Papers

The York acupuncture safety study: prospective survey of 34 000 treatments by traditional acupuncturists

Hugh MacPherson, research director ^a, Kate Thomas, deputy director ^b, Stephen Walters, lecturer in medical statistics ^c, Mike Fitter, research consultant ^a. 

^a See Editorial by Vincent and p 485 Foundation for Traditional Chinese Medicine, York YO24 4EY, ^b Medical Care Research Unit, University of Sheffield, Sheffield S1 4DA, ^c Sheffield Health Economics Group, School of Health and Related Research, University of Sheffield

Correspondence to: H MacPherson hugh{at}ftcm.org.uk

Recent reports have highlighted the importance of having good evidence on the safety of acupuncture. ^{1 2} Sound evidence on the risks associated with acupuncture is, however, scarce.³ Our primary aim, therefore, was to describe the type and frequency of adverse events after acupuncture. A secondary aim was to examine mild transient reactions associated with acupuncture, some of which may indicate a positive response to treatment.

	Participants, methods, and results

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The study involved a prospective postal audit of treatments undertaken during a four week period in 2000. All 1848 professional acupuncturists who were members of the British Acupuncture Council and were practising in the United Kingdom were invited to record details of adverse events and mild transient reactions after treatment. Standardised self report forms were used. Participating practitioners also provided information on themselves, including age, sex, length of training, and years of practice. To have a 95% probability that no serious event occurs in n treatments, a survey sample size needs to be three times n.⁴ On this basis, a sample of 30 000 treatments was sought. Piloting indicated that a four week period was needed.

A total of 574 practitioners participated, 31% of the total population. The mean age of participants was 44.8 years (range 23-79 years), 65% were female, and 62% had been practising acupuncture for more than five years. Information on sex, training college, and length of practice was available from the British Acupuncture Council's database. Participants were sufficiently representative of the population of practitioners for a re-weighting of the primary data to be unnecessary. Participating practitioners reported on 34 407 treatments.

Practitioners were asked to give details of any adverse events they considered to be "significant," including any event that was "unusual, novel, dangerous, significantly inconvenient, or requiring further information." There were no reports of serious adverse events, defined as events requiring hospital admission, leading to permanent disability, or resulting in death (95% confidence interval 0 to 1.1 per 10 000 treatments). Practitioners did, however, report 43 minor adverse events, a rate of 1.3 (0.9 to 1.7) per 1000 treatments. The most common events were severe nausea and fainting (table). Three avoidable eventstwo patients had needles left in, and one patient had moxibustion burns to the skinwere caused by practitioners' errors.

Participating practitioners recorded 10 920 mild transient reactions occurring in 5136 treatments, 15% (14.6% to 15.3%) of the 34 407 total. Some local reactions at the site of needling were reportedmild bruising in 587 (1.7%) cases, pain in 422 (1.2%) cases, and bleeding in 126 (0.4%) cases. Patients experienced an aggravation of existing symptoms after 966 (2.8%) treatments, 830 (86%) of which were followed by an improvement, possibly indicating a positive "healing crisis." The most commonly reported mild transient reactions were "feeling relaxed" in 4098 (11.9%) cases and "feeling energised" in 2267 (6.6%) cases, symptoms that often indicate an encouraging response to treatment.³

	Comment

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In this prospective survey, no serious adverse events were reported after 34 407 acupuncture treatments. This is consistent, with 95% confidence, with an underlying serious adverse event rate of between 0 and 1.1 per 10 000 treatments. This conclusion was based on data collected over a four week period by one in three of the members of the British Acupuncture Council. Even given the potential bias of self reporting, this is important evidence on public health and safety as professional acupuncturists deliver approximately two million treatments per year in the United Kingdom. Comparison of this adverse event rate for acupuncture with those of drugs routinely prescribed in primary care suggests that acupuncture is a relatively safe form of treatment.⁵ Further research measuring patients' experience of adverse events is merited.

	Acknowledgments

Contributors: HMacP initiated the project, coordinated the study, and is the guarantor. KT and MF contributed to the study design, interpretation of results, and drafting of the manuscript. SW analysed the data and assisted with the interpretation of results. The study was adapted from a survey design developed by Adrian White and colleagues. Alan Bensoussan, Stephen Birch, Alan Breen, Roy Carr-Hill, and Adrian White provided valuable comments on a draft protocol.

	Footnotes

Funding: The study was supported by a grant from the British Acupuncture Council.

Competing interests: None declared.

	References

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1.	British Medical Association Board of Science and Education. Acupuncture: efficacy, safety and practice. London: Harwood Academic Publishers, 2000.
2.	House of Lords. Complementary and alternative medicine. London: Stationery Office, 2000. (Report of the Select Committee on Science and Technology.)
3.	MacPherson H. How safe is acupuncture? Developing the evidence on risk. J Alternative Complementary Med 1999; 5: 223-224[Medline].
4.	Eypasch E, Lefering R, Kum CK, Toidl H. Probability of adverse events that have not yet occurred: a statistical reminder. BMJ 1995; 311: 619-620[Free Full Text].
5.	Tranmer MR, Moore RA, Reynolds DJM, McQuay HJ. Quantitative estimation of rare adverse events, which follow a biological progression: a new model applied to chronic NSAID use. Pain 2000; 85: 169-182[CrossRef][Medline].

(Accepted 23 May 2001)