Tuesday, February 27, 2007

Quote Mining and Misrepresentation: Poor Ways to Claim Clinical Validation or Sound Science

Cat with rifle poised at a window. The caption reads When all else fails, vote from the rooftopsThis year I have read a number of poor papers and a remarkable number of assertions that rely upon quote mining or misrepresentation to conjure up scientific respectability for some very dubious claims. A lot of this experience and disillusionment is related to the literature and claims around IgG testing for food intolerance despite the published position of relevant professional associations that find no support for the clinical use of IgG testing for food intolerance.

I've addressed the matter of Patrick Holford's endorsement of IgG food intolerance tests in a previous post. Holford is a nutritionist for whom recommending these tests is an expansion of his own commercial offerings so his endorsement in understandable although his claims of "sound science" behind IgG testing are not. I'm rather more troubled by Allergy UK's endorsement of IgG testing; particularly because they presented evidence to a Select Committee on Health that they deal with 60,000 requests for assistance in a year, and say that "the number of people seeking advice had grown on average by 21% in each of the last three years". It is obvious that people turn to them in expectation of authoritative information. Allergy UK is a medical charity; people who request assistance might expect their endorsements to be thoroughly researched and a reflection of current bio-medical research and opinion.

Muriel Simmons of Allergy UK is liberally quoted by a commercial laboratory that offers direct-to-consumer testing (YorkTest): she is quoted as endorsing a number of their allergy (e.g., the multi-allergy screening test) and intolerance tests. Surprisingly, the Allergy UK website does not provide a summary of the research to support this position on their website. There is a buried reference to Whorwell's paper that investigated IgG testing and an elimination diet in the treatment of irritable bowel syndrome (IBS). Although others may have quote-mined or misrepresented the extent to which their work can be generalised, Whorwell and his co-authors responded to comments about their reported findings and were punctilious in defining the limits of a reasonable interpetation of their results:
it is entirely possible that IgG antibodies may be important in IBS, where we now know that there is an inflammatory component in some cases, whereas they may not be relevant in food intolerance in general. Furthermore, it is likely that only a subset of patients are likely to have an immuno-inflammatory basis to their condition and these might be the very individuals who respond to dietary exlusion based on IgG antibodies. This would fit with our results where only a proportion of patients responded despite all having antibodies. This, of course, limits the specificity and usefulness of the test unless such subgroups can be indentified beforehand. [Emphases added.]
For several years, Allergy UK and YorkTest have made references to research that is in progress. Some of this research was published recently and addresses Dietary advice based on food-specific IgG results.

The PR release for the Allergy UK-sponsored study claims the following:
The new study...is the largest ever food intolerance study undertaken in the UK and reveals for the first time that over 60% of patients involved in the study had to endure over 3 years of NHS appointments, suffering and misdiagnosis before obtaining improvement through the food intolerance testing.

5200 people took part in the study and were treated for a wide range of mild and chronic illnesses. In addition, nearly a third of all patients received NHS treatment for over a decade without success. 32.4% of the sample showed they had suffered with their condition for over ten years before taking up a food intolerance health solution.

At the other end of the scale just 5% of patients had illnesses lasting from 1-6 months before using food intolerance and 22% were upto 35 months before seeking a non-NHS resolve via food intolerance testing.
Other PR-reported findings in the study reveal:
  • Over 3 out of 4 patients get better from their original symptoms.
  • 68.2% of patients benefited within the first three weeks.
  • 9 out 10 patients had a return of symptoms when introducing offending foods back into their diet.
  • Many patients would rather have a dietary solution than taking medication.
  • Patients who reported more than one condition were most likely to report improvement.
  • On average, patients had symptoms for at least 10 years before taking up a food intolerance option.
[Edited 1 March.YorkTest has made some remarkable claims about this study: 10 years of NHS treatment and we're still ill*.] I find these claims to be a little extravagant when there that is no attempt to obtain objective measurements, nor attempts to correlate with medical records and the study covers a 3 month period but I was optimistic that access to the full paper would resolve my misgivings.

I located a copy on Gillian McKeith's site (it is possibly a pre-publication copy). I was hopeful that the paper would answer some of my questions, particularly as it has been bruited about as having significant findings about IgG food intolerance testing, dietary modification and chronic illness.

I have been disappointed on a number of fronts. Other issues aside, it is bewildering that Hardman and Hart refer to the survey participants as patients: neither of the authors is medically qualified and there is no indication within the paper that those who responded to the survey are under medical care for their self-reported symptoms or illnesses. By referring to patients the authors imply that all of the participants are patients and that there may be some form of validation for their symptoms and illnesses. It is understandable that the PR release lards its text with references to the NHS, treatment, and patients but it is potentially misleading if it leads people to believe that this work is NHS endorsed or was being offered as a treatment programme.

There is no explanation as to why there are two questionnaires, nor do the authors provide a clear list of the differences between them. Participants received one survey, 3 months post-test: there was no recorded baseline of symptoms and diet. Any claims about either symptoms or diet must be retrospective. Further, we don't see the questions so it is difficult to evaluate some of the claims and findings and how the response may have been manipulated by the form of the question.

The postal survey does not tell us what the respondents were eating before their intolerance testing. If people have been speculating about food problems in relation to their illness for some time, it is possible that they may have experimented with an elimination diet that may have skewed the results of their IgG testing. E.g., if somebody had been avoiding soya for some time they would probably have a negative IgG test at that time whereas they might have a positive result with recent exposure.

Likewise, it would not be too difficult to imagine that people who are chronically tired or experiencing 'brain fog' might not prepare food from scratch on a regular basis. It is possible that the striking improvements in well-being might occur in anyone who shifts from a diet of processed food to home-prepared 'healthy' meals. The best way to test this would be to find a group of people who are chronically tired etc. but switch them to a more wholefood way of eating without any food intolerance tests. Actually, that sounds like a number of diet makeover T.V. programmes which show startling results when people change their way of eating (although, to be fair, they usually start exercising as well).

The participants in this survey had previously purchased a direct-to-consumer 113 foodSCAN test from YorkTest. They sent a small blood sample to the laboratories for testing. The testing evaluates the level of IgG in response to the panel of foodstuffs. The consumers receive a report in their levels of food-specific IgG are listed, and they are advised to avoid those foods with increased antibody levels (the red, yello and green system). The lab results are accompanied by helpful food lists and food rotation instructions. As part of the service package, the consumers have limited phone time with a nutritional adviser.

Hardman and Hart do not discuss the IgG results: it would have been interesting to know if the positive IgG results clustered around the usual suspects of wheat, milk, shellfish, citrus fruits etc. or if they were evenly spread throughout the 113 test foods. An analysis like this would be valuable in designing a placebo diet for use in any future research involving IgG-guided elimination diets.

A high number of survey participants claimed to have "rigorously followed their elimination diet" however, this depends on their subjective assessment and recollection. There is no reference to any request that participants should keep food diaries so these recollections may be unreliable. Even those participants who made a "reasonable attempt at the diet" (N.B., there is no explanation of what this means) reported "noticeable improvement". So, these findings may suggest that making a few changes, which may not necessarily reflect the IgG testing results, is effective enough to question whether it is worth the added inconvenience of implementing a rigorous elimination diet.

There is remarkably little discussion of the finding about the relationship of response to the food elimination diet and symptoms:
The information obtained from asking which was the primary condition that concerned patients was grouped into diagnostic categories. As previously mentioned this question was not asked of all patients as it was only part of the first questionnaire. Of the 2221 replies 38.0% were gastro-intestinal, 13.7% were dermatological, 10.7% were neurological, 10.1% were respiratory, 9.4% were psychological, and 6.2% were musculo-skeletal. 11.9% were categorised as ‘other’.

