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Press releases Friday 23 May 2008

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(1) Oral HRT more than doubles the risk of blood clots
(2)Will polyclinics deliver real benefits to patients?
(3)A trial of removing food additives should be considered for hyperactive children

(1) Oral HRT more than doubles the risk of blood clots
(Research: Postmenopausal hormone therapy and risk of venous thromboembolism: a systematic review and meta-analysis)
http://www.bmj.com/cgi/content/full/bmj.39555.441944.BE
(Editorial : Type of hormone therapy and risk of venous thromboembolism)
http://www.bmj.com/cgi/content/full/bmj.39556.666944.80

Hormone replacement therapy (HRT) given in skin patches may cause fewer blood clots than HRT given orally, according to a report published on BMJ.com today. Furthermore, women who take the oral form of HRT more than double their risk of developing a blood clot, say the authors.

HRT is regularly prescribed to women suffering from the effects of the menopause. Previous studies have shown that taking HRT is associated with an increased risk of venous thromboembolism (VTE), a blood clot in the vein which can be fatal.

But until now no systematic meta-analysis has assessed how much of an increased risk there is, or whether the risk varies according to the type of HRT treatment a woman is taking, such as skin patches compared to oral HRT.

The researchers reviewed data from eight observational studies and nine randomised controlled trials. They found that women taking the oral form of the drug were between two and three times more likely to develop a blood clot, and that the risk was significantly higher during the first year of treatment. Past treatment was not associated with increased risk. If a woman was overweight or genetically pre-disposed towards suffering from blood clots then the risk increased further.

Importantly, HRT given in patch form showed no significant increase in the risk of VTE. However, the authors warn that the results should be treated with caution as the data is from observational studies - no trials have yet investigated the effects of oestrogen patches on the risk of VTE.

They suggest that the reason for the difference in risk of VTE between the oral and the patch form might be due to the different way oestrogen is absorbed into the blood stream. When taken orally, oestrogen enters through the digestive system and the researchers say this process, by affecting the liver, might impair the balance between clotting and anti-clotting.

Overall, the results suggest that HRT patches might be safer than oral HRT with regard to thrombotic risk.

Since VTE has become the major adverse effect of short term oral oestrogen therapy, reducing thrombotic risk could have important clinical implications. However, the authors conclude that more research is needed to confirm the apparent safety of oestrogen patches with respect to thrombotic risk.

Helen Roberts from the University of Auckland discusses the need for more research into the association between VTE and oestrogen patches in an accompanying editorial.

"In the meantime, we can advise healthy menopausal women, aged 50-59, that the risk of VTE with oral preparations is 11 additional cases per 10 000 women per year for combined therapy and 2 additional cases per 10 000 women per year for oestrogen only", she concludes.

Contacts:
Pierre-Yves Scarabin and Marianne Canonico, Cardiovascular Epidemiology Section, Paul Brousse Hospital, France
Email: scarabin@vjf.inserm.fr
Editorial: Helen Roberts, Senior lecturer in women’s health, University of Auckland, Auckland, New Zealand
Email: h.roberts@auckland.ac.nz

(2) Will polyclinics deliver real benefits to patients?
(Head to head: Will Polyclinics deliver real benefits to patients?)
Yes:
www.bmj.com/cgi/content/extract/336/7654/1164
No:
www.bmj.com/cgi/content/extract/336/7654/1165
(Review: Polyclinics: haven't we been there before?)
www.bmj.com/cgi/content/extract/336/7654/1161

Government proposals to establish polyclinics are intended to reshape NHS services, but will they deliver the more patient centred care they propose, or do they risk becoming an expensive mistake?

Michael Dixon, Chair of the NHS Alliance and Stewart Kay, Chair of the Londonwide Local Medical Committees (LMC's), debate the issue on BMJ.com today.

Polyclinics will offer a one stop shop. Rather than replacing existing generalist care, they will extend it by bringing GP practices and other secondary care services together so patients can benefit from a greater range of cost effective, accessible, and better coordinated care, argues Michael Dixon Chair of the NHS Alliance.

In many cases general practices will stay where they currently are as part of a "virtual polyclinic".

The key to the success of these practices will be their development by frontline practitioners and local people. The implementation of the polyclinic idea should not be "a sequence of orders from strategic health authority to primary care trust but a process of support for local practices to achieve their own integrated vision", he writes.

Dixon believes that the scepticism and negative press surrounding polyclinics is misplaced and results partly from the connotation of the term "polyclinic" rather than a problem with the basic concept. The word "clinic" implies a very biomedical approach, he says, but the proposed primary care polyclinics are about personal relationships, self help, personal health, and improving community health.

