That misleading study rears its head again...

From a link in the Streaming CPAP and Sleep Apnea News:
http://www.emaxhealth.com/46/4802.html


Sleep Apnea and Death Association Point to Need to Examine Treatments

By: Mayo Clinic on Mar 08 2006

The troubling part of this study is that most people in it were already receiving treatment for obstructive sleep apnea, Dr. Somers [Virend Somers, M.D., Ph.D., a Mayo Clinic cardiologist] says. "So is the stroke risk even higher for people not being treated, and how much do patients benefit from treatment?" he asks.


Well, there we have it....the very thing that upset some of us about that study in the first place. The researchers didn't check at all into whether the "treated" people were really being "treated" effectively. Were the people even using their machines? If they had surgery or used dental devices, were PSG's done every year thereafter to see if that treatment was effective?

Some of us were bothered by the fact that not only the press but doctors too would draw the conclusion that regardless of "receiving treatment" (WHAT treatment, if the machine is really just sitting in a closet, unbeknownst to the researchers!!?) people with OSA were more likely to die of heart attack and stroke, anyway. Some people would decide not to bother with CPAP since an oft cited study says that even "treated" people will still be at more risk than non-OSA people.

And now there it is... a statement by a cardiologist associated with the Mayo Clinic commenting that "most people in it were already receiving treatment for obstructive sleep apnea". A flat statement as if it were a given that the treated people were being effectively treated. Sheesh. THE RESEARCHERS WHO DID THAT STUDY DIDN'T EVEN KNOW IF THE "TREATED" PEOPLE WERE REALLY BEING TREATED, yet called them "treated".

Those of us who criticized the way the study was done would put it this way:

The troubling part of this study is that the researchers referred to people as "receiving treatment for obstructive sleep apnea" when the researchers did not even know if the people REALLY were using their CPAP machines at all.

Being given a CPAP machine that ends up in a closet -- or actually using it for every sleeping moment -- are two very different things.

Nov 10, 2005 subject: IMPORTANT New Apnea Study

rested gal wrote:And now there it is... a statement by a cardiologist associated with the Mayo Clinic commenting that "most people in it were already receiving treatment for obstructive sleep apnea". A flat statement as if it were a given that the treated people were being effectively treated. Sheesh. THE RESEARCHERS WHO DID THAT STUDY DIDN'T EVEN KNOW IF THE "TREATED" PEOPLE WERE REALLY BEING TREATED, yet called them "treated".

I think this is way too complicated for me, RG, so help me try to understand just a little bit.

Were all the patients undergoing treatment for OSA?

Was the treatment prescribed according to standard medical protocol?

Were the results statistically processed accurately?

I think maybe the answer to all three questions is yes. (But, correct me if I'm wrong.) If true, then I don't understand what possible issues there could be with any of this. It's better than a lot of reports from the medical field these days. I mean, at least the data doesn't appear to have been tampered with, or deliberately skewed like a number of other medical reports which have made news recently.

Regards,
Bill (Sigh. . . thinking this report is just a small speck at the tip of the iceberg.)

rested gal posts - Were the people even using their machines?

The results of the first study - also referred to as the Canadian Positive Airway Pressure trial - were disappointing because, even though the treatment was carefully applied, it was not sufficiently effective, Dr. Somers says.

I would take it from the second quote that they did check on machines being used. It would be a very ineffective study if they didn't. You would actually have to read how the study was carried out to know for sure because this article sure doesn't allude to that.

Patients with both heart failure and central sleep apnea received either CPAP - a mask worn during sleep that delivers air through the airway - or no treatment to see if CPAP improved survival.

The problem though appears to one where the patients used were already in heart failure and had central sleep apnea problems (maybe heart problems cause central apnea's). Here is a link to that study and a follow up study. PSG's were done on the patients.

Initial Study

Second Study

The study dealing with central apnea isn't the one that concerned me the most. It was the second study -- the one dealing with obstructive sleep apnea -- that was the problem study, imho.

More about the iceberg is in this discussion:
Nov 10, 2005 subject: IMPORTANT New Apnea Study

Darth Vader Look



I am not sure what you are getting at. The second study link you provided shows how CPAP improves the situation for people that had heart failure and CSA. I think we are talking about different studies.

According to the studies there were 2 done. Those were the links that I posted. I did read the second study where it said that PAP treatment seemed to help but a more intensive study was needed to verify this. The study also stated that risk of stroke or heart attack were up to 4 times greater if you had OSA. Maybe we aren't on the same page though so I am not sure.

I was inpressed by of the other studies that was in the footnotes that show that people with Heat failure that also have a breathing disorder like CSR-CSA their transplant-free survival rate was far greater using CPAP than in the control group. That study sort of indicates that is may take up to 34 months for the people with heart failure and CSR-CSA to stabilize the survival rate and becomes a straight line while in the control it continues to go down.
http://circ.ahajournals.org/cgi/content ... 02/1/61/F3


But Rested Gal was trying to make a point that some conclusions were being made that CPAP did not help at all. Check the link that Rested Gal provided and let me know what you think.

Much ado about nothing.