The distribution of benefit reported varied according to the medical condition of most concern...For example, 40.6% of patients reporting psychological problems as their main concern report high benefit from dieting rigorously, whereas only 21.0% of those reporting respiratory or musculo-skeletal problems as the main concern reported high benefit. [Emphasis added.]
It does have to be said that some of these results would be comparable to a placebo condition: in an IBS study, the researchers "estimated that approximately 40% of the placebo arm would report a significant improvement in symptoms". Hardman and Hart summarise their audit of the survey:
All the measures considered were categorical and based on self reported perceptions so quantification of comparisons was not possible. However, there was consistent evidence that noticeable benefit was gained from removing offending foods from the diet. 75.8% of those that rigorously followed the recommended diet had a noticeable improvement in their condition. 68.2% of those that benefited from following the recommendations felt benefit within 3 weeks of following the diet. The survey covered subjects with a wide range of medical conditions, and it was clear that those who reported more than one condition were more likely to report noticeable improvement. 81.5% of those that dieted rigorously and reported three or more co-morbidities showed noticeable improvement in their overall condition.
The authors reported some widely different findings about challenges with the 'offending' foodstuffs.
Subjects were asked specifically to say whether the result of reintroducing foods was a strong return of symptoms, a slight return of symptoms, or no change. Of the 3026 subjects that responded to the second questionnaire, 2275 (75.2%) said they had reintroduced offending foods either on purpose or by accident. 2219 of these patients also answered the question regarding the return of symptoms. 824 (37.1%) reported a strong return of symptoms, 902 (40.6%) reported a slight return of symptoms, and 493 (22.2%) reported no change. That is 77.7% reported the return of symptoms after the reintroduction of offending foods...

Those reporting more benefit were more likely to feel a return of symptoms after reintroducing offending foods. For those who dieted rigorously and reported high benefit, 92.3% felt a return of symptoms after reintroducing offending foods.
Obviously, the participants were typically aware that they had eaten "offending foods" and it is probable that this is reflected in the results. It would have been interesting to have had a breakdown of the symptoms or conditions that were most likely to recur upon re-introduction of "offending foods" and what these foods were.

When people follow elimination diets, it is not unusual for them to adopt a de facto low carbohydrate way of eating. This may be particularly true when consumers are guided by the results of a food intolerance test because if they are advised to eliminate foods such as wheat, they may find it difficult to replace this with another (safe) carbohydrate source. They may be unwilling to replace (say) wheat with quinoa if they were not tested for quinoa. So, it is possible that a number of people in this survey who showed the strongest reaction to the reintroduction of foodstuffs might have been exhibiting a reaction that reflects a disturbed glucose metabolism that is related to carbohydrate restriction. Bethune and colleagues have previously reported that this phenomenon can be interpreted as food allergy.
All three of the patients described developed symptoms several hours after meals and attributed these to food allergy. Further restriction of carbohydrate intake exacerbated their problem. Symptoms continued to occur after meals and were erroneously interpreted as further evidence of their carbohydrate allergy.
The researchers discuss 3 case studies and report that
[o]nce patients have a fixed belief about a cause for their symptoms, it may be difficult to persuade them to entertain an alternative diagnosis. In case 1, negative results of blinded food challenges did not dissuade the patient from her belief that food allergy was the cause of her symptoms.
Because Hardman and Hart report on their audit of the YorkTest 113 foodSCAN but do not provide sufficient detail in the paper, the reader is reduced to speculating about plausible mechanisms for the results. There is no reminder that these results only cover a 3 month period, we do not know if the reported improvements persisted. The authors conclude:
The observation of a clear relationship between adherence to the diet and outcome is critical in showing that the diet is an ‘active treatment’. Similarly the fact that over three-quarters of subjects who reintroduced offending foods back into their diet, whether on purpose or by accident, showed reoccurrence of their symptoms. These two criteria are the basis for the diagnosis of ‘food intolerance’ by the laborious elimination diet process which, it appears, can be largely ‘bypassed’ by following a diet based on the results of food-specific IgG testing. The percentage of patients reporting noticeable improvement suggests that such specified elimination diets are a valid intervention in the relief of certain symptoms. The degree of success varies with the type of problem being experienced.
I can not agree that these survey results support these conclusions. Without examining well-maintained food diaries, it is impossible to quantify the number of people who did alter their diet rigorously: the results indicate that even those who followed an elimination diet of some sort (that does not necessarily adhere to the IgG results) will produce results and therefore qualify as an "active treatment".

Similarly, Hardman and Hart are not entitled to claim support the diagnosis of food intolerance based on the reaction to the reintroduction of "offending foods" because the participants did not attempt a blinded food challenge. Young and colleagues published a classic population study of food intolerance where there was a perceived prevalence of food intolerance of almost 20%, but the clinically definitive double blind placebo food challenge test indicated a rate of less than 2%.

Hardman and Hart acknowledge the equivocal status of IgG as a marker for food intolerance in the introduction:
the exact role of IgG antibodies as markers of food intolerance in general is not clear. IgG antibodies to food antigens are often present in healthy individuals and are generally considered to be part of the normal immune response to food allergens [refs].
However, they do not comment any further on this in their discussion of the findings of this audit. I hope that this reticence is continued by others and that there is no attempt to misrepresent this audit as supportive of the "sound science" of the IgG diagnosis of food intolerance or the "clinically validated" virtues of an IgG-guided elimination for the treatment of a variety of symptoms and chronic medical conditions.

In the UK we have very poor provision of allergy diagnosis and management. People report that GPs are wary of the validity of allergy and intolerance and that it is very difficult to obtain a referral to the limited NHS services that do exist. The cause of appropriate allergy provision may be damaged by its association with the dubious science of food intolerance testing.

A diagnosis of food allergy should be confirmed by a clinician with an understanding of the multisystem, polysymptomatic patterns of illness involved. A careful history will usually reveal these patterns and suggest a diagnosis that can be made on clinical grounds. Clinical allergists rely upon an interpretation of the history and the tests; however, there is no wholly definitive laboratory test because an interpretation of the results relies upon the clinician's understanding of somebody's complex allergic responses. E.g., a clinician may need to interpret the individual and relative levels of several antibody series, such as IgE, IgG, IgA and IgM. There may be complex shifts in the distribution of IgE, IgG, IgA and IgM that indicates immune activity in response to antigen loading. Patients who have severe or prolonged food allergy may have depressed levels of IgM and IgG; they may also have lower white cell counts. If IgE levels are low, this may compromise the clinical value of both skin testing and IgE RAST. Overall, a high IgG might be associated with an immune-mediated diseases, and reflect increased antibody production, possibly against unknown antigens.

The status of IgG testing in diagnosing food intolerance is controversial. It is premature at best and boarding on deceptive to claim that IgG testing for food intolerance is "clinically validated" or has "sound science" behind it. There is so much mis-information on the internet that it would be helpful if the British Society for Allergy and Clinical Immunology (BSACI) would issue a position statement on the matter (however, Prof. Kay, a former president of BSACI has made some lack of scientific support for this use of IgG testing). Both BSACI and Allergy UK are core members of the National Allergy Strategy Group. Membership of such bodies adds to the status and authority of Allergy UK and their endorsements. It is unfortunate that Allergy UK gives the imprimatur of respectability to IgG testing in the diagnosis of food intolerance.

*Allergy UK and YorkTest have been flagging up this audit for some time. I've seen references to more than 7000 participants, 5000 participants, and for the relevant claim about unsuccessful treatment by the NHS, this is now modified further:
The findings, conducted by York University, suggest a growing dissatisfaction among patients who wasted time and money on treatment on the NHS. The study using 3219 patients and published in the February issue of Nutrition and Food Science looked at a range of mild and chronic illnesses including migraine / headache, skin symptoms, IBS, and digestive problems.
Why have neither Allergy UK nor YorkTest made the full detail of this study available. According to the published paper, this was a questionnaire with scaled category responses. However, from the current claims, it now seems as if the participants were invited to complain, or spontaneously complained about their NHS treatment. This study is very poor; the claims being made for it are over-blown and disproportionate. Readers can not possibly assess these claims of NHS mis-treatment or mis-guided treatment if we have no way of discovering which treatment modalities were attempted.

YorkTest also has the chutzpah to promote an obscure petition to provide free food intolerance tests on the NHS. Their pious hope is that the petition:
re-enforces the view that the NHS should put peoples health at the forefront of its health service strategy. If the petition takes off, then it could make the health minister sit up and take action in saving the health service thousands of pounds whilst freeing up doctors valuable time.

