Mild, Moderate, Severe OSA -- Bogus Classifications?

I was just reading an article that said that mild OSA should not be treated. Technically, my sleep apnea is mild. I think my AHI was something like 13 at the diagnostic study. My O2 dropped into the 70's for a long period of time.

Before CPAP, trying to get me to wake up in the morning was harder than raising the dead. I am so much better with treatment, by the way. Clearly, CPAP therapy is making a huge difference for me.

I suspect there may be some people with moderate or even severe OSA who don't feel as terrible as I did. I'm not saying they don't have a serious problem, but it seems that how severe your symptoms are may or may not be related to the AHI number you have.


Also, saying that 0 to 5 is normal, 5 to 15 is mild, 15 to 30 is moderate, and over 30 is severe is just a little to "round" to be convincing to me. Somebody just divided up the numbers for convenience.


Ever wonder why there are so many round numbers in medicine? "Fasting blood glucose should be below 100." Why is it not 103, or 98? "Cholesterol should be below 200." Why is the number not 192? Blood pressure should be below 120/80. Well, why not 123/76?

I'll tell you why not. Nobody actually has data to back up those cut-offs. If there is data, then those are not the numbers. Those are the numbers given to doctors because they are easy to remember and probably are close to the actual 2 or 3 sigma number, if they have one.


I think this whole mild/moderate/severe classification is just bogus. If you have symptoms, then your AHI is too high or something else is wrong. It may be that you have too many arousals, or you are not getting enough sleep, but getting your AHI below 5 is not magical. An AHI of 5 may be way too high for some people even if they solve all of the other problems. Indeed, many people here know what it takes for them to feel good, and for most of them, the boundary is NOT 5. It's some other number, possibly even more than 5. Nobody here is a textbook case.

Here's a perfect example: viewtopic.php?p=514947#p514947

Gerald's AHI was less than 5, but he clearly needs treatment. Because of this bogus classification, his insurance would not pay.


The medical community has a problem. They want to practice medicine just by the books and tests alone. Doctors don't wish to rely on clinical skills anymore. I have noticed that the older doctors I see all do extensive physical exams. The younger doctors, with one exception, did very brief physical exams.


If doctors wish to practice medicine this way, it won't be long until we can just do this over the phone, with cheaper doctors in Pakistan or somewhere. Or better yet, an AI program. We won't really need doctors without surgical or other manual skills if this is all they can provide.

And a 15 second apnea counts the same as a 45 second apnea or a 2 minute apnea. How can that be right?

OutaSync wrote:And a 15 second apnea counts the same as a 45 second apnea or a 2 minute apnea. How can that be right?

You're singing my song, OutaSync, and a new verse. Don't get me started on THAT rant.

This seems as good a thread as any for a post I recently submitted about the AHI benchmark---its origins and even a classic AHI debate between two sleep medicine icons:

-SWS wrote:This excerpt from Promise of Sleep describes how Stanford sleep medicine pioneers William Dement and Christian Guilleminault devised an AHI-of-5 as the original apnea/hypopnea clinical cut off in 1973:

William C Dement in [i]PROMISE OF SLEEP[/i] wrote:In 1973 Christian Guilleminault and I proposed the measure that is still used for the clinical definition of sleep apnea and for rating its severity. We called it the Apnea/Hypopnea Index (AHI). Hypopnea is the term we use when the throat doesn't quite close entirely, but air flow is reduced sufficiently to lower oxygen and cause an arousal. The AHI score represents the average number of Apnea and Hypopnea episodes that a patient has during an hour of sleep. We decided that an AHI of 5 should be the lower limit for making a diagnosis of apnea, so a score of less than 5 (breathing stops fewer than 5 times per hour) is considered too low for clinical diagnosis and doesn't require treatment. However treatment may be necessary if a patient has an AHI of 5 to 10 with other signs or symptoms of apnea such as daytime fatigue or high blood pressure. Although not all my colleagues agree, I feel strongly that people with an AHI of 10 to 20 should definitely consider treatment, even if they are not feeling sleepy during the day. In my opinion, anyone with a score over 20 should always be treated - they will soon have a serious, life-threatening problem."

Sleep medicine and Medicare still adhere to Dement's and Guilleminault's AHI-of-5 as clinical cut-off criterion to this day.

Below is a recap of one classic debate between doctors Sullivan and Rapoport, two sleep medicine legends in their own right. They argue AHI's usefulness as an apnea/hypopnea severity marker in the year 2002: http://www.pulmonaryreviews.com/sep02/p ... Index.html

viewtopic/t55133/viewtopic.php?f=1&t=54 ... rt#p511023

If I were good at remembering where posts are, like Rested Gal is, I would regurgitate my schpill on AHI, measurement error, artificial categorizations of continuous variables, variability in how hypopneas are scored, etc.

