Featured Research

from universities, journals, and other organizations

Flu Vaccination Impact On Elderly Deaths May Be Over-estimated

Date:
February 23, 2005
Source:
Journal Of The American Medical Association
Summary:
Observational studies which report that influenza vaccination reduces winter mortality risk among the elderly by 50 percent may substantially overestimate the vaccination benefit, according to the February 14 issue of The Archives of Internal Medicine, one of the JAMA/Archives journals.

CHICAGO – Observational studies which report that influenza vaccination reduces winter mortality risk among the elderly by 50 percent may substantially overestimate the vaccination benefit, according to the February 14 issue of The Archives of Internal Medicine, one of the JAMA/Archives journals.

Accurate determination of the impact of influenza on mortality is difficult because the infection is often cleared before the onset of the secondary complications that actually cause a person's death, according to the article. Although influenza vaccination of the elderly in the U.S. has increased from 15 to 20 percent before 1980 to 65 percent in 2001, the authors could find no correlation between this increasing vaccination coverage after 1980 and declining deaths rates in any age group. Observational studies may introduce a systematic bias that leads to a substantial over-estimate of the impact of influenza vaccination on mortality, the authors suggest.

Lone Simonsen, Ph.D., of the National Institute of Allergy and Infectious Diseases, and colleagues, used statistical models that estimate the winter-seasonal all-cause mortality above an estimated baseline to determine influenza-related mortality indirectly. Their model incorporated information on deaths among the elderly from pneumonia and influenza and all other causes from 33 winter seasons from 1968-2001. "Our results, based on national vital statistics, are simply not consistent with the very large mortality benefits reported in observational studies," the authors write. The authors suggest that this disconnect may be explained by a disparity in who is likely to be vaccinated. "Very ill elderly people, whose fragile health would make them highly likely to die over the coming winter months, are less likely to be vaccinated during the autumn vaccination period," they stated.

"Our results have obvious implications for influenza vaccination policy. … The present findings, and those of at least one other study, indicate that the shortage [of influenza vaccine in the 2004-2005 season] will have little impact [on mortality]…," the authors conclude. "Other cohort studies suggest that the shortage will have a tremendous impact on mortality among the elderly. Either way, this vast disconnect between conclusions from different studies must be sorted out."

(Arch Intern Med. 2005; 165:265-272. Available post-embargo at www.archinternmed.com.)

Editor's Note: This study was funded by an Unmet Needs grant from the National Vaccine Program Office, Washington, D.C.


Story Source:

The above story is based on materials provided by Journal Of The American Medical Association. Note: Materials may be edited for content and length.


Cite This Page:

Journal Of The American Medical Association. "Flu Vaccination Impact On Elderly Deaths May Be Over-estimated." ScienceDaily. ScienceDaily, 23 February 2005. <www.sciencedaily.com/releases/2005/02/050218132606.htm>.
Journal Of The American Medical Association. (2005, February 23). Flu Vaccination Impact On Elderly Deaths May Be Over-estimated. ScienceDaily. Retrieved October 22, 2014 from www.sciencedaily.com/releases/2005/02/050218132606.htm
Journal Of The American Medical Association. "Flu Vaccination Impact On Elderly Deaths May Be Over-estimated." ScienceDaily. www.sciencedaily.com/releases/2005/02/050218132606.htm (accessed October 22, 2014).

Share This



More Health & Medicine News

Wednesday, October 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

CDC Revamps Ebola Guidelines After Criticism

CDC Revamps Ebola Guidelines After Criticism

Newsy (Oct. 21, 2014) The Centers for Disease Control and Prevention have issued new protocols for healthcare workers interacting with Ebola patients. Video provided by Newsy
Powered by NewsLook.com
WHO: Ebola Vaccine Trials to Start a in January

WHO: Ebola Vaccine Trials to Start a in January

AP (Oct. 21, 2014) Tens of thousands of doses of experimental Ebola vaccines could be available for "real-world" testing in West Africa as soon as January as long as they are deemed safe in soon to start trials, the World Health Organization said Tuesday. (Oct. 21) Video provided by AP
Powered by NewsLook.com
First-Of-Its-Kind Treatment Gives Man Ability To Walk Again

First-Of-Its-Kind Treatment Gives Man Ability To Walk Again

Newsy (Oct. 21, 2014) A medical team has for the first time given a man the ability to walk again after transplanting cells from his brain onto his severed spinal cord. Video provided by Newsy
Powered by NewsLook.com
CDC Issues New Ebola Guidelines for Health Workers

CDC Issues New Ebola Guidelines for Health Workers

Reuters - US Online Video (Oct. 21, 2014) The U.S. Centers for Disease Control and Prevention has set up new guidelines for health workers taking care of patients infected with Ebola. Linda So reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins