Misrepresenting the York fluoride review

By Ken Perrott 16/06/2015


I have noticed a few “Letters to the Editor” and social media comments lately misrepresenting the “York review” on fluoridation so looked into the background of some of these claims.

The “York review” (McDonagh, et al., 2000) is one of the earliest authoritative and comprehensive reviews of the scientific literature related to fluoridation and resulted from a request by the UK Department of Health for:

“a systematic review of the evidence for the safety and effectiveness of water fluoridation based on the currently available evidence from population-based studies.”

As a systematic review it is a valuable resource for decision-makers so this review – together with later and more comprehensive reviews – is usually accepted as one of the most reliable sources of evidence for local bodies considering fluoridation  issues. However, this very authority leads to its misrepresentation by activists.

We are used to activists misrepresenting the evidence contained in such reviews, but I want to comment on the way anti-fluoride propagandists attempt to present the review authors as supporting anti-fluoride positions. In particular, the way they use quotes from anti-fluoride people who have some tenuous connection to the review. These quotes are presented as authoritative, consistent with the reviews findings and with the implications the people quoted were authors  or members of the York Fluoride Systematic Review Team – when they were not.

Review Team & Advisory Panel

The York Fluoride Systematic Review Team were the authors of the report. These authors and affiliation are:

  • Jos Kleijnen, NHS Centre for Reviews and Dissemination, York, UK
  • Marian McDonagh, NHS Centre for Reviews and Dissemination, York, UK
  • Kate Misso, NHS Centre for Reviews and Dissemination, York, UK
  • Penny Whiting, NHS Centre for Reviews and Dissemination, York, UK
  • Paul Wilson, NHS Centre for Reviews and Dissemination, York, UK
  • Ivor Chestnutt, Dental Public Health Unit, Cardiff, Wales, UK
  • Jan Cooper, Dental School, University of Wales College of Medicine, Cardiff, Wales, UK
  • Elizabeth Treasure, Dental School, University of Wales College of
    Medicine, Cardiff, Wales, UK

However, an advisory board was also appointed. This included representatives from “both sides of the fluoridation debate” as well as including neutral people. According to Richards et al., (2002):

“Although the advisory panel and review team agreed the results of the review, agreement was not reached about the conclusions or, more importantly, the implications of the review.”

Hardly surprising given the differing views on the issue. This article adds:

“Parties on each side of the controversy were reluctant to abandon their previous positions and endorse the review result whole-heartedly.”

The Systematic Review Advisory Panel members were:

  • Chair: Trevor Sheldon, York Health Policy Group, University of York, York, UK
  • Earl Baldwin of Bewdley, House of Lords, London, UK
  • Iain Chalmers, UK Cochrane Centre, Oxford, UK
  • Sheila Gibson, Glasgow Homeopathic Hospital, Glasgow, Scotland, UK
  • Sarah Gorin, Help for Health Trust, Winchester, UK
  • Mike Lennon, Chairman of the British Fluoridation Society, Department of Clinical Dental Sciences, University of
    Liverpool School of Dentistry, Liverpool, UK
  • Peter Mansfield, Director of Templegarth Trust, Louth, UK
  • John Murray, Dean of Dentistry, University of Newcastle, Newcastle
    upon Tyne, UK
  • Jerry Read, Department of Health, London, UK
  • Derek Richards, Centre for Evidence-Based Dentistry, Oxford, UK
  • George Davey Smith, Department of Social Medicine, University of Bristol, Bristol, UK
  • Pamela Taylor, Water UK, London, UK

Readers will see the mixed nature of this group so won’t be surprised there were fixed views which prevented their endorsement of the review findings and conclusions.

Opportunist quoting of minority views

Anti-fluoridation propagandists have made much of quotes from 2 advisory panel members – people who were not authors of the review and could not represent the review itself.

york_chairman_quote

Out of context quote from anti-fluoride site No Fluoride.

Professor Trevor Sheldon has made a statement emphasising the provisional nature of the reviews findings, commenting on the poor quality of much of the research of health aspects and stressing the limitations of the review and need for further work. His statement recognised  that fluoridation is effective at reducing tooth decay The quality of research on health effects has also improved in recent years. However, anti-fluoride people use the quote in attempts to undermine research showing the efficacy of fluoridation and the lack of harmful effects. It is more correct to say, as Newton et al., (2015) did recently:

“In general, the literature suggesting adverse health effects of fluoridation is characterised by poor-quality studies that do not adequately adjust for potential confounding variables.”

Please note, Sheldon was a member of the Advisory panel and not an author of the review.

Another quote which has been rehashed recently by activists is from Advisory panel member Peter Mansfield:

“No physician in his right senses would prescribe for a person he has never met, whose medical history he does not know, a substance which is intended to create bodily change, with the advice, ‘Take as much as you like, but you will take it for the rest of your life because some children suffer from tooth decay.’”

Users of the quote imply he was an author of the review report – for example “Mansfield took part in the University of York (in York, England) review of public water fluoridation in 2000.” He did not. He was merely a member of the Advisory Panel representing the views of anti-fluoridationists. Have a search for him on the internet (he is the Director of Templegarth Trust, Louth, UK) to get a picture of his alternative health views.

Conclusions

In  their article about the York Review Richards et al., (2002) indicate that this early review identified problems with review processes and existing knowledge which future work would overcome:

“Future research can be more efficient and sharply focused as a result of open reviews of this kind. A consensus on future research priorities was one result of this review. The eventual findings of future work are more likely to be debated rationally and achieve wide consensus than if the review had not taken place.”

Anti-fluoride propagandists are simply taking advantage of those early issues, and dishonestly implying that they out-of-context quotes they use were made by authors of the York review when they weren’t.

References

McDonagh, M. S., Whiting, P. F., Wilson, P. M., Sutton, a J., Chestnutt, I., Cooper, J., … Kleijnen, J. (2000). Systematic review of water fluoridation. BMJ (Clinical Research Ed.), 321(7265), 855–9.

Newton, J. N., Young, N., Verne, J., & Morris, J. (2015). Water fluoridation and hypothyroidism: results of this study need much more cautious interpretation. Journal of Epidemiology and Community Health, 69(7), 617–8. http://doi.org/10.1136/jech-2015-205917

Richards, D., Mansfield, P., & Kleijnen, J. (2002). Systematic review in scientific controversy: the example of water fluoridation, an open access reviewEvidence-Based Dentistry, 3, 32–34.

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