At best this petition might make the stakeholders of the health service to look at what is best for the people it aims to help and accept it as a credible and fast alternative to dishing out a diet of pills and potions. [I have not sic'd the errors.]
There is no decent science behind IgG food intolerance testing. Leaving that issue aside, YorkTest is now claiming that an IgG-guided elimination diet is a "credible and fast alternative"? Unusually enough, words fail me. [Edited: It is possible that somebody associated with YorkTest instigated this e-petition.]

It is time to publish the questionnaires and the full data from this audit. Without the full information it is impossible to evaluate the claims that are being made and that is an unsatisfactory situation that may well lead to many mis-understandings.

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Sunday, February 25, 2007

Vaccination v. Faith in Vitamins: Touching, But Insufficient Evidence

Images of children's vitamin preparationsIt's been a very odd week. The sort of week that makes me wonder whether all the media coverage of health matters has about as much relevance to the nation's health as the cookery programmes, columns and features have to the nation's cooking skills. I think that vaccination is a medical and social marvel and I state my arguments in favour of it whenever people tell me that vaccination is ineffective, irrelevant, dangerous etc.

This week, I was told that my stance on vaccinations is proof that I am a fool and a pharma shill which is par for the course. I was informed that it has been proved both that healthy children don't get childhood illnesses and that if they do, those illnesses strengthen their immune systems. It is hard to pin down the origin of these assertions (although I have located one egregious documentary in which these claims are included (I will discuss this at another time); in the interim, Skeptics has put up a fine examination of Dr. Scheibner's 'science').

The example that was quoted to me was measles. Apparently, it is only those children who are deficient in vitamin A who develop measles; just to cover all of the bases, the categorisation of 'deficient' applies both to those with clinical and sub-clinical deficiences (of course). I was told that WHO had used vitamin A with remarkable success in developing countries.

I attempted to distinguish between vitamin A being used to prevent measles infection or to reduce the morbidities of children who had already contracted measles. I pointed to the remarkable reduction in measles' deaths thanks to an aggressive vaccination programme. The success of the Measles Initiative reflects the increased uptake in measles vaccination; the countries involved have not suddenly had a influx of quickly-built civil engineering projects that have provided clean water and better sanitation. Nor, sadly, has there been a remarkable upswing in the nutrition of the children. There is no evidence of a co-simultaneous vitamin A supplementation programme in the same countries that were covered by the Measles Initiative. Vaccination is responsible for the different outcomes for these children. I argued that prevention (vaccination) was much better than treatment and less devastating for the child.

I was then informed that having childhood illnesses like measles protects you from developing cancer and a range of auto-immune diseases. In the following quotation, I'm unclear as to whether it is the vaccines that stand accused of causing these dread diseases or the lack of immunity conferred by failing to contract preventable childhood illnesses.
There is growing suspicion that immunization against relatively harm-less childhood diseases may be responsible for the dramatic increase in auto-immune diseases since mass inoculations were introduced. These are fearful diseases such as cancer, leukemia. rheumatoid arthritis, multiple sclerosis, Lou Gehrig's disease, lupus erythematosus, and the Guillain-Barre syndrome. An autoimmune disease can be explained simply as one in which the body's defense mechanisms cannot distinguish between foreign invaders and ordinary body tissues, with the consequence that the body begins to destroy itself. Have we traded mumps and measles for cancer and leukemia? [I'm not going to sic out all the errors in this piece. N.B., I'm horrified at what this link will do to this blog if it is submitted to the Black Duck's quackometer but these things have to be discussed.]
Nonetheless, it wasn't difficult to find epidemiological studies to rebut these claims: e.g., a study that reported no possible causation between MMR vaccines and Guillain-Barre Syndrome.

Dr. Flea has compiled More notes from the lunatic fringe and reports sightings of claims that Shaken Baby Syndrome (SBS) is a mis-diagnosis of vaccine injury. The vaccine injuries in question include scurvy which is said to be responsible for the pattern of bony injuries seen in SBS. Dr. Scheibner claims that her services are in demand as an expert witness in SBS legal cases and as an expert addressing governmental committees. Dr. Kalokerinos is the source of many of the claims about scurvy as a vaccine injury (you can read more about him, courtesy of Rat Bags discussion of a meeting that Kalokerinos addressed) during which he claimed that:
massive doses of vitamin C would cure just about every ailment, and that vaccination was a deliberate process of genocide carried out under the auspices of the World Health Organization and the Save the Children Fund. He went on to say that these two groups "put Hitler and Stalin in the shade" when it came to deliberate and intentional mass killings. [Emphasis added.]
I did try to consult Kalokerinos' papers on Entrez PubMed but because most of them had been published in the Australasian Nursing Journal, none of the abstracts were available and I haven't been able to find them in the British Library. I've had to fall back on an extract from one of Kalokerinos' books to learn more about his claims for the value of vitamin C:
The matron was convinced that the diagnosis was meningitis so she prepared a lumbar puncture. I had however, seen this problem before. Lumbar punctures performed by me had been negative and the infants died....the trauma of inserting a needle..might result in a haemorrage that might cause spinal cord paralysis. So I decided to give an injection of vitamin C..I probably gave as many as 6 injections, each 100mg. After half an hour Mary was normal. It was hard to believe, but I had performed a miracle!...I found that any viral infection, including measles and hepatitis, could be dramatically 'cured' by administering Vitamin C intravenously in big doses--provided that treatment was commenced early. Dr. Kalokerinos MD (Medical Pioneer of the 20th century pg. 175.) [Emphasis added.]
Kalokerinos claims that without his vitamin C intervention, 1 in 2 aborigine children were dying after vaccination. Unfortunately, without being able to consult any of his papers on the matter (and I have reason to believe that none of these is a substantial or refereed paper), these claims are only available in his books, e.g., Every Second Child.

Reading about these self-styled voices in the wilderness and truth-tellers encouraged me to adapt a piece that was recently written about autism 'experts'. The similarities are striking.
So these mavericks continue to circulate, paddling in the same scientific shallows, attending the same conferences and boasting connections with the same research institutes. They travel the world quoting each other in circular support, reinforcing a fringe belief in unproven interventions for [vaccine injuries] and propagating the mistaken view that ordinary doctors are cowed by mysterious vested interests (pharmaceutical companies?) into not doing their best for children...

Their [anti-vax] agenda is, regrettably, assisted by newspapers with acres of space to fill, who delight in feeding the middle-class paranoia over perfect parenting...

There is nothing wrong with a scientist pursuing a hunch, and everything right about parents wanting to do the best for their child. There is nothing even particularly sinister about [anti-vax proponents] gambling [their] reputation on an instinct. But there is something depressing beyond belief about a scientist who refuses to recant in the face of overwhelming opposing evidence.
I am more than a little puzzled that it is acceptable to believe that medicine is involved in a vaccination hoax, conspiracy and deception. I also find it quite touching that some people appear to be so ready to place so much faith in vitamins and vitamin supplements. The latter seem to be necessary because in the West, unlike much of the world, we tend to have sub-clinical rather than verifiable deficiencies. We appear to have been brainwashed into this by the progaganda about the poor nutrition of the average mixed diet. Oddly enough, it is media nutritionists who attempt to convince us of this, and those self-same people tend to have their own brands of vitamins and minerals to remedy those deficiencies.

Now, I think that most parents would readily dismiss most of the stranger anti-vax arguments and refuse to waste precious minutes of their lives even thinking about them. I don't imagine that people who are swayed by these arguments would be at all convinced by discussion about the correct interpretation of medical literature that is cited in support of some anti-vax claims. I also think that it is verging on the impossible to anticipate where the next anti-vax argument will come from (e.g., it's an instrument for genocide; it leads to cancer; it is linked to diabetes; it is linked to a decline in fertility; it's linked to pervasive developmental disorders). You can not successfully counter the bizarre or irrational. Attempting to counter some of the anti-vax stuff that is out there would be a sisyphean task. And yet, I am still horrified at the search results from Google. Irrelevant or worth countering some of the more egregious nonsense?

Edited 28 Feb. I am grateful to a correspondent for sending me a link to The Anti-Immunization Activists: A Pattern of Deception. Dr. Friedlander is board-certified in both anatomic and clinical pathology; he has specifically addressed the misuse of scientific articles by anti-vax activists.

