When I recently wrote about the new HBOT -for-autism study (Rossignol et al. 2009) 1, I took issue with unlikely claimed treatment pressures for at least one of the study locations. While a potential methodological weakness, this is probably a fairly small problem in light of potential issues with blinding and interpretation of the results as quantitatively and objectively meaningful with respect to autism. But let’s set those potential issues aside for a moment.
Let’s assume that treatment with slightly enriched air (24% vs. 21% oxygen) in an inflatable hyperbaric chamber pressurized to 4 PSI2,3 above ambient atmospheric pressure, could confer some sort of benefit to an autistic child.
I’m not suggesting assumption that it does confer benefit. I’m asking readers to set aside any knowledge of hemoglobin’s role in oxygen transport, as well as any knowledge of real hyperbaric oxygen therapy (breathing 100% oxygen at greater than 1 ATA ) 4, and evaluate a simpler proposition. Accept the proposal that some sort of benefit is scientifically possible, but then ask yourself a fairly simple question:
Compared to 24% O2 at 4PSI above ambient atmospheric pressure in an inflatable hyperbaric chamber, equivalent oxygen delivery can be achieved with simple oxygen therapy (an oxygen mask) at a fraction of the cost 5 – why is a study of the hyperbaric version of this increased oxygen important?
One possibility: studying what’s already for sale
While some might call it being on the “cutting edge”, others may consider it putting the cart before the horse. No matter how you see it, it’s no secret that some Defeat Autism Now practitioners were already selling this type of hyperbaric oxygen therapy well before this study came out. It should be noted that this study’s authors did disclose this conflict of interest with respect to derivation of revenue in their clinical practices from HBOT.
DAR, LWR, SS, CS, AU, JN, EMM, and EAM treat individuals with hyperbaric treatment in their clinical practices and derive revenue from hyperbaric treatment.
Lisa Jo Rudy over at autism.about.com 6 had additional comments about the subject:
Dr. Rossignol is “the” proponent of HBOT, and has been speaking at conferences all over the world in support of the treatment. Clearly, he has a personal and professional stake in seeing that the outcomes of a research study are positive.
The present study was funded by the International Hyperbarics Association, a trade group of private hyperbaric therapy centers. Clearly, they have a similar stake in seeing positive outcomes.
While there may certainly be an aspect of genuine scientific interest in understanding if this type of hyperbaric oxygen therapy is beneficial for autistic kids, I think there may also be a certain degree of assumption that it is. After all, why would a practioner already be selling something if they didn’t “believe” it worked? Given the stated conflicts of interest, it doesn’t seem implausible that the authors might have an interest in seeing a long-term revenue stream that could come from additional, and deeper pockets than those of parents willing to “believe” and pay – despite the lack of really convincing scientific evidence at this point.
Consider the following portions of an interview with Dr. Dan Rossignol 7:
We chose 1.3 ATA because a lot of children with autism are currently receiving this dose and we are hoping to prove that it works.
“Hoping to prove that it works.”
Dr. Rossignol’s point does not seem unclear. HBOT is popular, and he is, in his own words, “hoping to prove that it works”. This is a valid reason, I suppose, if he is also open to the possibility that it may not, or that it may be a completely moot point if something on the order of one tenth of the cost can do the same thing. Following Dr. Rossignol’s communication about the hope to “prove that it works”, the interviewer asks:
How is the insurance situation coming along?
Insurance situation? Coming along? Was this situation already a well-known “work in progress” back in 2006 (e.g. had it been decided by some, prior to the science, that “mild” HBOT for autism does work, and that insurance reimbursement is really the goal now? Let’s see if we can get Dr. Rossignol’s take on this.
Well, obviously, HBOT is not approved for autism, but we hope to get there. Interestingly, if you take the ABC scale and look at the lethargy subset score, we saw a 49% improvement in symptoms at 1.5 ATA with a p-value of 0.008. If you look at the New England Journal of Medicine study on risperidone from 2002, there was a 56.9% improvement on the ABC irritability subscale with a p-value < 0.001. So the results we had on these 6 children with 1.5 ATA approached the percentage improvement seen with a drug approved for the use in autism. We just need to be able to reproduce these type of findings in a placebo study.
I don’t necessarily see a geniune scientific perspective here, but that could just be me. I get more of a vibe (at least from this interview), that the interest may lie more in “finishing” the studies and showing “that hyperbaric therapy works”, rather that actually finding out, with really good quality scientific methodology, whether or not it really does work. I’ll acknowledge that I could be wrong about this. Do you think readers will have noticed that the study result mentioned for comparison, was from 1.5 ATA, and probably totally irrelevant to the 1.3 (or less) studies?
