Short term reactions to acupuncture a cross-sectional survey of patient reports

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1 Short term reactions to acupuncture a cross-sectional survey of patient reports Hugh MacPherson, Kate Thomas Hugh MacPherson senior research fellow Department of Health Sciences University of York Kate Thomas professor School of Healthcare University of Leeds Correspondence: Hugh MacPherson hm18@york.ac.uk Abstract Objective To explore the type and frequency of short term reactions associated with a single acupuncture treatment. Methods As part of recruitment to a large-scale prospective survey of the safety of acupuncture, 9408 consecutive patients each completed one survey form soon after receiving treatment with acupuncture, and returned it directly to the research centre. On this form, patients were asked to report on a range of possible short term reactions relating to their most recent acupuncture treatment using a checklist of options. Results At least one short term reaction to acupuncture during or immediately after treatment was reported by 94.6% (CI 94.2 to 95.1) of patients, an average of 1.8 reactions per patient. The most common experiences reported were feeling relaxed (79.1%) followed by feeling energised (32.7%). A total of 24.4% of patients reported tiredness or drowsiness, with obvious implications for safety if the patient intended to drive after treatment. Negative reactions, such as pain and bruising at the site of needling, were reported by 29.7% of patients who were more likely to be female patients (OR 1.58), patients under the age of 40 (OR 1.62), patients who had consulted their GP or hospital specialist beforehand (OR 1.30), patients consulting their acupuncturist for the first time (OR 1.24), and patients treated by an acupuncturist with less than two years experience since qualification (OR 1.24). Only 13 patients were unwilling to have acupuncture again as a result of these short term reactions. Conclusion In this large cross-sectional study, extensive patient reports showed that positive reactions to acupuncture treatment were very common. Tiredness, drowsiness and a range of negative reactions were also frequently reported. Almost all patients were willing to experience these reactions again. Introduction Recent research into the safety of acupuncture has usually been conducted via large-scale surveys where the type and frequency of adverse events associated with acupuncture have been recorded. Studies have either been retrospective or prospective, the latter providing more robust data, and have involved either acupuncturists in monitoring the effects of their treatments on patients, or patients in reporting their experience of adverse events. While these safety studies have necessarily focused on adverse events, questions have been raised as to whether all adverse reactions were necessarily experienced as negative by patients. Previous research has found that some negative short term reactions to treatment were what might be called aggravations, where, although symptoms were aggravated (became worse after treatment), a strong improvement of symptoms followed, so that the patient was much better than prior to the treatment that caused the aggravation. In our recent practitioner survey of adverse events, 2.8% of treatments were reported as causing a worsening of symptoms, but in the majority of cases (2.4%) a subsequent improvement in symptoms was reported. 1 Acupuncturists sometimes describe this type of aggravation as a healing crisis, known in Japan as the Menken phenomenon. 2 Our interest in all short term reactions to treatment, not just aggravations to symptoms, informed our first safety study, 1 which we conducted with members of the British Acupuncture Council. Acupuncturists monitored more than treatments over a one-month period in 2001, and recorded on standardised documentation short term reactions to treatment as reported by their patients. We labelled these as mild and transient, with the most common reports being of feeling 112

2 relaxed (reported in 11.9% of treatments) and feeling energised (6.6%). However we also received reports of tiredness or drowsiness (3.7%), as well as a range of negative reactions (6.8%). In the study we report here, we were interested in collecting data on the frequency and type of short term reactions reported by patients during or immediately after treatment. This study was part of a large safety research project, two parts of which are already reported: the profile and characteristics of the 9408 participants, 3 and the adverse events reported by the same group of patients three months after baseline. 4 In this paper we described patients reports of short term reactions to treatment, presenting the type and frequency of reactions and related data including reports of aggravations, that we hope adds to our understanding of how patients experience acupuncture. Methods In a large-scale national survey, patients were recruited through their acupuncturists, all of whom were UK based members of the British Acupuncture Council currently in practice. All 1955 members were invited to assist with this survey, and 638 (33%) agreed to participate. We collected information on acupuncturists who agreed to participate as well as those who declined, including their sex, years in practice, where they trained and the number of patients they were treating a week. The British Acupuncture Council, a self-regulating professional body for acupuncturists practising in the UK, requires accredited training colleges to provide a minimum of three years full-time training or equivalent. In order to maximise the involvement of practitioners, our survey did not link individual patients to specific practitioners. However, by using colour coded consent forms, we were able to determine the number of years that the patient s practitioner had been in practice, categorised as less than two years, two to five years, five to 10 years, 10 to 15 years and over 15 years experience. Based on number of patients normally seen by the practitioner, we sent each one between 20 and 60 survey forms. We asked them to hand out forms as soon as possible to all consecutive patients who were over 18 years old, who were able to complete the form and who gave consent. Each patient was included once only. A total of forms were distributed to practitioners, but we do not know the precise number of these handed out to patients. After the acupuncture session, participating patients recorded age, sex, whether they were first time acupuncture patients, and their primary reason for consulting, coded using the International Classification of Primary Care. 5 Patients also provided us with information on their pathway to care, whether they were consulting their acupuncturist for the first time, whether they had had acupuncture before and whether the National Health Service was paying for their acupuncture treatment. Patients were asked to report short term reactions, by answering the question: Thinking about the visit at which you were given this form, did you experience during or immediately after your acupuncture any of the following? We provided a checklist of possible short term reactions drawn from the results of two recently published practitioner surveys. 1;6 Patients were then asked, Given this experience, would you be willing to have acupuncture treatment again? Patients then returned the form direct to the research centre using a Freepost envelope, not seen by their acupuncturist. These data provided the primary outcome for the study we report here. Ethical approval for this study was given by the Northern & Yorkshire Multi-centre Research Ethics Committee. The Statistical Package for the Social Sciences (SPSS) was used for data analysis. Confidence intervals for proportions were calculated using Confidence Interval Analysis (CIA). To control for confounding, binary logistic regression was used to estimate relative risk in the form of adjusted odds ratios for those variables that showed a statistically significant association (P<0.05) in the univariate analysis. Results A total of 9408 patients returned a completed questionnaire, an average of 15 per participating practitioner. The patients mean age was 51 years and 74% were female. Other characteristics are presented in Table 1 (these are submitted for publication elsewhere). 3 Of these patients, 8904 (94.6 %) reported experiencing short term reactions associated with their acupuncture. This corresponds to a rate of 94.7 % of patients experiencing at least one reaction (95% CI 94.2 to 95.1) with an average of 1.8 reactions per patient. The breakdown of the type 113