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Paediatric Grand Rounds 1:23 Is Up!

Star - text is Paediatric Grand RoundsPaediatric Grand Rounds 1:23 is up at Allergy and Asthma Source. Dr. de Asis has put together a star-studded spectacular edition of PGR in honour of this edition's proximity to the Oscars. There are many interesting stories with some strong and inspirational dramatic leads being taken in some of them. There are also some recommendations about children's films, a book and a band.

The next edition of PGR will be hosted by Dr. Sam Blackman at Blog MD on March 11. Clark Bartram is looking for more hosts of Paediatric Grand Rounds so please consult the schedule and volunteer your efforts.

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Tuesday, February 20, 2007

Make the Darkness Go Away

A slight flame battles the darkness, it will falter soonMusic can have the tingle factor: the key change in Barber's Adagio for Strings is possibly the best known example. If music affects you, you probably have your own compilations of moving or uplifting music. You probably also have your list of composers who give you backache or a strong urge to leave the room (Stockhausen does both for me). There are various random pieces that can give me the horrors for days if I should hear them; one of these is the Gary Jules' version of Mad World. If I'm out and about and I hear it accidentally, I just want to curl up in the nearest dark corner and draw something over my head, even if it is just newspapers.

The Tears for Fears original of Mad World leaves me unmoved. I don't know why the Jules' cover of Mad World affects me like that but it does. I live with a cloud of misery for a few days that is uncannily like a bout of flu: my family has termed this the Jules Effect and they do their best to make sure that it doesn't happen if they've got anything to do with it. It happened over the weekend. I heard it in a supermarket and couldn't escape unless I was willing to abandon my shopping (I occasionally curse the punctiliously polite upbringing that made this unthinkable). Coming on top of a child that I'd just met, whom I couldn't work with and for whom I couldn't even make any useful recommendations, it just about put the finishing touch to the scorched earth of that weekend.

I still can't write about that child. However, she reminded me of a little boy that I met last year. Obscuring as many details as I can, while conveying some of the essence of his story, this is one of the few times that I've met a child and experienced the Jules Effect. The little boy was two-years old, tow-haired and sturdy. He instantly brought to mind a popular tale about pale cherubs:
Bede's oft-told story about Pope Gregory, who looked on the fair-skinned Angles for sale in a Kent market place and said: "Not Angles but angels."
I'll call him Greg. Despite his sturdy frame, Greg was shockingly pale and he had bags under his eyes. It was tiring to watch Greg's exhaustingly strong startle response to movement and noise. Greg was wretchedly tired and after some initial interest in playing with the other children, he started pulling at his great-grandparents and would only be distracted by a packet of crisps and a carton of juice.

His great-grandparents (on his father's side) had brought him along to a workshop to see if I could work with him. It was initially difficult to obtain a history because the adults veered between anger and distress. Greg had various asthma medications but there was nobody to give them to him. Greg's parents were not anti-pharma but homelife was rather too chaotic for consistent medication to be practical.

Greg's parents had separated some time ago. Greg lived with his mother in a one-bedroomed flat. In the same flat, were two of the mother's sisters and their boyfriends. The sisters were all very young (less than 20 years old) and enjoyed a volatile relationship with each other that sometimes erupted into both verbal and physical fights. The sisters' boyfriends beat them. The adults all go out to clubs and invite people back on a regular basis and generally keep irregular hours. The police are regular visitors. Neighbours have complained. The council has written a warning letter to them threatening to evict them if their behaviour does not change. They've been evicted from a house before and know that the council would have a statutory duty to rehouse Greg and his mother, so they are not interested in changing their ways.

Greg doesn't have a regular bedtime or bedtime routine. He doesn't have a bedroom. He tends to sleep where he drops in the living room. He wakes up several times during the night as people disturb him when they come in and bring visitors back. Regularly, he wheezes during the night but it can be difficult to distinguish between an asthma episode and sensitivity to the tobacco smoke of up to 10 adults in an unventilated room.

Greg's father has had several spells in prison. Although he has been placed in several jobs by various services, he has not remained in any of them. Greg's father is unemployed, effectively homeless and staying with a sequence of friends. He has a new girlfriend who has several children but living together would disrupt her welfare benefits so they don't. Greg's father is determined to keep visiting rights for Greg so he has remained on good terms with his ex-girlfriend and visits Greg most days. If the women fight when he is there, he gets down on the floor with Greg and plays a game with him until it is over.

Greg seems to live on snack food. After his father moved out, there was no one left who prepared meals. Greg's father was also the adult who kept the house clean; in his absence, the flat is now dirty and untidy.

I don't know if you can say that a 2-year old swears, because he doesn't fully understand what he is saying, but Greg can be both aggressive and foul-mouthed. Greg's father knows that the atmosphere of hostility and aggression is harming his son. He has asked both his own parents and great-grandparents whether they would be willing to take in both him and Greg. However, he had a difficult relationship with his mother when he was growing-up and his step-father threw him out of the house when he was 15 and it is only comparatively recently that they have started to meet again. The great-grandparents have so many health problems (several cancers, diabetes, cardiovascular problems, balance issues, short-term memory problems) that it would not be practical for them to take a very young child into their home.

Greg's mother was out on bail while awaiting her trial on the charge of GBH (grievous bodily harm). Greg's father was reduced to hoping that she is imprisoned so that he could apply for custody of Greg and qualify for public housing. He has no expectation that he would ever find a job that he could keep and provide a home for Greg. However, Greg's Social Worker is not optimistic that his father will readily acquire custody; she suspects that the mother may give custody to one of her sisters so that she will qualify for a home and because it would then be easier for her to reclaim custody of Greg.

The great-grandparents were desperate. They blamed themselves and society for several generations of fractured relationships. They wanted to know if "something could be done" for Greg to improve his health and his sleep quality.

I couldn't offer anything. Greg didn't need anything remarkable or innovative just the everyday and straightforward. The work that I do pre-supposes that there are responsible and concerned adults present in the home. Adults who can provide a reasonable homelife, calm an anxious child, clear the nose, dispense medication, provide regular meals and a regular bedtime routine. Greg doesn't have an adult to do this. Adults and a regular homelife are not available on prescription, nor should they be.

There are children who are in even more dire circumstances than Greg's but that was no consolation to me. A lot of people wanted to help Greg, but there was no intervention that would help him. It was like listening to a continuous loop of Jules' Mad World. And now I've met a little girl and the loop has started again.

For more information about the image used in the illustration, click on it or visit the detail on Flickr.

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Monday, February 19, 2007

What is the Significance of IgG Antibodies and Testing?

Sign text reads: Peanuts and peanut dust everywhereI recently highlighted my misgivings about the claims of sound science or clinical validation for IgG testing for food intolerance. Dr. de Asis gives a very helpful and clear overview of food allergy, intolerance and testing. Similarly, Dr. Minocha offers an fine overview of food allergy and tolerance.

I thought that it might be helpful to quote the position of some professional organisations on the topic of IgG significance and testing.