None of the studies being discussed/cited were designed to answer questions about whether CPAP therapy lowers the risk of stroke, mortality, etc. caused by obstructive sleep apnea. This sort of thing is typical of the dustup caused every time a research finding makes it way to the popular media.

Researchers in the health sciences do several kinds of large-scale studies. The Yale study being cited here was designed to see (among other things) whether obstructive sleep apnea is responsible for the strokes and deaths due to strokes. That's an epidemiological study and its concern is with health outcomes of a population in general and identifying the things that contribute to those outcomes. Ideally, they would have been able to account for the actual dose and types of CPAP treatment being used by subjects in the study but since they did not, they simply list CPAP treatment as a possible threat to the validity of their epidemiological conclusions about that population.

Another kind of study is the big, randomized, well-controlled clinical trial. To my knowledge, no such study has been published for CPAP treatment and stroke outcomes. Such a study (if done correctly) would be super-expensive and would really need to continue following people for a decade or longer to get a good accounting of the possible outcomes. Until somebody spends ten years and $10,000,000+ dollars to do a prospective study with valid randomization then any conclusion you see about whether CPAP does or does not ameliorate the risk of stroke attributable to OSA is speculative and not based on science.

Brent Hutto wrote:Much ado about nothing.

None of the studies being discussed/cited were designed to answer questions about whether CPAP therapy lowers the risk of stroke, mortality, etc. caused by obstructive sleep apnea. This sort of thing is typical of the dustup caused every time a research finding makes it way to the popular media. .....

I would agree, but it's also infuriating, isn't it, the media using studies to question the validity of cpap treatment?!

I would think these studies are difficult, and as Brent says, expensive, considering the array of factors to consider and to control in a study. How long had a patient suffered the effects of OSA before starting cpap? How much had their heart suffered before starting cpap therapy? And if they suffered non-fatal strokes or heart attacks while on well-administered cpap therapy, how many of those were less severe thanks to the proper use of cpap therapy? What is the health benefit of starting cpap therapy early vs later? And how many patients on cpap therapy were properly treated for any still on-going conditions that may have affected their heart health? All of these do require longer-term studies.

L.

LDuyer wrote:I would agree, but it's also infuriating, isn't it, the media using studies to question the validity of cpap treatment?!

Very annoying, I'll agree. Whenever I see a research topic I have interest in mentioned in a headline or on the news, I just skip straight to the original published results they're talking about. Then again, I have a lot of practice (too much, believe me) in reading that sort of journal articles plus my job gives me freebie access to a lot of medical journals. The problem is that most people don't have access to the real results and would need help deciphering the lingo even if they did. So the media unfortunately are depended on my millions of people. They ought to do a more responsible job of sticking to the actual conclusions and not making up their own (overstated) interpration. [Rant Mode Off]

All of the factors you mention are important. The trickiest thing is doing randomized prospective study, though. You have to randomly assign people to CPAP or no CPAP and then somehow make sure that they stay under that condition long enough to see the effects develop. A big problem is that it may not be fair to randomize a moderate-to-serious OSA sufferer to the "no CPAP" group for a few years. If the CPAP is going to improve their quality of life almost surely and with little side effect then it may not be ethical to ask someone not to use it so you can do your study.

That kind of thing is why some questions never will be definitively answered.

Brent Hutto wrote:Another kind of study is the big, randomized, well-controlled clinical trial.

Brent, I'd like your take on doing a small trial of CPAP vs APAP. In my field we constantly test things. Some tests are incredibly expensive, but those are almost never done until inexpensive tests have been performed and provided confidence in the expected results.

What I'm thinking is that it would be extremely simple for a sleep lab to randomly assign newly diagnosed patients either a straight CPAP machine or an APAP machine which supports monitoring software (but initially set in CPAP mode), and simply provide those with the APAP machine a list of on-line support groups which they might find useful in helping them through the adjustment phase, and also inform them of the availability of monitoring software if they're interested in that sort of thing. Then, after six months or a year see how compliant both groups are, find out how many have decided to use APAP, and have everyone complete a user satisfaction survey about how satisfied they are with the progress of their therapy.

It strikes me that the cost of this would be next to nothing. Presumably, the sleep lab will routinely monitor the patients at certain intervals anyway. Insurance pays the same amount for either CPAP or APAP, so there's no extra cost to the patients either, unless they happen to decide on their own to opt for monitoring software.

But, maybe I just don't understand the bigger picture.

Regards,
Bill

Other than the mayo trials, that website featured an article in Feb, 06
see below:

http://www.emaxhealth.com/46/4364.html

neverbetter wrote:Other than the mayo trials, that website featured an article in Feb, 06
see below:

http://www.emaxhealth.com/46/4364.html

"Machine Works Best for Treating Sleep Apnea, but Few Prefer It" is the title.
So what, right? Interesting but still pointless, in a sense. Can you imagine what CBS or other networks would do with that topic title? "Down with CPAP" and we as a country let's find something better! Fine, don't we all want it to be different? Wouldn't we all prefer not to be using this thing? Wouldn't the diabetic prefer not to poke their skin every day? Would the cancer victim prefer not to take their radiation or chemo therapy? Would an amputee prefer to have their limb back? The general media would take that article, make a big story of it, and then discourage even more people from getting the life-saving treatment they need. For godsakes, find a better solution before convincing people what they already want to believe, that they don't need cpap therapy.