3 Table 1 Characteristics of patients who participated in the survey (total responses = 9408) Number Percentage Sex (n=9403): Male Female Average age, years (n=9315) 51 Reason for consultation most commonly reported:* Musculo-skeletal Psychological General Neurological Gynaecological/obstetric Respiratory General wellbeing** Previously consulted their GP or hospital specialist about their main problem or symptom (n=9337) Receiving acupuncture for the first time (n=9381) Treatment paid for by NHS (n=9337) *Coded and classified according to the International Classification of Primary Care. 5 **Additional category and frequency of these reactions is presented in Table 2. We classified each reaction as: a) positive, likely to be considered a good experience; b) tiredness or drowsiness (which could be interpreted as either positive or negative); and c) negative, likely to be considered an unwanted experience. Positive reactions were most common, especially a feeling of relaxation (79% of patients), followed by feeling energised (33%). In addition 24% of patients reported experiences of tiredness or drowsiness. A range of negative reactions were also reported (30%), most commonly an experience of pain at the site where a needle was inserted. A worsening of their existing condition was reported by 1.8%. Table 3 shows the results of the multivariate analysis for patients who reported positive short term reactions compared with those who did not. Similarly, we present the results for short term tiredness or drowsiness reactions in Table 4 and negative short term reactions in Table 5. From this analysis, patients were more likely to report positive short term reactions if they were male, or had had acupuncture previously, or had consulted their acupuncturist before, or were presenting with a psychological, gynaecological or obstetric condition, or for general wellbeing; but not if they were consulting for a musculoskeletal condition or they had consulted their GP or hospital specialist beforehand. Tiredness or drowsiness was associated more with female patients, patients under the age of 40, or patients who had consulted their GP or hospital specialist beforehand. Negative reactions were more likely to be reported by female patients, patients under the age of 40, patients who had consulted their GP or hospital specialist beforehand, or patients consulting their acupuncturist for the first time. In Table 6, we present the numbers willing and unwilling to have acupuncture treatment again. These data are presented in the same three categories as discussed above: positive reactions, tiredness or drowsiness reactions, and negative reactions. The overall rate of unwillingness was only 0.14 patients per 100 consultations. Surprisingly there was no 114

4 Table 2 Type and frequency of short term reactions associated with acupuncture (n=9408) Type of event Number of Short term reaction rate 95% CI reported reactions per 100 treatments Positive reactions Relaxed , 79.8 Energised , 33.6 Other positive , 2.1 Sub Total Tiredness or drowsiness reactions , 25.3 Negative reactions Pain where needle was inserted , 12.9 Bruising , 4.4 Pain other than at site of needling , 4.4 Faint / dizzy , 3.0 Worsening of condition , 2.0 Nauseous , 1.4 Sweating , 1.0 Bleeding , 0.9 Disorientation / anxiety / nervousness / insomnia / emotional , 0.9 Ache/discomfort other than at needle point , 0.7 Other negative , 0.5 Itching / pins & needles / tingling / burning sensation , 0.5 Irritation / ache at needle point , 0.4 Sub Total , 30.4 Total significant difference between the three categories, providing evidence that negative short term reactions did not affect people s willingness to have acupuncture again. In Table 7 we use a binary logistic regression model and find that only two factors were significantly (P<0.05) associated with an unwillingness to have acupuncture again: having had acupuncture recommended by an NHS practitioner (such as a GP, nurse, or physiotherapist) and having acupuncture for the first time. Discussion Our main result was that 94.6% (CI 94.2 to 95.1) of patients reported experiencing at least one short term reaction to acupuncture during or immediately after treatment, with an average of 1.8 reactions per patient. This was an unexpectedly high proportion, with the most common experiences being reported as feeling relaxed (79.1%) followed by feeling energised (32.7%). A total of 24.4% of patients reported feeling tired or drowsy. Negative reactions, such as pain and bruising at the site of needling, were reported by 29.7% of patients; however, aggravation of symptoms was only reported by 1.8% of patients. Our post hoc classification of adverse events into three major categories has been useful in some ways, but also has limitations. With regard to the positive category for example, it may not always be positive to be energised or relaxed. Similarly, some people might experience being energised or relaxed as negative. We had difficulty in categorising tiredness or drowsiness as either positive or negative and therefore created a separate category. If one takes the view that patient safety is the key issue, then clearly excessive tiredness or drowsiness must be seen as a risk factor. In addition individual reporting 115