The American Academy of Allergy, Asthma and Immunology commented on the significance of IgG anti-allergen antibodies in September 2006. They observed that a number of commercial labs claim to be able to measure IgG antibodies against common substances: they questioned the clinical significance of the findings. Although this piece probably refers to labs in the US, experts question whether
commercial assays actually measure the IgG antibodies that they report. Also, even if the assays are measuring IgG anti-allergen antibodies, the clinical significance of such antibodies is certainly not clear.
Further comments highlight the controversies surrounding the significance of IgG antibodies. Some researchers argue that the current state of knowledge indicates that IgG antibodies may have a protective role rather than be evidence of harm.
There has been a long-standing debate about the significance of "atypical" (IgG4) anti-allergen antibodies with more observers stressing a possible down-modulating rather than a pathogenic role in allergic disorders. The significance of IgG anti-food antibodies is particularly uncertain since the sera of many children with such antibodies in their serum tolerate the foods in question perfectly well. [Emphasis added.]
The Australasian Society of Clinical Immunology and Allergy (ASCIA) has made a statement on the topic of IgG testing for the diagnosis of food intolerance:
IgG antibodies to food are commonly detectable in healthy adult patients and children, independent of the presence of absence of food-related symptoms. There is no credible evidence that measuring IgG antibodies is useful for diagnosing food allergy or intolerance, nor that IgG antibodies cause symptoms. The exception is that gliadin IgG antibodies are sometimes useful in monitoring adherence to a gluten-free diet patients with histologically confirmed coeliac disease. Otherwise, inappropriate use of food allergy testing (or misinterpretation of results) in patients with inhalant allergy, for example, may lead to inappropriate and unnecessary dietary restrictions, with particular nutritional implications in children. [Emphasis added.]
ASCIA investigate several unorthodox techniques for the diagnosis and treatment of allergy, asthma and immune disorders. They conclude:
Treatment based on inaccurate, false positive or clinically irrelevant results is not only misleading, but can lead to ineffective and at times expensive treatments, and delay more effective therapy. Sometimes harmful therapy may result, such as unnecessary dietary avoidance and risk of malnutrition, particularly in children. For example, Rona and Chinn found that around one half of parents who thought that their child was food allergic or intolerant altered their child's diet, but only one third sought medical advice, and that some children were 4cm shorter than controls. Unnecessary environmental and chemical avoidance, creating a perception of organic illness where none exists, or advising physical interventions when psychosocial factors are the source of symptoms, can impact on employment and social functioning. [Emphasis and link added.]
Although the British Society of Allergy and Clinical Immunology (BSACI) does not have a formal position statement, a former president, Prof. Kay, wrote the following in his written evidence to a parliamentary Select Committee on Health:
good allergy practice is evidence-based and that, as in other branches of medicine, allergy tests and treatment require rigorous scientific validation. At the time it was pointed out that there was a very wide sale and use of highly dubious allergy tests which could lead to wrong diagnosis, inappropriate treatment and the institution of nutritionally inadequate diets which can be harmful, especially to children...

...a number of other unsubstantiated tests which are widely available but have never stood up to any real scientific scrutiny. These include serum IgG antibodies for food allergy ("Yorktest"), iridology, applied kinesiology (muscle testing), cytotoxic food testing—ALCAT, electrodermal skin tests—VEGA testing, ELISA/ACT and hair analysis.

Thus I fully support the Evidence to Select Committee on Allergy Services offered by the British Society of Allergy and Clinical Immunology (BSACI) and draw your attention in particular to their concerns regarding the uncontrolled proliferation of unconventional allergy services. In my opinion these flourish because, at present, the NHS is seriously lacking in main stream, evidence-based allergy specialists and attendant facilities.
It would be unfortunate if the frequent conflation of allergy and intolerance, and the questionable science behind the commercially available tests for the latter, lessened the perceived significance of true allergy. Some commentators see claims of dietary intolerance as a modern manifestation of regarding nature as good or bad or an underlying fear that modern life is toxic. It is undeniable that if dietary and specialist allergy advice were more high-regarded and available in the UK then patients might feel that GPs are able to "understand their problems" and GPs might have clearer information on which to found recommendations rather than reassurance which may not help or the claim that "it is all in your mind".

Allergy has the potential to kill and allergies must be treated with respect. Allergies must have clinical assessment and management.

The picture is less clear for intolerances. It may be very unwise to restrict your own or a child's diet on the basis of scientifically-dubious tests and in the absence of a clinical assessment. There is some speculation that restriction might even contribute to later sensitivities for a child if there are no appropriately low-level challenges to the immune system. There seems to be little value in test results that are not grounded in science and may imply the need for dietary-restrictions or allergen-avoidance that may have such a significant impact on your well-being or that of a child.

Earlier related posts: Asthma and Food Allergies: Fashion or the New Form of Spiritual Re-Awakening?
Some Sticky Numbers and Comparisons for Food Allergy and Intolerance

For more information about the image used in the illustration, click on it or visit the detail on Flickr.

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Sunday, February 18, 2007

Paediatric Grand Rounds Wants Your Post, Please

Mock-up cover for Standing Baby magazineYes, it is out with the begging bowl, as I shamelessly rattle the post collection bag and ask you for your contributions to Paediatric Grand Rounds. As you can see from the magazine cover, we are open to conventional and more off-beat topics.

Paediatric Grand Rounds will be held next Sunday over at Allergy and Asthma Source. Please send along your links to Dr. de Asis at
deasis80[AT] yahoo [DOT] com.

Her deadline is Feb. 23, 2007 (ET) 12 midnight ET.

BritMeds 2007 (7) Is Up!

BritMeds 2007 logo with a Union Jack backdropOver on NHS Blog Doc, Dr. Crippen has been trawling British Blogs for posts on a medical topic for BritMeds.

It is a rich blend of posts that covers bullying politics, medical ethics, economics grumbles and general weirdness. Mix all of these with an insight into public health development and political machinations, and we have a thoroughly entertaining compilation.

Friday, February 16, 2007

Why IgG Testing for Food Intolerance Is Not As Simple As ABC or Doh Ray Mi

Cat with rifle poised at a window. The caption reads When all else fails, vote from the rooftopsWhat I know about the scientific validity of IgG testing to diagnose food intolerance could be written on a postcard leaving plenty of room for the address and stamp. I'm just mentioning this because it may be time for authors' competing interest declarations to be supplemented with a statement of scope of knowledge/ignorance/belief.

I've been prompted to consider the need for this statement by Patrick Holford's theatrical outrage about BBC Watchdog's Dirty Allergy Trick* (NB, the original article has been removed, I shall do my best to keep up with other links to it). A healthy volunteer participated in three food allergy/intolerance tests – two VEGA tests (conducted at different times and with different operators), a hair test, and two YorkTest IgG Food Intolerance tests (he submitted two blood samples under different names).

The hair and VEGA tests yielded long lists of foodstuffs that should be avoided. The investigative team highlighted the unreliability of the two VEGA tests that yielded different results. The team mentioned that the Yorktest results differed, but far less egregiously than the VEGA tests. According to Holford, this outcome was equivalent to a " [t]humbs up for Yorktest".
The expert they used to pass judgement said that there had been only one study on IgG as a basis for allergy! That is plain deception. If you go into Medline, the on-line database of published research and put in IgG you’ll find 139,473 referenced studies. If you narrow down to IgG + food intolerance it list 85 studies. I referenced 115 studies in my book Hidden Food Allergies (Piatkus). The evidence for IgG antibody reactions as a basis for food intolerances continues to grow, including well designed randomised controlled trials, however, some health professionals just haven’t kept up to date. Perhaps it’s because a ‘home test’ takes the power away from the professional and puts it in your hands.
Should the 'expert' hang his head in shame? Should I break out the sackcloth and ashes for failing to be convinced by both Patrick Holford's erudite assertions and expert support for IgG testing, as listed by YorkTest? Among the experts, Muriel Simmons of Allergy UK is quoted as saying:
The clinically proven YORKTEST Food Intolerance Test and back up support offered to patients provides a wonderful service for food intolerance sufferers worldwide.
To the comparatively uninformed, such as myself, it seems as if Patrick Holford conflates allergy and intolerance, but he endorses the tests enthusiastically:
The vast majority of food allergies happen because individuals produce IgG antibodies to specific foods. If symptoms, pain or energy levels come and go for no obvious reason, then you may have a hidden food allergy or intolerance. A simple YORKTEST Laboratories IgG food allergy home test provides clear, laboratory analysed, scientific results.
I'm going to deal with these endorsements separately. Although it isn't clear from the quotation attributed to her, Muriel Simmons may be relying upon a study into IgG testing and an elimination diet in a group of people with irritable bowel syndrome (IBS). In the abstract for that paper, the authors quite properly restrict the scope of their conclusions:
Food elimination based on IgG antibodies may be effective in reducing IBS symptoms and is worthy of further biomedical research. [Emphasis added.]
This is in stark contrast to some of the authorities who lend their YorkTest-styled expertise to endorsing the tests as valid for "food intolerance": a catch-all term that can encompass more than 100 symptoms of varying severity.

Dr. Hunter, who has research interests and publications in IBS, made the following comments about the value of the findings from that study: Food Elimination in IBS: The Case for IgG Testing Remains Doubtful.
The percentage of patients showing substantial benefit from this diet is disappointing. In studies using a well conducted and rigorous elimination diet, the "number needed to treat" is between 1.5 and 2.2 [refs]. The "number needed to treat" in this study was 9. (The value of 2.5, calculated on the basis of those who fully complied with the diet, abrogates the intention to treat principle.)

