Flu shot does not cut risk of death in elderly

[Hannah Bell]

Fri Aug 29, 2008

NEW YORK (Reuters Health) - While influenza vaccination does provide protection against catching the flu, it does not have a major impact on death in the elderly, contrary to what some studies have suggested, a new study suggests.

In prior studies, an impressive 50 percent reduction in death from any cause had been noted in elderly people who got a flu shot, but some researchers were skeptical of this degree of benefit, suggesting that it may have been the result of the "healthy user effect." The new study supports this line of thinking.

The study included more than 700 elderly people, half of whom had gotten a flu shot and half of whom had not. After controlling for a variety of factors that were largely not considered or simply not available in previous studies, the researchers concluded that any death benefit "if present at all, was very small and statistically non-significant and may simply be a healthy-user artifact that they were unable to identify."

"Over the last two decades in the United Sates, even while (flu) vaccination rates among the elderly have increased from 15 to 65 percent, there has been no commensurate decrease in hospital admissions or all-cause mortality," added co-investigator Dr. Dean T. Eurich, who is also with the University of Alberta.

http://www.reuters.com/article/healthNews/idUSHAR96014920080829?feedType=RSS&feedName=healthNews


A Shot of Fear
Flu Death Risk Often Exaggerated; So Is Benefit of Vaccine

By Steven Woloshin, Lisa M. Schwartz and H. Gilbert Welch
Special to The Washington Post
Tuesday, October 25, 2005; Page HE01

Medical research often becomes news. But sometimes the news is made to appear more definitive and dramatic than the research warrants. This series dissects health news to highlight some common study interpretation problems we see as physician-researchers and show how the research community, medical journals and the media can do better.

For years, the public health community has used fear as one strategy to promote the flu vaccine. A vaccination poster distributed by the U.S. Centers for Disease Control and Prevention (CDC), for example, emphasizes that "36,000 Americans die of flu-related illnesses each year," implying that the vaccine could prevent many of these deaths...

Unfortunately, the evidence on how well the vaccine works to prevent death in the elderly is limited. Few of the existing studies are randomized trials -- considered the gold standard for medical evidence. Instead, most data are from observational studies -- studies in which scientists simply count up outcomes (here, the number of deaths that occur among people who did or did not get the vaccine).

But drawing conclusions about cause and effect from such observations is fraught with problems.

http://www.washingtonpost.com/wp-dyn/content/article/2005/10/22/AR2005102200042.html

[still_one]

1. The flu vaccine is to help prevent catching the flu, not death from other causes

Even by their own words:

While influenza vaccination does provide protection against catching the flu,

gee, if you prevent someone getting the flu, just maybe you might prevent someone from getting pneumonia as a result of the flu

This sounds like the bullshit nonesense they were saying that PSAs or PAP smears do not curtail death rates from prostate cancer or cervical cancer

Sounds to me like HMOs trying to reduce costs again

[bananas]

2. No, the flu vaccine is supposed to reduce secondary infections.

That's the rumor.
Does it?

[TZ]

3. You know what the flu vaccine DOES do?

It helps prevent people with autoimmune issues from getting the flu and GETTING very sick. It also keeps people from days on end of misery and from passing it on. AND from very young children getting sick. Nope flu shot doesn't do anything. For every person who doesn't get vaccinated they make GROUPS of people sick. Some seriously sick. But I guess, screw everyone else, as long as I'm healthy it doesn't matter...:sarcasm:

[Fire_Medic_Dave]

4. They seem to refute themselves.

From the first link, "Flu vaccination was, in fact, associated with reduced mortality of about 50 percent (8 percent vs. 15 percent mortality in the vaccinated and unvaccinated groups, respectively), and this finding did not change after accounting for age, gender, or co-existing illnesses." On a side note, I find it odd that none of the 700 people in this study developed autism, jk.

David

[Jim__]

5. Did you read the very next paragraph?

However, after adjusting for other potential confounders, including functional and socioeconomic status, the mortality reduction was weakened and no longer statistically significant.

That clarifies the paragraph that you cited, and they no longer seem to refute themselves.

