AN statistics: lies, damned lies, & statistics

[HeadCase2]

   Many of us are interested in the statistics of Acoustic Neuroma (AN). How rare is it? How many people have it?  But there seems to be some confusion about interpreting reported statistics. I often see confusion over Incidence Rate and Prevalence.
  The AN Incidence Rate commonly reported is 1 per 100,00 people for the US.  This Incidence Rate is how many
are diagnosed with AN each year.  Prevalence is how many have the condition in a population.  For the US, using a
population of 300,000,000 times the Incidence Rate of 1 per 100,000, means that about 3000 people are
diagnosed with AN each year in the US. 
  To make a rough estimate of the number people in the US that have been diagnosed with AN (the Prevalence of AN in the US),
multiplying the yearly figure (3000) by 20 years (ave life span of 75 minus the ave age of discovery 55)
 equals about 60,000 people.  Admittedly this is a very rough estimate, and only includes those who
have been diagnosed AN.
  What is the Prevalence if we include those who have AN, but have not been diagnosed with it.  One study estimated the
incidental rate of AN (the rate of people who have AN, but the AN was noted as an incidental finding by looking for AN in MRI's performed for other diagnostic purposes) as 2 per 10,000 (see "The Prevalence of "Incidental" Acoustic Neuroma"" at http://archotol.ama-assn.org/cgi/content/abstract/131/3/241 ).  This would give an incidental Prevalence of 60,000 people in the US.  Adding together the diagnosed Prevalence of AN with the incidental Prevalence of AN equals 120,000 people in the US with AN.  :( 

Regards,
 Rob

There are three kinds of lies: lies, damned lies, and statistics.
- Benjamin Disraeli
British politician (1804 - 1881)

[Patti UT]

Headcase,
   Thanks for the stats.  you don't really think someone would lie to us?? LOL   With the number of newbies just on this forum every week, I have felt there must be many more per year than they tell us. Very interesting info to ponder.  Regardless of "how many" I just hope they can find a better way to treat the darn things leaving the post op problems behind.

Patti UT

[Gennysmom]

The thing about statistics, is that you can make numbers essentially look however you want.....that's the beauty and the downfall of the darn thing.  I heard an interesting one the other day....that conjoined twins occur once in every 100,000 live births.  That number looks familiar........hmmm.....don't hear much about conjoined twins, do we? 

I think no matter how we look at the numbers, what they're not saying is that we're not as prevalent as many other disorders/illnesses, and we will most likely never get the research time and investment thrown at other issues.  Do the most good for the most amount of people with the resources you have....we will always be a minority, so I believe we need to continue to be our own best advocates at any opportunity we can. 

[ppearl214]

Some of us have been discussing this lately... seems the ages of those diagnosed are younger, the world of the internet has brought out more info thatn initiallly published.

My goal was to ask about the stats of AN'ers and procedures and outcomes and post-treat prognosis at the Symposium next year in Philly... Trust me... I got my questions all set to ask!  will be curious to see what the professionals say.

Phyl

[HeadCase2]

gennysmom,
 Ã‚ I agree that other more prevalent medical problems will probably get more research investment than AN.  Although I'm amazed at how far AN treatment has come since the 1960s.  Advances in both microsurgical technique and radiosurgical devices have really improved the prognosis for AN.
 One of the reasons I went through this estimate, was just curousity on how rare AN really is in my area.  For example, in a city with a million people, there are probably about 200 people (10 per million per year x 20 years) who have been diagnosed with AN.  Relatively rare to be sure, but not as rare as I had guessed.
 Ã‚ If An was even more rare, perhaps we wouldn't have Skull Base Tumor treatment teams at most tertiary hospitals.  And without those teams, I don't think AN treatmemnt advances would be progressing at the rate they do.  The more doctors working on the problems related to AN the better.  Through their desire to improve outcomes for their patients, and perhaps because of their egos to be the best in the world at what they do, medical science advances and we benefit.
Regards,
 Rob

[Gennysmom]

I agree Rob...the drop in morbidity levels alone are amazing, not just with AN, but lots of other things.  I just think that there's a lot of epherial things we discuss on here that a lot of people talk about their doc's poo-pooing a relationship with the AN, and the lack of continuing support after treatment....OK, it's out, we're done, there should be nothing wrong with you now, with the exception of specific issues like dry eye, balance issues, etc.  I'm not experiencing that at all, my doctors have all been very receptive, but it doesn't seem like that's across the board.  The other thing that I find interesting is that even within "Brain Tumors", we're hardly identified...I belong to ABTA, and every newsletter is about cancerous tumors, which, thankfully, I'm not dealing with, but we're seemingly not on their radar screen either. 

I know there has been talk about trying to get a roundtable team/patient thing going on with new stats at the Syposium this July.  I hope we do.  My doctor made several comments about moving from doing 1-2 surgeries a month, to 1-2 a week, which he is attributing to better diagnostic tools being used.  Maybe.....maybe not.  It makes sense, but so did all the loud concert damage I did in the 80's as why I lost hearing in one ear....boy, was I wrong about that! 

Keep up with analyzing the stats....I think that way too...what I find interesting is that we seem to be a well educated, articulate bunch...is that just because of the computer we use to get here, or is that the slice of population lucky enough to have AN's?

[marjoryb]

Someone should alert Oprah to our plight!

Marjoryb

[Gennysmom]

Actually, I think someone was going to do that hoping that we could get on her favorite things episode!   

[Jim Scott]

Reading statistics eventually gives me a headache but I believe that while Acoustic Neuroma is relatively rare in the 'general population', I also think that with more physician awareness of it and the MRI scan being used more often (sometimes looking for other problems) AN's are going to be discovered sooner (often, in younger folks) and the more common symptoms not so often attributed to other medical problems while the possibility of an AN is overlooked.   

I have to agree that AN patients will likely remain a minority for the foreseeable future and, as such, hardly come close to receiving the money or media attention breast cancer, heart disase, AIDS and other illnesses/diseases routinely get.   Be that as it may, we can still do our part as individuals to advocate for better AN awareness in the medical community and improved treatment, as well as more surgeon training in that particular area of neurosurgery. 


Jim