This seemingly poor response to an IgG based diet confirms the widely held view to date that IgG testing for food intolerance is not of value. [refs] These results suggests that if IgG testing identifies food intolerances at all, it does so fortuituously and with an apparent low degree of accuracy.
Hunter further argues that the study was premature because it is not yet possible to answer the basic research question: "do high levels of IgG against a food predict an adverse reaction to that food?". Three of the four authors of the original paper replied to Hunter and elaborated their view on how their findings should be interpreted (scroll down).
[I]t is entirely possible that IgG antibodies may be important in IBS, where we now know that there is an inflammatory component in some cases, whereas they may not be relevant in food intolerance in general. Furthermore, it is likely that only a subset of patients are likely to have an immuno-inflammatory basis to their condition and these might be the very individuals who respond to dietary exlusion based on IgG antibodies. This would fit with our results where only a proportion of patients responded despite all having antibodies. This, of course, limits the specificity and usefulness of the test unless such subgroups can be indentified beforehand. We should also bear in mind that an immunological reaction in the gut, as opposed to other forms of food intolerance, may make the gut more susceptible to other perturbing stimuli, such as stress, rather than necessarily causing symptoms directly. [Emphases added.]
Unlike YorkTest and some of the experts who endorse the scientific validity of their tests, Prof. Whorwell and his colleagues are punctilious in limiting the scope of their findings to IBS: they acknowledge the relevance of other factors, such as stress, in IBS and are open to the possibility that their findings "may not be relevant in food intolerance in general".

On his own site, Patrick Holford ascribes a far greater diagnostic role for YorkTests and praises their "solid science":
The best tests for food and chemical allergies and intolerances measure the presence of antibodies in the blood called immunoglobulins...
My favourite laboratory is Yorktest Laboratories whose tests are clinically validated...
Yorktest have also carried out a number of ‘double-blind’ trials on their IgG test and have solid science to back up their claims of effectiveness.
Prof. Whorwell and his colleagues made no such claims, so Holford's confident claims presumably arise from that overwhelming number of studies on Medline. And, yes, it is true, if you put IgG into Entrez Pubmed, you will have a huge number of hits returned. I did this, today, and in the 5 weeks since Holford did his search, the number has grown to 140032. Narrowing the search to IgG + food intolerance yielded 86 results: less than 140032 but still a substantial body of research.

Except...not all of those 86 results are relevant. I am both unconvinced of the relevance, and unmoved by the implied plight in Longterm effects in neonatal basal forebrain cholinergic lesions on radial maze learning and impulsivity in rats; I'm similarly stumped by the relevance of Leptin administration prevents spontaneous gestational diabetes in heterozygous Lepr(db/+) mice: effects on placental leptin and fetal growth.

At the risk of appearing specie-ist, I restricted my exploration to those papers that seemed to involve humans or readily generalisable to them. A number of the papers involved variations on the word unproved in their titles; see examples here, here and here. Concentrating on these papers seemed unfair, so I consulted a selection of the others. For reasons of delicacy, I thought that I should likewise ignore papers with, e.g., unreliability in the title.

Working through the studies that remained, most of the authors (like Whorwell and colleagues) were scrupulous in defining the limits of the relevance of their findings to populations with IBS or infants with milk intolerance rather than claiming wider relevance in the field of food intolerance or validation for the IgG tests. Even when authors explored a broader remit, e.g., Alternative Tests in the Diagnosis of Food Allergies, they reported findings that do not support Holford's claims:
We reviewed the scientific evidences of these tests (specificity, sensibility, rationale, reproducibility). According to most studies none of them had to be recommended as useful for the diagnosis of food allergy or intolerance. Physicians should alert patients about the risk of an indiscriminate use of these test in the diagnosis of food allergy. In fact the use of an incorrect diet could be dangerous, particularly in childhood, as recently shown.
Other researchers analysed IgG levels in blood from young, healthy, male volunteers with no previous signs or history of food allergy. Their findings do not support Holford's claims:
Common occurrence of asIgG-4 against food allergens in healthy persons (without any symptoms which could suggest allergy or food intolerance) argues against the possible participation of these antibodies in the pathogenesis of food allergy.
Holford claims that he refers to 115 studies in his book; presumably these are supportive studies. However, it is implausible that many of these studies are drawn from the peer-reviewed studies listed in the Entrez PubMed search. Remember that Holford accused the Watchdog team of a "slight [sic] of hand" yet he has referred to the existence of a vast number of papers as if they are relevant and support his claims.

I would emphasise that I am using the literature search terms that Holford cited to bolster his criticism of the judgment of the Watchdog expert and his attack on the Watchdog team that prompts him to use phrases such as "dirty allergy trick" and "plain deception". Holford has recently compared his own qualifications, knowledge and expertise with that of Dr. Ben Goldacre, believing that it is Goldacre who comes off worse for the comparison. He vaunts his
30 years researching, teaching, writing and practising nutrition.
I admit the limitations of my knowledge of these areas, however, I do not think that even a cursory examination of the research literature supports Holford's claims for the "sound science" of either IgG testing or Yorktests in the diagnosis or validation of food intolerance. Perhaps the matter would be clearer to me if Holford had listed the supportive studies rather than sent me off on a wild-goose chase through the literature.

For a wider discussion of the poverty of evidence behind food intolerance, see Sandy's well-referenced, Fear of foods, contaminants and modern life. She quotes some disturbing findings:
Rona and Chinn found that around one half of parents who thought that their child was food allergic or intolerant altered their child's diet, but only one third sought medical advice, and that some children were 4 cm shorter than controls. Unnecessary environmental and chemical avoidance, creating a perception of organic illness where none exists, or advising physical interventions when psychosocial factors are the source of symptoms, can impact on employment and social functioning.
If the experts who provided testimonials to Yorktest meant to limit the scope of their support to the usefulness of IgG testing in guiding food elimination diets in people with IBS, then they should have stated this clearly. If they believe that research findings can support a more generous interpretation than their own authors would assign to them, then it would be helpful if they stated their reasons for this. If there is "sound science" that confirms the value of IgG testing in diagnosing and confirming food intolerance then it would be a valuable contribution to the public debate if either the experts or the company marketing the test were to provide the references. Holford chooses to deprecate the knowledge of others:
some health professionals just haven’t kept up to date. Perhaps it’s because a ‘home test’ takes the power away from the professional and puts it in your hands.
However, until such time as I see these references, I will reserve my judgment as to which parties are indulging in a "dirty allergy trick" or "plain deception". The parents highlighted in the Rona and Chinn took their power into their own hands because they couldn't obtain formal help for their children's perceived food intolerances; as a consequence, those primary school children are shorter than their non-food-intolerant peers by an average 1.5 cm. Encouraging people to take tests that boost their empowerment and lead to restrictive diets can have consequences: it would be useful if the experts who endorse these tests and diets were explicit on this point.

*Edited 1 March It seems that Holford's article has been removed from the site. I have replaced that link with ones to sites that still have a copy. The original link was BBC Watchdog's Dirty Allergy Trick. At the time of writing, other copies are as follows: BBC Watchdog's Dirty Allergy Trick; Nutritional Therapy: BBC Watchdog's Dirty Allergy Trick; BBC Watchdog's Dirty Allergy Trick. If these links disappear then I shall put up a link to the cached version of the article.

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Wednesday, February 14, 2007

Wakefield's Latest Tent Mission on the Doctrine of Autism

Church sign reads, Autism Is TreatableDr. Andrew Wakefield has briefly visited the UK to headline at a new tent mission of Autism Is Treatable! Despite the paucity of evidence to support the articles of faith Wakefield has disseminated to his acolytes and followers, and indeed, the overwhelming evidence of multiple epidemiological studies, he preaches an unashamed gospel of biomedical experimentation on children with autism.