Well, here is the link to the article showing that how hypopneas are scored changes the AHI markedly:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2635578/

SleepingUgly wrote:If I were good at remembering where posts are, like Rested Gal is, I would regurgitate my schpill on AHI, measurement error, artificial categorizations of continuous variables, variability in how hypopneas are scored, etc.

This schpill---at least in part?

viewtopic/t55133/search.php?keywords=no ... mit=Search

-and-

search.php?keywords=hypopnea+scoring+ch ... mit=Search

-and-

viewtopic/t55133/search.php?keywords=va ... mit=Search

-and-

viewtopic/t55133/search.php?keywords=ar ... mit=Search

Good posts.

I just spend a fair amount of time reading some very interesting links. One was in a post by SleepingUgly, the thread of that post being linked by -SWS here, I think.


One of the things I'm most curious about is the need for categories--mild, moderate, severe. How does your severity ever affect your treatment choices? Does the way titration is done change? Does having severe mean the doctor will recommend a treatment that he would not recommend for mild? What, exactly, is the helpfulness of that?


I think it would be better just to have a diagnosis of "Sleep Disordered Breathing" (or not) and then figure out which machine and pressure settings you need via titration.

It's a financial decision, needed for convincing an insurance company, or for that matter a patient, to pay for the therapy.

Classifications are arbitrary cognitive constructs that help human beings select a course of action. When a doctor has to decide how use her or his limited resources, classifications help. When the resources are less limited, the classification changes -- vide the push to change the cholesterol levesl for a giving statins, or the arbitrary changes in the definition of how much of a BMI is defined as a "overweight" vs. "obese".

Sleep mecidine still has limited resources. When you're a sleep doctor, and have 10 patients waiting in your waiting room, and a 6 AHI patient refuses therapy, you will spend far less time convincing him or her the therapy is necessary than you will with a 30 AHI patient. OTO, a 5 AHI patient will have a tough time convincing the insurance company to pay for his or her therapy -- because the insurance company is doing probability calculations, and wants to limit its expenses based on probabilities.

There are many type of proton pump inhibiting medication. Different folks respond differently to different meds -- nobody tries to classify who will respond better to which med, because it is cheaper to try one type and the other. Or look at how many people are given medications that will "make them sleep better" without a diagnosis, and without trying other kinds of therapy.

OTO, when you have to know which kind of antibioticum will kill a germ, you do a germ culture in the lab, for that specific germ culture from one specific patient, because you can't afford trial and error in that.

Classifications also creep in when you're trying to do preventive medicine and are public health considerations guide you -- if you want to prevent "full blown symptomatic with harm done to body organs" conditions, you also start asking about where in the scale you start giving preventive treatments. Can you avoid a stroke? Can you avoid a heart attack? Can you avoid diabetes?

Probability is always irrelevant to the single case. As a matter of fact, in the part of statistics that describes populations, the single case has a probability of 0.

Classifications are a tool. Like any other tool, they can be put to good use -- or be used at the wrong time, in the wrong context. A hammer isn't of much use when you're trying to prune a rose bush.

Public health thinking in aggregates has made some doctors forget that the they are attempting to heal, or improve the quality of life of the unique individual sitting before them.

ozij wrote:Classifications are arbitrary cognitive constructs that help human beings select a course of action.

But in all of the examples you gave, the AHI alone was used to discriminate between patients. I'm still trying to figure out where mild/moderate/severe is of any help to a patient.

One thing that is sort of interesting is how many people have bought into the classification thing. "Ooooh, you have severe OSA." Doesn't matter. We've seen plenty of people on this board with mild who feel like death warmed over. I'm sure lots of those with "mild" have a more miserable time than some with "severe," so why, as board members, do we get into the classifications ourselves?

LoQ wrote:But in all of the examples you gave, the AHI alone was used to discriminate between patients. I'm still trying to figure out where mild/moderate/severe is of any help to a patient.

Is "high BP" of any "help to a patient"? I maintain it is, if it convinces an asymptomatic patient to be conscientious in taking measures to lower it. And if "Severe OSA" means a doctor will spend more time trying to convince a reluctant patient to use CPAP, then that distinction is of great value to the patient. Or to the person who comes to this forum saying "I have and AHI of 30, should I trust that XXXX doctor and start doing this therapy?"

