|
27th Jan 2001: Financial
Times
Fluoridation findings set
teeth gnashing
By Jerome Burne,
Financial Times, 27-01-2001
How you feel about
a hell-fire preacher being caught with his trousers
down depends on whether you are a member of his
church. For the faithful it's shocking, for
outsiders maybe merely amusing. The sight of doctors
refusing to take their own medicine evokes similar
emotions, which is why health campaigner Edward
Baldwin (the Earl Baldwin of Bewdley) and Trevor
Sheldon, of the Department of Health Studies at York
University, are outraged.
They believe they
have clear evidence that top medical organisations
have been playing fast and loose with scientific
evidence, failing to apply the rigorous standards
they require of others to their own pet projects.
"It is particularly
worrying that statements that mislead the public . .
. have been made by the British Dental Association
[and] the British Medical Association," writes
Sheldon in a letter to MPs. "Anyone who considers
this report a ringing endorsement is either
dishonest, a fanatic or scientifically illiterate,"
says Baldwin.
The report in
question is one published last October into the
fluoridation of the UK's water supplies. The benefit
of putting extra amounts of the mineral fluoride
into drinking water has been the subject of an
acrimonious and heavily polarised debate for more
than 50 years. The first community to do it was
Grand Rapids, Michigan, in 1945. Supporters claim it
is a cheap and effective way of improving the
quality of a nation's teeth, while opponents declare
there is little evidence that it is effective and
plenty that it is hazardous.
More than 3,000
studies have been published on various aspects of
the debate and both sides can cite numerous ones in
their favour, but neither side has been able to
deliver the knock-out paper. The big medical and
dental associations on both sides of the Atlantic
have long been supporters, and for years the British
Dental Association, the British Medical Association,
and allies such as the British Fluoridation Society
have been pushing the UK government to take a more
pro-active line.
At the moment,
fluoride is added to 10 per cent of UK water,
compared with 62 per cent in the US, but recently
the government has been considering giving local
councils powers to compel water authorities to add
it. The only European country to have a nationwide
scheme is Ireland, which also has a vociferous
anti-lobby; its most recent coup was the discovery
that the fluoride put in Irish water is actually a
cocktail of chemicals, including arsenic and lead,
that is a by-product of fertiliser manufacture.
Denmark, Finland and Germany have all tried
fluoridation and abandoned it, while France has
consistently decided against it.
So to handle this
contentious issue, in 1999 the government ordered a
review of the evidence. The National Health Service
Centre for Reviews and Dissemination at York
University was charged with answering such basic
questions as: Does it work? Is it safe? Does it help
to close the dental health gap between rich and
poor? Baldwin, a long-time campaigner against
fluoridation, was on the advisory committee.
To understand why
he and others involved in the review are so outraged
at what happened when they produced their report
last October, it is necessary to explain just what
the committee was doing.
The systematic
review is at the heart of modern evidence-based
medicine. It's not like a royal commission where you
call witnesses and hear evidence. It's designed to
do a very specific job - a sort of court of appeal
for the medical profession.
The pace of modern
research is so fast that no doctor can keep up with
all the latest drugs and treatments, and the
evidence for and against them. And even if you had
time to check through all the research, how do you
judge between conflicting findings? The systematic
review was devised to solve this problem.
First, a team of
researchers trawls through the literature to find
any relevant trials and then - and this is the
important part - it ranks them in terms of how
reliable they are. For instance, the results of
carefully controlled trials with a large number of
subjects, preferably "blinded" so no one knew who
was getting the treatment, get a higher rating than
reports of what happened to a few patients. Then the
reviewers reach a conclusion - this works, this
doesn't, or maybe (the evidence isn't good enough to
decide either way).
This is what the
National Institute for Clinical Excellence uses to
decide if treatments are worth paying for and it is
a technique that provides some sort of objective
overview of the claims and counter-claims whirling
around fluoride. A systematic review isn't just
another bit of evidence, it's a carefully considered
judgment on the whole topic. So what happened when
the York group reported on its sifting and weighing
of the evidence for fluoride?
In a nutshell, the
group said it could not come to any definite
conclusion about any of the points because the
evidence was so poor. As Sheldon commented later:
"We were surprised that, in spite of the large
number of studies carried out over several decades,
there is a dearth of reliable evidence with which to
inform policy."
On the question of
effectiveness, the report says: "To have clear
confidence in the ability to answer the question,
the quality of the evidence would have to be
higher." And on safety: "Some possible adverse
effects may take many years to develop . . . and so
the relationship may go un- detected." Does it
reduce social inequalities? "The evidence is of
insufficient quality to allow confident statements
about whether there is an impact on social
inequalities."
The one positive
conclusion was that more high-quality research was
needed to discover the truth.
But anyone reading
the press releases issued by the BMA, the BDA and
others could be forgiven for not appreciating that
message. "The review confirms that water
fluoridation is safe and effective," trumpeted the
BDA's release, which went on to declare: "The report
confirms that fluoridation reduces dental health
inequalities." The BMA was equally gung-ho: "There
is no evidence of any adverse risk to human health.
Fluoridation is the most effective way to reduce
dental health inequalities".
It's easy to see
why the review committee members are so aggrieved.
The BDA and the BMA had taken their case to an
appeal court of their peers, but when it was thrown
out for lack of evidence they responded by issuing
press releases claiming victory. Calls to both
bodies found them unrepentant. "We believe we gave
an accurate summary," said the British Fluoridation
Society, whose release echoed those of the other two
organisations. "We believe the report does support
fluoridation. Lord Baldwin has taken our statements
out of context."
Ian Wylie, chief
executive of the BDA, said fluoridation was one of
the best measures for dental health and he wanted to
see it go ahead, although he was keen for more
research.
It is tempting to
giggle at the sight of a trouserless hell-fire
preacher explaining how he was wrestling with sin,
but there are serious issues here of trust. The
public is already sceptical of reassurances on
health matters from official bodies. In the long
term, such spinning on the contents of an
inconvenient review will do nothing to improve that.
|