Parents shared "Stories of Hope and Success". Wakefield was supported by other speakers who offered their own transformative treatment modalities.
So these mavericks continue to circulate, paddling in the same scientific shallows, attending the same conferences and boasting connections with the same research institutes. They travel the world quoting each other in circular support, reinforcing a fringe belief in unproven interventions for autism and propagating the mistaken view that ordinary doctors are cowed by mysterious vested interests (pharmaceutical companies?) into not doing their best for children with autism.

Their harmful agenda is, regrettably, assisted by newspapers with acres of space to fill, who delight in feeding the middle-class paranoia over perfect parenting...

There is nothing wrong with a scientist pursuing a hunch, and everything right about parents wanting to do the best for their child. There is nothing even particularly sinister about Dr Wakefield gambling his reputation on an instinct. But there is something depressing beyond belief about a scientist who refuses to recant in the face of overwhelming opposing evidence.
At some point, it would be gracious if Wakefield acknowledged the harm that he has done to public health in the UK. The indefatigable Kevin Leitch has made his usual wise comments but some of the others are a little dispiriting in their unwavering support for Wakefield and his discredited claims. Nonetheless, it is refreshing to read coverage of Wakefield that is not hagiographic.

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A Miserable Day for Child Wellbeing in the UK But I Discover Hope for Their Creativity

Young man in a hooded top: with attitudeAttitude before platitudes.

There has been a lot of coverage of the UN report that puts the UK at the bottom of the league table for child wellbeing in 21 industrialised nations. The UN report has had a vast amount of air time and column inches; it is all throughly miserable reading and I can't bear to link to it. Suffice it to say that according to the UN's analysis, british children are unhappy, unhealthy, lonely, neglected, ill-educated...Pretty much, drag out your lexicon of condemnation and pick out all of the words that cause you to tsk or groan in despair.

Just when everything was encouraging me to google along the lines of "centuries of literature describe the wretchedness of today's youth", I've come across what may well be a piece of modern apocrypha that restores my hope. Even if the following technique isn't true, I admire the creativity that went into the story and the ingenuity of thinking up the technique to subvert electronic tagging.

A blogging Magistrate tells the story of a Prison Governor who visits schoolchildren in local schools to disabuse them of the notion that there is a cell-tacular glamour in prison life.
He found that he learnt quite a bit from the kids, including the technique for removing a tag without damaging it, so that your social life is not tiresomely disrupted by a mere court order. Apparently if you warm the bracelet slowly and carefully with a hair-dryer, the plastic softens enough for you to remove the tag and park it by the phone.
A few years ago, a friend who can become quite distressed about the poor state of science education in the UK, was caught between exasperation and amusement when his top-of-the-range, unbreakable bicycle lock was broken and his bike stolen. The thieves had broken the lock by applying liquid nitrogen to freeze it and then smashing it. He applauded the application of scientific knowledge as he bemoaned the purposes to which it had been put.

It may be a small thing, but I cleave to such ingenuity as hope for this generation who must be tired of hearing so many jeremiads about their health, future longevity, ability to form relationships and dearth of opportunities. I think that constantly promoting such a message is debilitating both for the children and the parents who provide the framework for their lives. I'm not declaring a manifesto of complacency because too many children are missing out on the benefits of living in a wealthy country. However, despite the media tolling of the anthem for a neglected and feral youth, I do not believe that they will inevitably die at an earlier age than their parents nor that there will be an increased incidence of chronic illness.

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Monday, February 12, 2007

PGR 1:22 Is Up!

Illustration of a heartPaediatric Grand Rounds 1:22 is up at Adventures of an Awesome Mom. Lissa has put together some interesting material about the heart, both in keeping with her own interests and experience and in honour of the PGR's proximity to Valentine's Day. Most of us did not manage to put together a heart-themed post (I didn't) but there is an interesting mix, as ever.

The next edition of PGR will be hosted by Dr. Lourdes de Asis at Allergy and Asthma Source (the next time that I remember my Blogrolling password, she will be linked in my sidebar). Clark is looking for more hosts of Paediatric Grand Rounds so please consult the schedule and volunteer your efforts.

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BritMeds 2007 (6)

BritMeds 2007 logo with a Union Jack backdropOver on NHS Blog Doc, Dr. Crippen has been trawling British Blogs for posts on a medical topic for BritMeds.

It is a rich blend of posts that covers bullying politics, medical ethics, economics and general weirdness. Mix all of these with an insight into public health development and political machinations, and we have a thoroughly entertaining compilation.

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Saturday, February 10, 2007

On Wanting to Vent My Rage Following Sloppy Journalism: Food Allergy and Intolerance

Cat with rifle poised at a window. The caption reads When all else fails, vote from the rooftopsRecently, I wrote up Allergy UK's successful promotion of Allergy and Intolerance Week in the UK. I was a little startled by some of the widely reported statistics about the incidence of food intolerance and its impact on people's lives. There were some truly harrowing pieces about the impact of food intolerance on the quality of life and some dispiriting numbers. I rather took it for granted that the journalists had done some checking into the source of the statistics and validated them.

It now seems as if I may have been rather naive. I am still trying to track the story because my emails have so far gone unanswered, but it seems as if those statistics may have been drawn from a collaborative study by Allergy UK and YorkTest (scroll down for the abstract). Those statistics seem to have been drawn from a postal survey of people who had already had IgG testing from York Test (and, presumably, paid for it which is a little unusual for a research study). Those of us who rely on journalists or the public domain don't readily know which of the tests (the sample kit, the 42 foods kit or the 113 foods kit) that participants had, but, digging around into the PR release for the study, I learn that it was the 113 test, which offers testing against 113 foodstuffs, consultation with a 'food nutritionist' and a year's membership of Allergy UK.
A postal survey, commissioned by Allergy UK, was carried out with 5,286 subjects reporting a wide range of chronic medical conditions, who had taken a food-specific IgG enzyme-linked immunosorbant assay blood test.
In addition to the widespread claims of illness related to food intolerance, the authors of this paper claim that:
[o]f patients who rigorously followed the diet 75.8 per cent had a noticeable improvement in their condition. Of patients who benefited from following the recommendations 68.2 per cent felt the benefit within three weeks. Those who reported more than one condition were more likely to report noticeable improvement. 81.5 per cent of those that dieted rigorously and reported three or more co-morbidities showed noticeable improvement in their condition. For those who dieted rigorously and reported high benefit, 92.3 per cent noticed a return of symptoms on reintroduction of the offending foods.
What fantastic results. I would really like to evaluate them but without the full paper it is impossible to gauge how many of the participants managed to follow the diet 'rigorously'. Nor can the casual reader understand what is meant by 'rigorously'. Is it somebody who avoids the red foods and rotates the yellow foods? Do people who avoid the red but eat the yellow as they wish fail to come into this category?
[T]he foods in the green section are all okay to eat freely, the foods listed in the yellow section should only be eaten every 4-5 days, and the foods in the red section are those you should avoid.
Despite the various claims to the contrary on the websites of both YorkTest and Allergy UK, it does not look like the notion of food intolerance is medically accepted, far less the existence of a blood test to identify the intolerance by measuring IgG levels.

The postal survey does not tell us what the respondents were eating before their intolerance testing. It would not be too difficult to imagine that people who are chronically tired or experiencing 'brain fog' might not prepare food from scratch on a regular basis. It is possible that the striking improvements in well-being might occur in anyone who shifts from a diet of processed food to home-prepared 'healthy' meals. The best way to test this would be to find a group of people who are chronically tired etc. but do not suggest food intolerance and to switch them to a more wholefood way of eating. Actually, that sounds like a number of diet makeover T.V. programmes which show startling results when people change their way of eating (although, to be fair, they usually start exercising as well).

The PR release for the study claims the following:
The new study...is the largest ever food intolerance study undertaken in the UK and reveals for the first time that over 60% of patients involved in the study had to endure over 3 years of NHS appointments, suffering and misdiagnosis before obtaining improvement through the food intolerance testing.

5200 people took part in the study and were treated for a wide range of mild and chronic illnesses. In addition, nearly a third of all patients received NHS treatment for over a decade without success. 32.4% of the sample showed they had suffered with their condition for over ten years before taking up a food intolerance health solution.