Is it just me, or would it seem naive to wish that a few studies like the recent one, are really going to catalyze insurance reimbursement in the long run? I get the impression that many parents may believe this. Insurance companies work to achieve cost efficiencies. One of the ways they do this is by reimbursing at higher rates for equivalent things at lower costs – hospital stays in contracted facilities, generic drugs as compared to name-brand versions, etc. Why on earth would an insurance company reimburse for a 4-5% increase in blood oxygen content for a couple of hours at a time, in an inflatable hyperbaric chamber (at a few thousand dollars a month), when the identical oxygen increase could be delivered with a simple oxygen mask (for under $200 a month)?
You don’t have to take my word for this comparison of oxygen delivery, you can take Dr. Rossignol’s acknowledgement in that same interview:
Some people have criticized using mild hyperbarics at 1.3 ATA because they state that when compared to this pressure, you can get just as high an oxygen concentration in the blood with oxygen by face mask without a chamber. And this may be true in some cases.
In fact, it’s true in most (if not all) cases. The physics of partial pressures does not discriminate. But there may be more to the story.
Squeeze in some hope
After acknowledging the reality of the partial pressure comparison problem, Dr. Rossignol continues:
However, we must remember we are dealing with 2 separate components with HBOT — the oxygen and the pressure. So it appears that many of the effects of HBOT are from the increased oxygen, but we cannot dismiss the pressure effect. I think we need more studies on this as well.
So “many of the effects” are from the oxygen increase, but we can’t dismiss the pressure effect? What pressure effect? Is there a demonstrated significant clinical effect for autism from a very slight, and very temporary, increase in atmospheric pressure alone?
Although I suppose it is possible, a clinically significant effect for autism at such low pressures doesn’t seem likely at all. If it turns out that I am incorrect, this may be good news for some of the parents of autistic children in several U.S. cities: Albuquerque, NM (5312’ AMSL ), Aurora, CO (5471’ AMSL ), Colorado Springs, CO (6035’-7200’ AMSL ), Denver, CO (5280’ AMSL ), Reno, NV (4505’ AMSL ), and Salt Lake City, UT (4226’ AMSL ), to name a few. Something as simple as a move to a closer to sea-level city might provide increases in atmospheric pressure not a lot unlike those provided by the inflatable hyperbaric chambers. If there were some beneficial effect of slight additional atmospheric pressure for autism, certainly there would have been some observations (anecdotal or media reports) over the years, of families with autistic children who moved from states like Colorado to lower elevation states like California – and noticed. Who knows? Perhaps this is something to yet be uncovered.
So, aside from the fact that an identical oxygen increase can be achieved with simple O2 therapy without a hyperbaric chamber at all (and at a fraction of the cost). And, aside from the point that the minute pressure increase (while certainly possible in a strict scientific sense) isn’t known to be a likely candidate to significantly clinically impact autism, is there anything else about this newest HBOT -for-autism study that may merit some critical thought? Maybe, but it’s really just a side-note (perhaps interesting to some, but not terribly relevant to the science itself).
Who farted in the HBOT chamber? (Shh!...Don’t say it’s expensive)
The original manuscript 8 for this study contained what I thought was an appropriately realistic comment from the authors in the conclusion. This comment has value in terms of practical knowledge that readers who are not familiar with hyperbaric oxygen therapy would probably find useful. What follows is the first-draft conclusion of this study with that comment emphasized.
Hyperbaric treatment is a relatively time-intensive treatment and can be costly. However, given the positive findings of this study, and the shortage of proven treatments for individuals with autism, parents who pursue hyperbaric treatment as a treatment for their child with autism can be assured that it is a safe treatment modality at the pressure used in this study (1.3 atm), and that it may improve certain autistic behaviors. Further studies are needed by other investigators to confirm these findings; we are aware of several other planned or ongoing studies of hyperbaric treatment in children with autism.
Again, Lisa Jo Rudy over at autism.about.com notes:
No insurance company will cover the very high cost of HBOT for autism, as it is considered an experimental and unproven therapy.
But the above conclusion is not the conclusion that appeared in the peer-reviewed, edited version. Here it is:
Given the positive findings of this study, and the shortage of proven treatments for individuals with autism, parents who pursue hyperbaric treatment for their child with autism can be assured that it is a safe treatment modality at the pressure used in this study (1.3 atm), and that it may improve certain autistic behaviors. Further studies are needed by other investigators to confirm these findings; we are aware of several other planned or ongoing studies of hyperbaric treatment in children with autism.
Why would the authors remove that valuable bit of practical knowledge about time requirements and high cost? Apparently due to a comment from referee #3 for this paper.
Opening the conclusion with negative comments demeans the study? Such comments don’t really touch the content of the study itself, and what the now absent comment did do, was provide some practical perspective – quite likely, very accurate practical perspective. Why would it be suggested by referee #3 that the practical comments demean the study? Perhaps it was meant that the comments demean the use of mild hyperbaric oxygen therapy as an autism treatment (therefore actually demeaning a desired interpretation of this study)? That would seem a real possible concern, since the justification offered, has absolutely nothing to do with the study itself, and doesn’t amount to much more than logical fallacy and simple assertion.