[Fire_Medic_Dave]

6. So we have clear, concise facts and we negate them with potential confounders.

So if everyone gets a flu shot then we cut flu related mortality by about 50% but if we obscure the facts with potential problems that are difficult to quantify then we aren't sure what percentage of people the flu shot saves. Sounds like it's better if everyone gets a flu shot.

David

[Jim__]

7. According to this study, the facts that you are citing are clear, concise, and may well be ...

... incorrect.

But, to make my previous point clear, the article is not self-refuting.

[Fire_Medic_Dave]

8. Don't think so.

The facts are what they are, in this case Flu vaccination was, in fact, associated with reduced mortality of about 50 percent (8 percent vs. 15 percent mortality in the vaccinated and unvaccinated groups, respectively), and this finding did not change after accounting for age, gender, or co-existing illnesses. The conclusion drawn from those facts can be correct or incorrect but the facts remain the same. My main problem is with the dumbass title of this article, a tiny study of 700 people and they print a title that comes across as fact, "Flu shot does not cut risk of death in elderly" it's assinine. The study shows factually something very different. That would actually make a good story, what are the potential confounders? Do people with less access to health care die at a higher rate from the flu and flu related illnesses regardless of vaccination status? That's an interesting way to go. That seems to be what is happening but the reporting is so bad that I can't tell. If that actually got reported maybe we could come up with a protocol change that could decrease those deaths, maybe the government would be forced to provide better access to health care. Instead all we get is an anti-vaccine rant.

David

[Jim__]

9. I'm not sure what "anti-vaccine" rant you're talking about.

The story in Reuters, the story whose headline you cite and from which you cited a paragraph, does not seem at all anti-vaccine to me. The story merely reports the conclusions of a new study. The study claims that the 50% decrease in death rates that is correlated with getting a flu shot appears not to be an effect of the shot:

"Further, only about 10 percent of winter-time deaths in the United States are attributable to influenza, thus to suggest that the vaccine can reduce 50 percent of deaths from all causes is implausible in our opinion," he added.

...

"Previous studies were likely measuring a benefit not directly attributable to the vaccine itself, but something specific to the individuals who were vaccinated -- a healthy-user benefit or frailty bias," Eurich concluded in a statement.

[Fire_Medic_Dave]

10. "A Shot of Fear" that doesn't strike you as anti-vax.

Not even in the slightest. The other article is probably just horrible reporting.

David

[Jim__]

11. The article, "A Shot of Fear", is not directly related to the study we were discussing.

And, "A Shot of Fear", is a title, not a rant. And, no, the article itself does not appear to be an anti-vaccine rant. I doubt the authors:

Steven Woloshin, Lisa Schwartz and Gilbert Welch are physician-researchers in the VA Outcomes Group in White River Junction, Vt., and faculty members at the Dartmouth Medical School. They conduct regular seminars on how to interpret medical studies. (Seehttp://www.vaoutcomes.org.) The views expressed do not necessarily represent the views of the Department of Veterans Affairs or the United States Government.

are anti-vacine.

The article gives good information on what the exposure is for people who are unable to get the vaccine:

To promote vaccine use, many in the public health community have overstated the risk of flu-related death and the effectiveness of the vaccine in preventing it. While the flu vaccine may have some important benefit (less flu-related illness), we really do not know whether it reduces the risk of death. For younger individuals -- for whom the chance of flu-related death is extremely small -- any death-protection benefit can only be very modest (and it is unlikely we will ever reliably know whether it even exists). However, we do know that the vaccine reduces the risk of being sick and time lost from work. But because the effect is small, individuals will have to judge for themselves whether it's worth the bother.

We are not suggesting that Americans forgo flu vaccines. We simply want to help people make informed decisions.

For many people, getting the vaccine is a reasonable choice. And many may reasonably choose not to get it. (Consequently, the use of flu vaccination rates by Medicare and others to measure health care quality probably does not make sense.)