But on the other hand, let the media do what it does, and fight the misconceptions with campaigns to encourage people to get tested and use cpap if needed. We are very lucky in this country to even have a free-wheeling-although-imperfect media. Consider the alternative. ..... Interesting article. Thanks.


L.

Forget all these stupid studies, there will be one next week which says the complete opposite sponsored by some other drug company. Take your 325mg daily aspirin if you want to lower your risk of stroke or MI and drink plenty of pure non-chlorinated water and if you have OSA use your cpap.

We are told by our doctors you have hypertension and that it is a leading cause of strokes. I've had 2 to date. So far I have yet to find a single study that directly associates or links hypertension with stroke yet doctors tell everyone that is the case.

So your doctor prescribes a medication to lower your hypertension which most likely is some form of a diuretic like lasix, it's purpose is to dehydrate you so you have less water in the blood in essence thickening your blood. Thick blood increases your risk of stroke (complete opposite of what you want). Other side effects of the medication is it takes water stored in your joints where arthritis is now free to attack the joints, oh we have a drug for that one too, think it's called Vioxx.

Oh you already had a stroke, not to worry, we have a drug for that one too, it's called Plavix. What do you mean a study out TODAY from Cleveland Clinic shows PLAVIC DON'T WORK any better than plain aspirin and in some cases actually increases your risk of stroke.

http://www.cbsnews.com/stories/2006/03/ ... 3091.shtml

Now FDA approved Plavix as being safe and effective. I always thought effective meant it worked? I have taken Plavix myself for stroke prevention, spending sometimes over $200 a month for that crap finally giving up on it due to high costs. My 86 year old mother is still doing the same. We need to fire all them quacks in the FDA and start over. FDA is simply a joke and a license to steal money from you.

Untreated OSA: It's sorta like the knee bone connected to the thigh bone thingee, with OSA you don't get any oxygen to the brain, brain tells the heart to beat faster as I need more oxygen, your airway is blocked it can't do that, brain again signals heart to beat faster again. It doesn't know you have OSA otherwise it would do its job and hold your tongue out of your throat

The result is you end up with a very fast heart pulse rate even during the day, faster beating heart is going to lead to hypertension, over years of this happening (remember its 7years of avg where people find they have OSA and start treatment). The lining of your arteries are made up of cells, cells that need water and oxygen to survive just like a plant does. Take away the oxygen (in your blood delivery system) the cells that make up the artery wall lining begin die. When they die they become a lesion, cholesterol lipids then begin sticking to the damaged area as a temporary repair where the platelets aggregate over the lesion for making a more permanent repair. It is when these platelets form together creating a thrombus does risk of stroke/MI go up, should a thrombi (clot) break off the thrombus it is free to travel on to the brain/heart where it lands in a tiny artery in the brain and causes a stroke. This happens more on the pressure side of arterial system above the heart more often than below, it is why stroke risk is greater than MI when it comes to OSA. The MI comes from a diseased heart being overworked by untreated OSA.

I agree about the stoke risk of untreated OSA, had a couple of those myself,
a few years back, but if you want to lessen that risk you have to go to the root cause of it (stopping the lesions to your arterial lining). Restoring normal oxygen levels in your blood during sleep is the most critical part of doing that. Keeping those cells healthy (lots of water, lots of vitamin C, lots of oxygen). My stroke risk is high, I take a daily Ecotrin aspirin, so far no strokes or TIA's in over 5 years.

I use cpap to restore oxygen levels, if the treatment your using doesn't do that your wasting your time.

NightHawkeye wrote: Brent, I'd like your take on doing a small trial of CPAP vs APAP. In my field we constantly test things. Some tests are incredibly expensive, but those are almost never done until inexpensive tests have been performed and provided confidence in the expected results.

[remainder snipped]

The portion of your proposed study dealing with APAP vs. CPAP efficacy and compliance has been done and published a couple of times. I don't have my notebook with me but the conclusions are that the APAP will very slightly undertreat the OSD but not enough to matter. At least one study found a little better compliance and the other found the same compliance between the two modes of treatment. IIRC, the patient satisfaction was higher with APAP.

Of course that was just a straight-up comparison of the types of machines. Both involved the usual-care followup by a sleep doc. I'm not aware of anyone doing a trial where you expect the patient to come up with their own settings. The problem with that would be that people willing and able to do that on their own are quite different from people who require followup by a physician and equipment techs. So if you found a difference in the outcomes there's no way to know if it's the treatment making the difference if it's all due to different outcomes for those types of people. We'd say that the randomization to treatment condition was subject to a self-selection bias and that patient characteristics were confounded with condition when you try to interpret the results.

Nonetheless, you could certainly do a study like that. It would be super expensive but even a simple study like that totes up a surprisingly large cost when you actually do it to any decent level of rigor. Not millions but certainly hundreds of thousands of dollars to do it with a hundred or so subjects.