“Many other inventions used for ASD children are equally time consuming…”
This is about as basic an example of the “two wrongs make a right” fallacy as can be presented. Two wrongs don’t make right. Just because other interventions are also time consuming, does not mean a researcher is unjustified, or shouldn’t add the point about practicality that HBOT is relatively time consuming. Further, if the authors are aware of such a potential practical issue, it could be argued that ethics would dictate that it is mentioned. Other treatments presenting similar impracticalities do not automatically relieve any potential ethical responsibility in this regard.
“...hyperbaric treatment need not be expensive.”
Compared to what? Hyperbarics in a gold-plated hyperbaric chamber? If there is no significant effect for autism from the brief, and small increase in added pressure in one of these inflatables, the increased oxygen delivered by providing 24% O2 at 4 PSI above ambient atmospheric pressure, is easily matched (or exceded) with simple O2 therapy. In short, this type of hyperbaric treatment would be the hard way, and the expensive way to achieve the results.
Referee #3 also added the following comment:
The reviewer has a preference for the word treatment rather than ‘therapy’. In view of the proven changes that relate to increased inpsired fractions of oxygen it is suggested that treatment would be preferable.
The “T” in the acronym “HBOT” does, in fact, represent the word “therapy” in medical usage. I happen to think the terms “treatment” and “therapy” are fairly interchangeable in the context of drug delivery, but I do wonder if there is any significance to such a preference. Is this a semantics issue that has the potential to impact perceptions of those who make decisions about insurance coverage for autism? But I digress. So what’s up with these comments from referee #3, comments with a little fallacious reasoning, that express possible concern about the perception of a high price tag for mild hyperbaric oxygen therapy, and a commment that communicates a preference for the word “treatment” over “therapy”?
I honestly don’t know. What I can tell you is that referee #3 was Philip James, MD. Dr. James is a professor in the field of hyperbaric medicine and hails from the U.K. He appears to have published quite a bit in the field of hyperbaric medicine as well.
According to the International Hyperbarics Association website:
Dr. James is responsible for founding the Hyperbaric Trust in the United Kingdom which promotes the treatment of cerebral palsy and the brain injured child and was responsible for having the National Health Service pay for this therapy.
Dr. James (Referee #3) appears to have been categorized (with a doctor profile) as a medical advisor to International Hyperbarics Association back in February of 2006 (shortly before this study 9 began). Hey wait a minute, there’s that name again – International Hyperbarics Association. Where have I seen that before? Oh yeah, in the study itself:
We are grateful for the work of Shannon Kenitz of the International Hyperbarics Association (IHA) for an unrestricted grant which funded this study, which included use of hyperbaric chambers and funding for all hyperbaric technician salaries during the study. The IHA had no involvement in the study design, collection, analysis, interpretation of data, writing of the manuscript, or in the decision to submit the manuscript for publication.
I’m not sure how the International Hyperbarics Association defines itself exactly – are its listed medical advisors excluded from that definition? That would seem likely.
As of this writing, Dr. Rossignol is listed as a medical advisor at the IHA website. 10
Side notes aside, where to, from here
So all in all, it seems that “mild” HBOT -for-autism researchers may have their work cut out for them. Although probably not very likely, it is possible that a small temporary change in atmospheric pressure could do something for autism, and that should be studied next, then, better replications should follow.
In the long run, it will be difficult to ignore the scientific fact that simple oxygen therapy alone can easily provide identical increases in blood oxygen content, at a fraction of the cost of mild hyperbaric oxygen therapy (as it currently being studied for autism). If HBOT -for-autism proponents think insurance companies should step up to pay for an expensive treatment that provides a 4-5% increase in blood oxygen (without scientifically establishing benefit of the small and temporary pressure increases), they might do well to consider these famous words (most recently from Barack Obama ) – “You can put lipstick on a pig. It’s still a pig.”
1 Hyperbaric treatment for children with autism: a multicenter, randomized, double-blind, controlled trial
2 Medical device pre-market notification (FDA-cleared)
3 Manufacturer product sheet
4 Definition of Hyperbaric Oxygen Therapy
5 Hyperbarics and Hypotheses
6 Hyperbaric Oxygen as a Treatment for Autism: Let the Buyer Beware
7 Interview with Dr. Dan A. Rossignol: Hyperbaric Oxygen Therapy Improves Symptoms in Autistic Children
8 Pre-publication history
9 ClinicalTrials.gov Identifier: NCT00335790
10 Medical Advisors
11 Index of /docs
12 International Hyperbarics Association Medical Advisor – Professor Philip B. James, M.D.