing problems. Socioeconomic factors may also delay prompt access to healthcare and indirectly increase the risk of complications, said Dr. Naumova.
Although a high proportion of patients with dementia are institutionalized and under supervision of healthcare personnel, rates of influenza vaccination and testing in dementia patients are unknown, she added.
"Limited access to specialized healthcare services can delay diagnosis and treatment of the flu, causing it to progress to pneumonia, the fifth leading cause of death among the elderly. This study has helped us identify this vulnerable population, and now further study is needed to confirm the findings and assess the testing and vaccination policies for older patients with dementia," she said.
Findings "Preliminary"
Commenting on the study's findings, William Thies, PhD, chief medical and scientific officer of the Alzheimer's Association, cautioned that although the findings are "interesting and complex" they are "preliminary."
"The fact that fewer people with dementia get the flu may simply reflect their restricted levels of social contact. There doesn't seem to be sufficient information on this issue to suggest a clarion call for change in health practices. We would need a significant amount of additional research to truly understand the complicated relationships between flu, pneumonia, and rural medical care delivery," he told Medscape Psychiatry.
Dr. Naumova and Dr. Thies have disclosed no relevant financial relationships. The study was funded by the National Institute of Allergy and Infectious Diseases and the National Institute of Environmental Health Sciences.
J Am Geriatr Soc. Published online October 26, 2009.