At the other end of the scale just 5% of patients had illnesses lasting from 1-6 months before using food intolerance and 22% were upto 35 months before seeking a non-NHS resolve via food intolerance testing.
Other reported findings in the study reveal:
  • Over 3 out of 4 patients get better from their original symptoms.
  • 68.2% of patients benefited within the first three weeks.
  • 9 out 10 patients had a return of symptoms when introducing offending foods back into their diet.
  • Many patients would rather have a dietary solution than taking medication.
  • Patients who reported more than one condition were most likely to report improvement.
  • On average, patients had symptoms for at least 10 years before taking up a food intolerance option.
I find these claims to be a little extravagant but who am I to snark that there are no objective measurements (no attempts to correlate with medical records) and the study covers a 3 month period.

In the absence of open access journals we rely upon journalists of various media to read and understand studies that are of general interest and to report upon them accurately. However, as Goldacre expresses it, although
newspapers like to fantasise that they are mediators between specialist tricky knowledge and the wider public...I wouldn’t be so flattering. In fact, if you have access to the original journals, you can see just how rubbish things can get.
Dr. Crippen has commented on a claim that Lightning Therapy transformed the life of a young woman with CFS/ME:
[i]f we can “cure” every ME patient in the country, or even some of them, with a three day course costing £600 we should start work on it tomorrow.
Well, according to this study, it looks possible to improve the health and quality of life for people with a number of hard-to-treat disorders such as CFS/ME, and I'm sure that the NHS would be able to license the technology or negotiate a volume discount deal. If it worked and the quality of the evidence were any better... It is a shame that claims like this pass unchallenged by journalists because it may lead people to think that the NHS has diagnostic techniques and treatments that it is withholding on a whim. Because after all, for the comparatively tiny sums of money involved and the appalling catalogue of human misery involved, and the economic argument that many people would have enhanced productivity or be removed from incapacity benefit, the failure to test or treat would have to be attributed to whimsical GPs rather than any other reason.

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Friday, February 09, 2007

The Duvet Diet: The Importance of Sleep Quality and Children

Cat lies on duvet: symbol of virtue and idleness and simple pleasure. Caption exhorts us to smell the duvet
When The Times ran an article provocatively entitled The Duvet Diet I feared that it was going to be one of those puff pieces for a magnetised mattress pulling the fat from your body while you slept under the thermogenic stimulus of an essential-oils-impregnated-duvet. So, I was both abashed and relieved that the article stressed that sleep is essential to our physical, cognitive and emotional well-being: and that it has a profound impact on our metabolism and physiology.

Young boy sleeps in the back of a carDr. Taheri of the University of Bristol is probably even now attaining cult status in playgrounds for his advice that children should be allowed to sleep uninterrupted (he wisely doesn't get into the argument of when the bedtime should be). Dr. Taheri is particularly interested in whether the sharp increase in teenage obesity is related to the fact that teenagers biologically need so much more sleep than modern lifestyles allow them to have. The article quotes Dr. Taheri:
How much sleep we have affects our IQ, our suicide risk, our chance of substance abuse and our weight...If we don’t take it seriously, we will pay the consequences.
Update October 19, Dr. Taheri has published a review of studies that link sleep deprivation and excess bodyfat in children and teenagers. He suggests some tips to improve that quantity of sleep although he does not address the quality of sleep or sleep-disordered breathing in this review.

Young man soundly asleep over his laptopA bald summary of the theoretical underpinning of the Duvet Diet is that lack of sleep affects the hormones that influence appetite: so, for some people
less sleep=hormone disruption=greater appetite=weight gain
Several hormones contribute to the rise in appetite. The stress hormone, cortisol, is probably the best-known of these. Cortisol levels follow a fluctuating rhythm throughout the day. Cortisol levels peak somewhere between late-morning and noon: thereafter they fall, and should reach low levels before falling asleep. There is some speculation that there is a substantial fall in cortisol levels between 2 and 4 a.m. that is linked to the number of asthma exacerbations that happen between midnight and 8 a.m.. However, the mechanism of nocturnal exacerbation of asthma is not clearcut: there are probably multiple (perhaps synergistic) factors that make a contribution.

Middle-aged man with an apple tummy, asleep on a couch with small boy asleep against himEve Van Cauter has reported studies that show short sleep duration in young, healthy men is associated with decreased leptin levels, increased ghrelin levels, and increased hunger and appetite, and cortisol disturbances that influence the ability to cope with stress and also promote the laying down of a personal duvet of body fat. An interesting speculation here is that sleep apnoea is typically found in middle-aged, overweight men who have increased their collar-size (implying more body fat around the neck): if sleep disordered breathing (SDB) has been present for some time, it may have contributed to the weight gain, as well as being exacerbated by that weight gain. A similar hypothetical vicious circle may be present in morbidly obese children with SDB.

A recently reported longitudinal study* found that inadequate sleep has a negative effect on a child's social and emotional well-being as well as school performance: the results also highlighted a link to being overweight. After analysing 5 years-worth of sleep diaries (hours asleep, bed times and wake times) and tracking height and weight logs, the research team found that even after adjusting for a series of factors (e.g., race, socio-economic status, eduaction) the children who logged less sleep were more likely to be overweight and have higher BMI than those who recorded more sleep.

Paediatric sleep experts recommend:
  • children aged 5 to 12 should sleep for 10 to 11 hours a night
  • adolescents should sleep for 8 to 9 hours
However, in this study, children aged 7 on average got less than 10 hours of sleep on weekdays and at age 14 got 8.5 hours of sleep on weekdays. The authors report that an extra hour of sleep reduces the likelihood of being overweight from 36 percent to 30 percent in children ages 3 to 8, and from 34 to 30 percent in those ages 8 to 13. The authors suggest that:
[i]f our results represent a true causal relationship between sleep and weight, encouraging parents to put their younger children to bed earlier at night and allowing both younger and older children to sleep longer in the morning, as well as urging school districts to avoid very early school start times for later elementary and middle school aged children, might represent an important and relatively low cost strategy to reduce childhood weight problems.

Cranky child with a barrage of speech bubbles saying, No; Whatever, Don't make me screamThere is a lot of evidence that highlights the importance of sleep's contribution to allostasis and therefore, wellbeing. Salvador Minuchin famously remarked that "behavioral events among family members can be measured in the bloodstream of other family members".** It seems as if that could also be adapted to "behavioural events among family members can be measured in the diagnoses of other family members". The Times carried a summary of El-Sheik's research into sleep quality in children. The more that children are exposed to parental conflicts, the worse they sleep. And, the worse children sleep, the more likely they are to be tired when awake, have difficulty focusing and be irritable and badly behaved. These are some of the behaviours that could make a contribution to a diagnosis of hyperactivity behaviour or ADHD. The tiredness-related behaviours would also mean that the children fulfil the diagnostic requirement of ADHD to have the behaviour documented in a variety of settings. And, as the children would be tired for most of the day, I think that that criterion would be met. Children with ADHD may have SDB as a separate issue, but there is increasing speculation that some of the children with SDB have been mis-diagnosed with ADHD or hyperactivity behaviour.

Recent sleep research in both adults and children shows that sleep quality has a tremendous impact on physical and emotional well-being and on our cognitive performance. The effects of poor sleep quality go beyond feelings of fatigue; they are said to encompass raised blood pressure, metabolic changes linked to metabolic syndrome, increased likelihood of diabetes etc.

For the present, it does look like a Duvet Diet of adequate sleep and good nutrition might be of importance to establishing a firm foundation for children's health. Poor sleep quality and its plausible contribution to inactivity and poor food choices may mean that the foundation of good health is gradually eroded and may collapse over time.
A bank of sand has a large hole caused by wind erosion: only a small bridge of sand remains at the top to prevent collapse
*Snell EK, Adam EK, Duncan GJ. "Sleep and the Body Mass Index and Overweight Status of Children and Adolescents." Child Dev. 78;1.
**These examples are taken from Principles of allostasis: optimal design, predictive regulation, pathophysiology and rational therapeutics (pdf file) by Peter Sterling, in Allostasis, Homeostasis and the Costs of Adaptation, (ed) J. Schulkin. CUP. 2004.

This post is updated from an earlier one as I'm writing various applications.

For more information about the images used in the illustrations, click on them to see the detail about the contributors on Flickr (where they are from Flickr-the cartoon isn't).

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