Changing the name from polyclinic to, for example, "integrated centre" would make it clearer what the polyclinic model is actually about, he claims.

In addition, he says, recent media stories of GPs being forced into submission and reports of growing divisions between managers and clinicians, has resulted in misinterpretation, exaggeration and conspiracy theories.

The idea behind polyclinics may have been "lost in translation", but that does not mean that the basic concept is unsound, he concludes.

But Stewart Kay, Chair of the Londonwide LMC's, argues that better value would be provided by investing in the current model of general practice that already provides a wide range of services to diverse communities. The polyclinic model is, he says, expensive, based on untested assumptions, and potentially harmful to existing practices.

He points out that the smaller and more local traditional general practice - which has evolved with its community - can better serve the old, young and vulnerable, as well as adapt better to meet the different cultural and language needs of a small locality. Continuity of care and personal care are more difficult to provide in large units.

Furthermore, he says, because 80-90% of medical encounters happen in general practice, it is vital that this service stays local to patients, and is not moved "to some arbitrarily situated polyclinic." Because there are few sites of suitable size available in London to accommodate a polyclinic, it has been suggested that old hospital and community clinic sites be redeveloped - but these will rarely be well situated for patients, he claims.

Recent data from 1562 patients across 24 Primary Care trusts suggests that only 1 in 10 patients favour the Polyclinic model over their current practice.

Kay believes that the suggested components of the Polyclinic are already provided by general practice (community services, minor procedures, extended hours, health education), or easily accessible elsewhere (urgent care centres, outpatients, diagnostics). The solution is to invest in the development of traditional general practice, he concludes.

The idea of the polyclinic is not new, argues Professor Virginia Berridge from the London School of Hygiene and Tropical Medicine, in an accompanying editorial.

Despite a long and interesting history in London, and in the discussions of the early NHS 60 years ago, polyclinics failed to reach their full potential as a result of political backtracking over cost, and opposition from GPs who saw their status, income, and relationship with patients threatened. However, GPs have been enthusiastic about them in the past and could be again, writes Berridge.

Could the polyclinic be an idea whose time has now come, she asks.

Contacts:
Michael Dixon, Chair, NHS Alliance, Nottinghamshire, UK
Email: michaeldixon@nhs.net
Stewart Kay, Chair of the Governance Board of the Londonwide Local Medical Committees, London, UK
Email: stewart.kay@gp-G85012.nhs.uk
Review: Virginia Berridge, London School of Hygiene and Tropical Medicine, London, UK
Email: virginia.berridge@lshtm.ac.uk

(3) A trial of removing food additives should be considered for hyperactive children
(Editorial: Food additives and hyperactivity)
www.bmj.com/cgi/content/full/336/7654/1144

A properly supervised trial eliminating colours and preservatives from the diet of hyperactive children should considered a part of the standard treatment, says an editorial in this week's BMJ.

Although a substantial body of evidence shows a link between attention deficit hyperactivity disorder (ADHD) and artificial food colourings and preservatives, removing them is still considered as an alternative rather than a standard treatment for ADHD, writes Professor Andrew Kemp from the University of Sydney.

In contrast, despite a lack of evidence for its effectiveness, the use of alternative medicine is widespread - up to 50% of children attending tertiary children's hospitals in the UK and Australia have used it in the past year.

Of the three main treatments for ADHD in children - drugs, behavioural therapy, and dietary modification - only drugs and dietary modification are supported by data from several trials. Yet, behavioural therapy, which has no scientific evidence base, is still thought of as necessary for "adequate treatment", he says.

So why, despite evidence to the contrary, does the removal of food additives remain an alternative rather than a standard part of treatment for ADHD, asks Kemp?

Data published in 2007 showed that normal (not hyperactive) children were significantly more hyperactive after they ate a mixture of food colourings and a preservative (sodium benzoate), with obvious implications for children with ADHD.

In light of these findings, the European Food Safety Authority (EFSA) reviewed the evidence linking preservatives and colourings with hyperactive behaviours from 22 studies between 1975 and 1994 and two additional meta-analyses.

16 of the studies reported positive effects in at least some of the children. However, the EFSA pointed out that hyperactivity has a wide range of social and biological causes, and exclusively focusing on food additives may "detract from the provision of adequate treatment" for children with the disorder. But, argues Kemp, to discount the accumulating evidence of dietary factors may also do this.

Increasing numbers of children are taking drugs for hyperactivity - 2.4% of children in the state of Western Australia. Removing colours and preservatives is a relatively harmless intervention, so a properly supervised and evaluated trial period of eliminating them should be considered as part of the standard treatment, he concludes.

Contact:
Andrew Kemp, Children's Hospital at Westmead, University of Sydney, Australia
Email: andrewk5@chw.edu.au

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