[Fire_Medic_Dave]

12. We can disagree.

I don't think reporting the annual numbers of flu related deaths as overstating the risks. The public health community not only has a responsibility to the inidividual patient but in fact to "public" health. Flu vaccines are in fact beneficial to overall public health. To reduce the argument to death protection benefit is extremely short sighted. Most people don't bother to read much past the titles and in both cases they seem pretty anti-vax to me. But to each their own.

David

[Jim__]

17. The BMJ agrees with the assessment in the article.

The BMJ calls the 36,000 number of flu-related deaths cited by CDC a misrepresentation:

In a written statement, CDC media relations responded to the diverse statistics: "Typically, influenza causes death when the infection leads to severe medical complications." And as most such cases "are never tested for virus infection...CDC considers these figures to be a very substantial undercounting of the true number of deaths from influenza. Therefore, the CDC uses indirect modelling methods to estimate the number of deaths associated with influenza."

CDC's model calculated an average annual 36 155 deaths from influenza associated underlying respiratory and circulatory causes (JAMA 2003;289: 179-86). Less than a quarter of these (8097) were described as flu or flu associated underlying pneumonia deaths. Thus the much publicised figure of 36 000 is not an estimate of yearly flu deaths, as widely reported in both the lay and scientific press, but an estimate—generated by a model—of flu-associated death.

William Thompson of the CDC's National Immunization Program (NIP), and lead author of the CDC's 2003 JAMA article, explained that "influenza-associated mortality" is "a statistical association between deaths and viral data available." He said that an association does not imply an underlying cause of death: "Based on modelling, we think it's associated. I don't know that we would say that it's the underlying cause of death."

Yet this stance is incompatible with the CDC assertion that the flu kills 36 000 people a year—a misrepresentation that is yet to be publicly corrected.

I've never been able to find a response from the CDC to that article.

[Fire_Medic_Dave]

20. I guess it depends what gets reported to the CDC.

We had 2 cases last year that were thought to be flu related deaths. They did autopsies and found out they were both meningitis. Our health department is pretty careful about what they call flu related deaths. I've always assumed that other people probably weren't that careful and the numbers could be skewed slightly in either direction.

David

[Jim__]

21. The CDC doesn't base it's number on actual reports.

The number is based on a model. Reported flu deaths don't support the number.

[Fire_Medic_Dave]

22. The models are based on actual numbers.

That's all I'm saying. They keep very specific numbers reported from every county health department in every state. Your own article gave those exact numbers of deaths from flu and flu related pneumonia. The models are estimates of flu associated deaths including those from the flu and flu related pneumonia. The CDC's numbers are often wrong though. For instance, they estimate that 90% of adverse reactions from vaccines aren't reported to VAERS. See they are wrong all the time.

David

[mhatrw]

13. Why not read some more about this before commenting?

http://www.medicalnewstoday.com/articles/119947.php

Adjustment for age, sex and comorbidities did not alter the findings, but adjustment for other confounding, such as socioeconomic status, did.

[Fire_Medic_Dave]

14. researchers said the main message was that the elderly should still be vaccinated

Thanks for providing that useful tidbit.

David

[mhatrw]

15. So that everyone can enjoy the one statistically significant benefit, that of annually enriching

the coffers of flu vaccine producers.

[Fire_Medic_Dave]

16. So YOU disagree with the article that YOU posted a link to.

That's some funny stuff right there. How about YOU do a little more reading next time?

David

[mhatrw]

18. I disagree that the default position should be taking vaccines even

if they don't show a statistically significant benefit.

But that's just me. You are free to shoot up all you wish.

[Fire_Medic_Dave]

19. Please show me where the article said that the flu vaccine shows no significant benefit.

Sorry I like to deal in facts, but hey that's just me. Feel free to ignore the facts all you wish.

David

[mhatrw]

23. When the vaccinated and non-vaccinated groups were adjusted for confounding factors

the difference in relative risk of death was not statistically significant.

[Fire_Medic_Dave]

24. Your claim didn't concern relative risk of death, you claimed there was no significant benefit.

I think I'll take the advice from the doctor in your link instead of you. He seems to know a little bit more about what's going on.

David