www.washingtonpost.com
 
 
 NOTES FROM HILARY: The article on website has graphs that
 wont copy over to this post - might wanna check it out. Also, this
 article is written by Physician researchers who teach courses on how
 to effectively analyze research results & studies. And, here are some
 key pieces of data from this article:
 
 For people younger than 65 (including children), the chance of a flu-related
 death is much smaller -- about one in 100,000.
 

Of course, the flu shot may have benefits besides reducing the chance of death. Many may get flu shots simply to avoid getting sick. The Cochrane Collaboration identified more than 20 randomized trials addressing this question. The overall chance of developing "clinical" flu (we'll explain in a minute) was 19 percent in those chosen, again by chance, to receive the recommended flu vaccine vs. 23 percent in the control groups.

The careful reader may notice that these percentages are substantially higher than those reported for the elderly. (See "How Well Does the Vaccine Work in the Elderly?") This is because clinical flu is defined as a set of non-specific symptoms including fever, cough and muscle aches -- symptoms shared by many non-flu illnesses like the common cold. These non-flu illnesses may be especially common in younger adults because of their exposure to other people, particularly children. To try to isolate the effect of the vaccine, scientists sometimes use laboratory tests to confirm the activity of flu virus in the blood. Using this measure, the chance of flu in the vaccine group is 2 percent vs. 7 percent in the control group.

Happy reading!

----------------------------------
 
 http://tinyurl.com/ddjxk

 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
 

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.
 
 When it became aware of the vaccine shortage last October, the federal
 government changed course and tried to reassure Americans that going
 without a shot was no big deal. "We all need to take a deep breath.
 This is not an emergency," CDC director Julie Gerberding advised the
 public.
 
 Instead of urging vaccination for everyone age 50 and older, as they
 had been doing, government officials recommended shots only for people
 65 and older, and those in selected high risk groups. The public's
 response was predictable: People were upset and confused. Our local
 television news played a story in which a pharmacist was called "a
 murderer" when his vaccine supply ran out. Ironically, the crisis
 mentality led some to engage in behaviors that probably increased
 their risk. Frail elderly people, some with oxygen tanks, stood in
 long lines in the cold, waiting for the vaccine. Others crowded
 clinics and doctors' offices, increasing their chance of exposure to
 flu and other infectious agents.
 
 With uncertainties about this year's vaccine supply, the CDC again
 recommended that highest-risk people get priority for flu shots, at
 least until late October. But last year's flu season may have left
 people confused about essential points: Just how risky is the flu? And
 just how effective is the vaccine? The answers to these questions may
 surprise readers.
 
 How Risky Is the Flu?
 
 First, a caveat: The risk calculations we analyze here describe
 typical flu seasons only. We don't consider here what the picture
 would be in the event of a deadly flu pandemic -- a worldwide outbreak
 of a new, highly virulent flu strain, the potential for which has
 recently drawn considerable media attention. No one really knows how
 likely such an outbreak is, but the risk profile would certainly
 change. A pandemic is a fundamentally different situation: The risk of
 death would be substantially higher, and untested strategies
 (including new treatments, quarantine and a new vaccine) would need to
 be implemented rapidly.
 
 We deal here with what is known about typical flu seasons, based on
 data that form the basis for the federal government's flu-risk figures.
 
 By choosing to highlight the annual number of flu deaths, the CDC
 employed an attention-grabbing tactic often used by public health and
 disease advocacy groups. It's a tactic readers should be inoculated
 against if they want a clear picture of the risks they face. (See
 "Research Basics: Understanding How Big a Risk Is," right.)
 
 In fact, it is very difficult to know how many people die from any
 given disease because there is often much uncertainty in determining
 the cause of death. This is particularly true for the flu. That's
 because it shares symptoms with so many other diseases, and because
 people most likely to die a flu-related death are also at high risk
 for many other causes of death.
 
 Flu deaths are probably undercounted because doctors do not routinely
 test for the flu, and because some deaths that should be attributed to
 the flu are given other diagnoses. For example, someone who dies from
 a heart attack because they are debilitated by the flu might not get
 counted as a flu death. Some overcounting of flu deaths also occurs:
 Clearly not all winter pneumonia deaths are caused by the flu.
 
 According to the CDC, 90 percent of flu-related deaths occur among
 people age 65 years and older. Based on this information and the age
 distribution of the population, the chance of a flu-related death for
 people in that age group is about one in 1,000. Another way of saying
 this is that the chance of not dying from flu for those 65 and older
 is about 999 out of 1,000. (For context, the chance of a flu-related
 death is slightly lower than the chance of dying from a fall or other
 accident.)
 