If you feel like death warmed over, and your AHI is low, (me too) by all means invest all you can in this therapy. I will agree with you with any bad thing you want to say about a system that makes you pay for that therapy out of pocket. And I will join you in protesting against a system that focuses only on breathing interruptions of a certain kind (apnea and hypopnea) and ignores the other kind: Respiratory Effort Related Arousals that destroy your sleep.

If a person is symptomatic, and doesn't fit an arbitrary criterion for therapy, the criterion is useless to the patient.


No reason that we should not use those distinction on the forum as well to convince people to use CPAP.
O.

ozij wrote:It's a financial decision, needed for convincing an insurance company, or for that matter a patient, to pay for the therapy.

Exactly.

ozij wrote:Public health thinking in aggregates has made some doctors forget that the they are attempting to heal, or improve the quality of life of the unique individual sitting before them.

Amen!!!

ozij, you wrote a masterpiece on classifications, and you put the "limited resources" issue into perspective. Very interesting reading.

-SWS, thanks for the links. Especially to one of my favorites, Dr. Sullivan's pro/con discussion with Rapoport: "THE APNEA-HYPOPNEA INDEX: USEFUL OR USELESS?"

LoQ, you're spot on, imho:

LoQ wrote:The medical community has a problem. They want to practice medicine just by the books and tests alone. Doctors don't wish to rely on clinical skills anymore.

There's a rather famous sleep doctor -- board certified pulmonologist and board certified in sleep medicine, Dr. Barbara Phillips -- who takes the same view. The view that doctors should use their clinical diagnostic skills -- and some common sense.

One of her catchiest quotes goes something like this... "Some people are such obvious OSA cases (and she wasn't talking about measuring AHI) that even the janitor in a sleep lab could diagnose them." I'd add, and if the janitor could prescribe, he'd pause in his work long enough to write a quick Rx for "CPAP @ 10 cm H2O."

Dr. Phillips gave this Powerpoint presentation at a meeting of the American Lung Association of the Central Coast - November 2004:
"Not Every Patient Needs to go to the Sleep Lab"
http://www.tnlc.com/Lara/laura/osa/Barb ... t_0830.pdf

Dr. Littner wrote, at the end of his piece:
"I conclude that first line treatment of mild obstructive sleep apnea should be medical. Ummmm, ..."should be medical." I was under the impression that CPAP provided a "medical" treatment. He seems to be reserving the word "medical" to mean the less expensive things he mentioned...

1. weight loss
That's easy for people to do, isn't it?


2. positional therapy in patients with supine OSA
Well, hey, let's not limit that to a "don't sleep on your back" recommendation. Better yet, and equally cheap, doctors could instruct all the mild/moderate-when-supine cases to sleep for the rest of their lives almost upright in a recliner.

3. nasal corticosteroids in patients with allergic rhinitis Grrrrrreat idea! Open up those troublesome nasal passages and let the tongue/soft palate do ...whatever. After all, we're talkin' about people who have only mild/moderate sleep apnea. Surely the mild/moderate AHI'ers who happen to have allergic rhinitis couldn't possibly have something else, too, could they? Surely they wouldn't have BOTH allergic rhinitis AND something untoward happening farther south in the airway... like somewhere down around the vicinity of the back of the tongue. Right?

Littner wound up with a bold statement:
"CPAP and other modalities such as a dental appliance or surgery should be reserved for failed treatment in highly selected cases." Ohhhhkayyyyy.

"should be reserved", eh? As in "denied", right? Denied to mild/moderate OSA cases...at least until they've failed at trying to lose weight, failed at trying to sleep in position other than the way they find most comfortable, or failed at keeping a collapsing throat open by shooting a spray up the snoot.

I would never wish mild or moderate OSA on someone... but...

Anyone got a voodoo doll I could borrow?

That's the problem - it's always about money with medicine. It's gotten a lot worse in the last 20 years too. These people use statistics over and over again. Well, I studied statistics too - and the bottom line is that statistics can be used to prove almost anything. It just depends on how you set up your study.

I am case in point - I was kicked around by sleep doctors 15 years ago who couldn't agree whether I had apnea or not. They said I snored a lot but they just didn't know. I didn't need 2 sleep tests to know that - my wife could have told you. What did they learn from 2 sleep tests? Obviously nothing. I got a CPAP machine back then because I was financially OK and could afford it. I used it on and off for a year and it went away to the closet.

