kitchen table math, the sequel: Arithmetic for the ages (Ebola v. influenza edition)

Sunday, October 19, 2014

Arithmetic for the ages (Ebola v. influenza edition)

Ed and I were chatting about op-eds urging people to forget about Ebola & go get their flu shots, when it occurred to me to wonder how many people actually die of the flu. (Ed had just read an article estimating that with early diagnosis & full supportive care in a Western hospital, the fatality rate for Ebola would be somewhere in the vicinity of 10%.)

Turns out practically nobody dies from the flu:
"Over a period of 30 years, between 1976 and 2006, estimates of flu-associated deaths in the United States range from a low of about 3,000 to a high of about 49,000 people."

Key Facts about Influenza (Flu) & Flu Vaccine
Somebody should check my calculator skills, but using 250,000,000 as the figure for U.S. population I get:

Estimated number of flu fatalities per year: 100 to 1,633
Estimated percent flu fatalities per year: 0.00004% to 0.0007%

I don't know whether the CDC publishes an estimate for how much these numbers were affected by flu vaccine. I'm guessing: not much, seeing as how flu shots aren't particularly effective.

Does anyone know the history of flu shots & the flu shot campaign?

Is there a good reason the entire population is urged to get a flu shot every year?

What am I missing?

For the record, I stopped getting flu shots a few years ago. It's not at all convenient for me to get a flu shot (I used to have to persuade the kids' pediatrician to give me a flu shot, too); the shots hurt; and I always get slightly sick from the shot.

Plus I usually ended up with a wicked case of the flu anyway.

I haven't had the flu since I stopped getting the shot.

Either I'm free-riding on other people's flu shots, or I'm just not getting the flu.

UPDATE: CDC writing lesson & expert raters using holistic scoring rubrics


Courtney Ostaff said...

Getting a flu shot is not about you. It's about the suppressing the spread to vulnerable populations with suppressed immune systems.

Children younger than 5, but especially children younger than 2 years old
Adults 65 years of age and older
Pregnant women

A recent study* showed that flu vaccine reduced children’s risk of flu-related pediatric intensive care unit (PICU) admission by 74% during flu seasons from 2010-2012.
One study showed that flu vaccination was associated with a 71% reduction in flu-related hospitalizations among adults of all ages and a 77% reduction among adults 50 years of age and older during the 2011-2012 flu season.
Flu vaccination is an important preventive tool for people with chronic health conditions. Vaccination was associated with lower rates of some cardiac events among people with heart disease, especially among those who had had a cardiac event in the past year. Flu vaccination also has been shown to be associated with reduced hospitalizations among people with diabetes (79%) and chronic lung disease (52%).
Vaccination helps protect women during pregnancy and their babies for up to 6 months after they are born. One study showed that giving flu vaccine to pregnant women was 92% effective in preventing hospitalization of infants for flu.
Other studies have shown that vaccination can reduce the risk of flu-related hospitalizations in older adults. A study that looked at flu vaccine effectiveness over the course of three flu seasons estimated that flu vaccination lowered the risk of hospitalizations by 61% in people 50 years of age and older.

Can a flu shot give you the flu?

No, a flu shot cannot cause flu illness. Flu vaccines that are administered with a needle are currently made in two ways: the vaccine is made either with a) flu vaccine viruses that have been 'inactivated' and are therefore not infectious, or b) with no flu vaccine viruses at all (which is the case for recombinant influenza vaccine). The most common side effects from the influenza shot are soreness, redness, tenderness or swelling where the shot was given. Low-grade fever, headache and muscle aches also may occur.

In randomized, blinded studies, where some people get inactivated flu shots and others get salt-water shots, the only differences in symptoms was increased soreness in the arm and redness at the injection site among people who got the flu shot. There were no differences in terms of body aches, fever, cough, runny nose or sore throat.

Crimson Wife said...

Those are ANNUAL numbers. Several thousand Americans each year die from complications of the flu, typically pneumonia. In winter months, it's common to see about 8% of all deaths coming from flu complications.

westkymom said...

i wonder how many people would get the flu if the people with the flu would either stay home until they are no longer contagious (so that would mean no trips to the store for whatever reason) or people would actually get on board with the whole handwashing thing (how many times do you use a public restroom and someone leaves without so much as a glance toward the sink, and don't get me started on school children and the lack of handwashing in schools!)? your next post should be about the tamiflu medication and why it probably won't help you get over the flu!

Anonymous said...

As Crimson Wife said, I think these may be annual numbers (with very poor phrasing). Another government site claims "Influenza and Pneumonia: 53,826" under causes of death. I assume that the two are considered to be related (eg, the flu caused the pnemonia).

-Mark Roulo

Anonymous said...

The numbers are certainly annual:

"The number of seasonal influenza-associated (i.e., seasonal flu-related) deaths varies from year to year because flu seasons are unpredictable and often fluctuate in length and severity. Therefore, a single estimate cannot be used to summarize influenza-associated deaths. Instead, a range of estimated deaths is a better way to represent the variability and unpredictability of flu. An August 27, 2010 MMWR report entitled “Thompson MG et al. Updated Estimates of Mortality Associated with Seasonal Influenza through the 2006-2007 Influenza Season. MMWR 2010; 59(33): 1057-1062.," provides updated estimates of the range of flu-associated deaths that occurred in the United States during the three decades prior to 2007. CDC estimates that from the 1976-1977 season to the 2006-2007 flu season, flu-associated deaths ranged from a low of about 3,000 to a high of about 49,000 people..."

-Mark Roulo

703 said...

We no longer do flu shots here. One teen became very ill with the flu right after he rec'd the flu shot each year, three years in a row. Never had the flu before, and never after. The last time, his ped wouldn't see him, and sent him to a flu clinic run by the practice. I had to don protective apparel. The dr. on duty said son was the sickest patient of the entire week..and none of the other patients waiting looked like they had more than a cold. So, now we've had a three years with no flu shot and no flu. I figure I'm better off not being in a waiting room full of sick people or shopping while people who don't cover while they cough are out.