 For people younger than 65 (including children), the chance of a
 flu-related death is much smaller -- about one in 100,000. Of course,
 adults and children might be concerned about flu-related problems
 besides death, such as being hospitalized or just suffering with
 unpleasant symptoms (typically three to seven days of fever, muscle
 aches, headache, weakness, dry cough and runny nose). As you might
 guess, counting the number of flu-related hospitalizations or the
 number of people experiencing symptoms from the flu is even more
 difficult than counting flu deaths.
 How Good Is the Vaccine?
 
 Getting a shot does not guarantee you will not get sick from the flu
 or die from it. Recently, the Cochrane Collaboration, an international
 group that evaluates the evidence for various medical interventions,
 reviewed the medical literature on the effectiveness of the flu
 vaccine in preventing death.
 
 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.
 
 For example, a 2003 study published in the New England Journal of
 Medicine observed that the flu vaccine was associated with a 50
 percent reduction in the overall death rate (that is, death from heart
 disease, stroke, cancer and all other causes combined). To attribute
 an effect of this magnitude solely to the flu vaccine is ludicrous:
 Flu-related deaths make up less than 2 percent of all deaths. If the
 claim were accurate, the vaccine's power would dwarf that of any other
 medical intervention. There is, however, a much more likely
 explanation: People who choose to get a flu shot are much healthier --
 and therefore already at much lower risk of death -- than people who
 do not.
 
 Only five randomized trials have examined the effectiveness of the flu
 vaccine. In these studies, patients were randomly assigned -- a
 selection technique equivalent to the flip of a coin -- to get either
 a flu vaccine or a placebo injection. But none of these studies looked
 at whether the vaccine prevents death. Instead, the scientists
 measured who developed a flu-like illness. For a summary of the
 findings of these studies, see "How Well Does the Vaccine Work in the
 Elderly?" below.
 
 In the absence of good randomized trial data, it is still possible to
 gauge the effectiveness of vaccination by looking at time trends in
 flu vaccine rates compared with flu-related deaths in the elderly. As
 more people get vaccinated, you would expect the flu-related death
 rate to decline -- if the vaccine is effective. But, as the graph
 below, titled "A Windening Gap," shows, despite a dramatic increase in
 vaccination among the elderly, deaths from the flu and pneumonia have
 hardly budged. (The calculations have taken into account the aging of
 the population.)
 
 For younger adults, flu-related death is so rare that it has not been
 reliably studied: Doing so would require a trial of millions of people.
 
 Of course, the flu shot may have benefits besides reducing the chance
 of death. Many may get flu shots simply to avoid getting sick. The
 Cochrane Collaboration identified more than 20 randomized trials
 addressing this question. The overall chance of developing "clinical"
 flu (we'll explain in a minute) was 19 percent in those chosen, again
 by chance, to receive the recommended flu vaccine vs. 23 percent in
 the control groups.
 
 The careful reader may notice that these percentages are substantially
 higher than those reported for the elderly. (See "How Well Does the
 Vaccine Work in the Elderly?") This is because clinical flu is defined
 as a set of non-specific symptoms including fever, cough and muscle
 aches -- symptoms shared by many non-flu illnesses like the common
 cold. These non-flu illnesses may be especially common in younger
 adults because of their exposure to other people, particularly
 children. To try to isolate the effect of the vaccine, scientists
 sometimes use laboratory tests to confirm the activity of flu virus in
 the blood. Using this measure, the chance of flu in the vaccine group
 is 2 percent vs. 7 percent in the control group.
 
 Studies have also measured another outcome: how vaccination affects
 days lost from work. On average, there are about 0.16 fewer days lost
 from work per person vaccinated. Another way of saying this is that
 about 5 percent of those vaccinated avoid missing about three days of
 work because of the flu. (That is, 0.16 days divided by the 5 percent
 who benefited from vaccination equals 3.2 days.) The other 95 percent
 vaccinated got no benefit.
 Take-Home Messages
 
 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.)
 
 Regardless, public health officials should not exaggerate risks or
 benefits to promote vaccination. Exaggeration carries a price: Not
 only do some people get scared and engage in behaviors that increase
 their risk (like waiting in a crowded clinic for a flu shot). They may
 also grow cynical and end up ignoring health messages that really matter.
 
 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.
 
 To respond to this article, send e-mail to health@washpost.com.
 © 2005 The Washington Post Company