Only recently did I realize that things were getting worse symptomatically - perhaps not lethal, but enough to make my life more difficult. I went to a local sleep clinic and had an ambulatory sleep test (i never could sleep in those labs anyway!). My AHI came out to 13.4. What do I do now? According to the "profiles" I am not a definite case to be treated. But I snore so badly the dogs run away (about 12 snores per minute!). Well, I could afford a machine - so I bought one myself. The insurance industry says that I am not bad enough to need treatment. I could wait until it got worse, or deal with it before it became a problem that was serious. My doctor would not commit either way. She just wants to earn a living and not fight the establishment. I can't blame her for being pathetic.

So I need to make the choice for treatment because these silly classifications don't mean a thing! I'm one of the lucky ones as I can make that choice. If CPAP doesn't help symptoms, then its money down the drain - but at least I will have tried. Most people don't have that option.

All of medicine is like that. If you have chest pains, you get an EKG. Only if there is a major reason to think that you might get a heart attack do you get a stress test. By that time, you could have irreversible arterial damage. You see it's all about statistics and money and we have very little to say in the matter. The medical community really angers me because many of them really just want to get by within the system. They don't want to think. They are selected not to be able to think. They want to "process" patients all day. So lots of their patients get sicker or die needlessly. My father died from a medical "mistake" - my wife's father did too- as did her mother. I figure it's about 50:50 that I will die from a "mistake" some day also.

Sorry for the preaching, but medically we are really no different from the days when doctors used leeches. We just have better toys and equipment these days. Doctors rarely think. I started years ago as a biotechnology scientist, so I know something about being taught to think. I leaned also how statistics made for bad science and to stay away from it after a point if you wanted other scientists to take you seriously. Cold hard facts and data are all that really matters. The medical community doesn't know very much about what is real or not. They just make rules and follow them.

Jonquiljo - can you explain to me what an ambulatory sleep test is? Doesn't compute! You can't have an ambulatory sleep test!

Other than that, it's not just a financial decision, but as with anything else in life some distinction has to be made to illustrate differences, degrees of severity or mildness because it is practical, it gives an indication of a situation (like the weather!) so that we can come to it at least somewhat prepared to deal with it. People are not machines and of course doctors know lines are overlapped and blurred all over, but it is impractical (especially if you're not one of 100 people in a small village with 3 nice old family doctors and all the time in the world) to have no definition at all in place going in, by which to gauge who's who and what's what. I know that if a doctor sees that you have an AHI of e.g. 6 (one over the so called lower limit of acceptable), he or she will take the whole picture into account, e.g. your age, activity level, diet, physical exam, etc. etc. and steer your treatment accordingly, not just blanketly write you off (or on) based on a one time number, but your medicare (or whatever you want to call it) system is such that the insurance co's demand something to go by when deciding to pay out, so the numbers are used, but a good doctor can find all kinds of ways to get around that if he feels it necessary for your individual condition, possibly tacking on other diagnoses that put you in another category, or initiating treatment outside of Cpap to go along with it. It is not an ideal situation, just like the legal system is not ideal by a long shot, but numbers are used to at least give rough ideas about things just as they are in everything else we do. If you have been classified as not needing help (because you fall in the wrong 'number' category) but you're still feeling terrible, then you're free to pursue things further with other tests, MD's, etc. either until you do end up in the right slot or other ways of helping you are started. Not perfect by a mile, but there's more to it than just numbers or money.

Well the terms used for Home Sleep Tests as opposed to in a Clinical setting Sleep Test are a bit odd.

http://www.mra-medical.com/

"Apneagraph provides an ambulatory sleep study with localisation of obstruction for snoring and Obstructive Sleep Apnea (OSA)"

The big kinda new thing is sleep studies in the comfort of your own home. It is now being accepted by insurance for diagnosis.
However it is not everywhere yet. I had a titration sleep study last fall and when I asked the Insurance company if I could not have an in home Titration with my handy dandy APAP that I use every night, their response was....... "Only if it is medically necessary" Meaning that I could not make it to the sleep lab.
Which was at a very nice Hilton with a nice hot breakfast of whatever I wanted to eat in the AM. So I was forced to use a more expensive sleep titration, because they did not understand it was cheaper and more effective at my own home.

It cost way too much for the insurance, but I had to have a sleep study because I wanted to purchase a new machine and it had been 5 years since my last sleep test. I told the Sleep Doctor that my setting is around 9 but that I am using APAP between 7-11 each night.

After my lovely overnight test, the doc told me "Your setting is 9" He was nice but more suited to the OSA patient who does need the help with their diagnosis and titration.


Sorry for my rant, but I truly wish the insurance companies would get this sorted out so that we pay lower premiums to get the best possible outcome with Sleep Apnea.

Karen