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

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

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 events—two patients had needles left in, and one patient had moxibustion burns to the skin—were 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 reported—mild 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

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.

Table.

Details of 43 minor adverse events associated with 34 407 acupuncture treatments, all reported as “significant” by practitioners

Minor adverse events	No of occurrences	Descriptions
Severe nausea, actual fainting, severe dizziness, heavy sweating, and vomiting	12	5 cases of severe nausea (2 with feeling faint, sweating, and dizziness; 1 started next day and lasted several days; 1 started 4 days later with angina and nose bleeds); 4 fainted (2 with nausea and dizziness); 1 severe dizziness and feeling faint; 1 heavy sweating and slight needle shock; 1 vomiting after treatment
Unexpected, severe, and prolonged aggravation of existing symptoms	7	1 difficulty walking the next day because of stiff, painful legs; 1 increase in shoulder pain for 20 minutes; 1 neck and shoulder pain increase for 1 week; 1 morning sickness worsened; 1 diarrhoea in patient with colitis; 1 constipation in patient with irritable bowel; 1 temporary aggravation of neck pain
Prolonged and unacceptable pain and bruising	5	3 local pain at site of needling; 2 heavy bruising
Psychological and emotional reactions	4	1 emotional outburst and anger at practitioner; 1 feeling of panic with sensation of heat and sweatiness; 1 intense emotional release, feeling manic, relaxed, rage, and confusion; 1 depression with anxiety
Avoidable errors	3	2 forgotten needles; 1 moxibustion burns at 2 points
Miscellaneous symptoms	10	1 haematuria next day; 1 headache next day; 1 unwell, tired, sore throat, breathless, and achy; 1 knee went weak and patient could not stand on it; 1 very tired next day; 1 felt sick and exhausted; 1 severe drowsiness; 1 tiredness next day with 10 hours of diarrhoea; 1 rash after taking herbs; 1 rash developed on abdomen a few days after treatment
Unspecified	2