Is
complementary/alternative medicine safe?
Complementary/alternative medicine (CAM) is
popular but is it safe? Following last month's article, Professor Edzard Ernst
and Dr Adriane Fugh-Berman assess the evidence on acupuncture, homeopathy, and
chiropractic
Many users and practitioners of CAM assert that CAM is entirely safe.
Therapies are perceived to be natural and thus, in a stunning leap of logic,
non-toxic. Most therapies have both direct risks1-5 and indirect
risks. Although the incidence of severe adverse effects following acupuncture,
homeopathy, and chiropractic is probably low, complications do occur and are
being reported in the medical literature. The actual incidence of such
complications is unknown. Due to the lack of reliable reporting systems for
adverse events, we have no choice but to rely on largely anecdotal data.
Acupuncture
A survey of 1135 Norwegian doctors and 197 acupuncturists found that
12 per cent of doctors and 31 per cent of acupuncturists reported adverse
effects. The most common adverse reactions were fainting, local skin infections,
and increased pain6. Internal injuries have been reported, including
pneumothorax, cardiac tamponade, and spinal cord lesions; a Medline search for
adverse effects of acupuncture between 1981 and 1994 uncovered 78 reports with a
total of 193 patients7. Pneumothorax, in 23 patients, was the most
common internal injury. The most common complication overall was hepatitis in
100 patients. In Rhode Island in 1984 a single acupuncturist was responsible for
an outbreak of 35 cases of hepatitis8. Infection from inadequately sterilised
reusable needles is clearly a completely preventable problem; today only
disposable needles are currently used in the US. A recent systematic review of
all published reports of severe adverse effects concluded9 that
'serious adverse events have been associated with acupuncture. Acupuncturists
should demonstrate how successfully they minimize the risks and put in place
regulatory and surveillance systems that enable us to define the extent of the
problem more closely. If this should prove to be unsuccessful, an
intra-professional problem for the acupuncturists could become a general, social
one.'
Homeopathy
There are few reports of direct harm from
homeopathy, but there is one reported case of pancreatitis following ingestion
of a homeopathic remedy10. 'Low potency' (less dilute) homeopathic preparations
can contain enough allergen to cause a reaction in atopic individuals or enough
heavy metal to be potentially toxic11.
Chiropractic
Although infrequent, complications from
chiropractic can be severe. The incidence of vascular accidents is estimated to
be one to four per million treatments; 359 vascular accidents were registered to
the Stroke Council of the American Heart Association as of 198112. A
survey of 177 neurologists in California reported 55 strokes associated with
spinal manipulation in a two year period13. An authoritative, recent
review of all published reports of complications related to spinal manipulation
found 298 such incidents: 165 vertebrobasilar accidents, 61 cases with disc
herniation or progression to cauda equina syndrome, 13 cerebral complications
other than the above-mentioned and 56 other types of complications14.
The authors draw far-reaching conclusions: 'referral for spinal manipulation
therapy should not be made to practitioners applying rotary cervical
manipulation'.
Only two prospective investigations on the safety of chiropractic
exist15,16. With a total sample of 1500 patients, they show that
about half of all patients seeing a chiropractor will experience adverse
effects. These are usually mild and transientÑlocal pain was the most
frequent adverse effect and there was no serious complication in this series.
Other risks
In addition to direct hazards, there are indirect risks associated
with CAM. These include misdiagnosis of treatable conditions; the use of
therapies without proven efficacy, when therapies with proven efficacy are
available; and disregard of contraindications or interactions. Examples of such
indirect risks are the negative attitude of some practitioners against
immunisation17 or the overt over-use of chiropractors of X-rays18.
These indirect risks are complex, delicate issues that will be an important
component of future debates on establishing competence for and regulating CAM
practitioners.
Risk evaluation
In conventional medicine, a 'mini
risk/benefit evaluation' is done whenever a treatment is prescribed or
administered. Substantial risks are acceptable when the expected benefits are
high (as in cancer treatment), while, in cases where the condition is minor or
the benefit questionable (for instance the common cold), only trivial risks are
acceptable. It must be kept in mind that any benefits of CAM cannot be evaluated
in isolation; rigorous investigation of safety issues must also be undertaken in
order to establish usefulness. Risk/benefit evaluations cannot be done when
only one side of the ratio is known.
Economics
Economic evaluations of CAM are in their
infancy. Assessments of cost-effectiveness must take into account short-term and
long-term direct and indirect costs. An inexpensive therapy with a high rate of
expensive complications is no bargain. On the other hand, an expensive curative
therapy may save long-term costs over an inexpensive treatment used
indefinitely. And, of course, a prerequisite for ascertaining cost-effectiveness
is determining therapeutic effectiveness, and hard data is scanty in the CAM
area19.
The largest amount of evidence for
cost-effectiveness exists for chiropractic as used for low back pain, but no
firm conclusions are as yet possible: a recent trial from the UK suggests that
it might save expense20 while another study from the US implies that
it is not good value for money21. As proper assessments of the cost
questions emerge21-24, serious doubts are raised about the
likelihood that CAM will eventually save money. The more likely scenario is that
it will increase the overall expenditure in our health care systems 22,23.
Because rationing of health care has become a regrettable necessity in
many countries, it is imperative to use proper scientific methods to investigate
the total cost of CAM. Within the financial constraints of the health care
system, a given patient should be treated not only with a therapy that has been
proven to be effective and safe but with one that can be shown to be more
cost-effective than competing options25.
Conclusions
Akin to the conclusion made in last month's article
about the efficacy of CAM, the evidence for or against CAM in terms of safety
and costs is also insufficient, and thus considering rigorous research in this
area is urgently needed.
Edzard Ernst is Professor of Complementary
Medicine and Director of the Department of Complementary Medicine, Postgraduate
Medical School, University of Exeter (e-mail: E.Ernst@exeter.ac.uk); Adriane
Fugh-Berman is a researcher at the National Women's Health Network, Washington
DC, USA (e-mail: fughbera@exchange.nih.gov)
References
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2 Ernst E. Cervical
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3 Ernst E. The safety of homeopathy. Br Homoeop J 1995; 84: 193-4
4
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6
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10 Kerr HD, Yarborough GW. Pancreatitis following ingestion of a
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