5 Table 3 Adjusted odds ratios for positive short term reactions* (n=9408) Response variable Proportions experiencing Adjusted relative risk:** a positive reaction* Female patients 6228/6957 (90%) Male patients 2247/2442 (92%) Patients who were having acupuncture for the first time 1046/1253 (83%) Patients who had had acupuncture previously 7417/8128 (91%) Patients who were consulting their current acupuncturist for the first time 1014/1204 (84%) Patients who had consulted their current acupuncturist before 7360/8085 (91%) Patients who had not consulted for a psychological condition 7446/8290 (90%) Patients who had consulted for a psychological condition 977/1047 (93%) Patients who had not consulted for a gynaecological or obstetric condition 7971/8856 (90%) Patients who had consulted for a gynaecological or obstetric condition 452/ 481 (94%) Patients who had consulted for a musculoskeletal condition 3133/3558 (88%) Patients who had not consulted for musculoskeletal condition 5290/5779 (92%) Patients who had not consulted for general wellbeing 8055/8958 (90%) Patients who had consulted for general wellbeing 424/ 446 (95%) Patients who had consulted their GP or specialist about their condition 6496/7257 (90%) Patients who had not consulted their GP or specialist about their condition 1920/2080 (92%) Odds Ratio (95% CI) 1.45 (1.22, 1.72) 1.62 (1.32, 2.00) 1.41 (1.14, 1.75) P= (1.13, 1.95) P= (1.15, 2.53) P= (1.07, 1.44) P= (1.02, 2.51) P= (1.06, 1.53) P=0.011 * Positive reactions are listed in Table 2. ** All variables in the left hand column were used in the logistic regression model and were shown to have an independent effect on the likelihood of patients reporting short term reactions. No associations were found for the other known variables. Table 4 Adjusted odds ratios for short term reactions of tiredness or drowsiness (n=9408) Response variable Proportions experiencing Adjusted relative risk:* tiredness or drowsiness Odds Ratio (95% CI) Male patients 436/2442 (18%) 1.65 (1.46, 1.85) Female patients 1859/6957 (27%) Patients aged 40 years and over 1528/6942 (22%) Patients age under 40 years 739/2369 (31%) 1.58 (1.43, 1.76) Patients who had not consulted their GP or specialist about their condition 445/2080 (21%) 1.23 (1.10, 1.39) Patients who had consulted their GP or specialist about their condition 1837/7257 (25%) P=0.001 *All variables in the left hand column were used in the logistic regression model and were shown to have an independent effect on the likelihood of patients reporting short term reactions. No associations were found for the other known variables

6 Table 5 Adjusted odds ratios for negative short term reactions*(n=9408) Response variable Proportions experiencing Adjusted relative risk:** a negative reaction* Odds Ratio (95% CI) Patients who had acupuncturists who had been in practice more than two years 3462/8787 (39%) 1.24 (1.05, 1.47) Patients who had acupuncturists who had been in practice less than two years 282/ 616 (46%) P=0.013 Male patients 779/2442 (32%) Female patients 2964/6957 (43%) Patients aged 40 years and over 2544/6942 (37%) Patients aged under 40 years 1160/2369 (49%) Patients who had not consulted their GP or specialist about their condition 733/2080 (35%) Patients who had consulted their GP or specialist about their condition 2990/7257 (41%) Table 6 Patients willingness to have acupuncture treatment again Reported experience of short term reactions Number willing Number unwilling Those unwilling to 95% CI to have to have have acupuncture acupuncture again acupuncture again again - rate per 100 treatments Positive short term reactions (n = 8428) , Tiredness or drowsiness short term reactions (n=2284) , Negative short term reactions (n =3726) , All cases (n = 9346) , will vary, and one person s relaxation may be another s tiredness, and this variation may be influenced by many factors such as culture, expectations, and the disease being treated. Another caveat concerning the data presented here is that the large sample size inevitably led to associations that are statistically significant but not necessarily clinically meaningful. The potential clinical relevance of these associations therefore needs to be considered and interpreted in each case, as the differences observed may be small in absolute terms. In our two previous publications we discussed the practitioners and patients responding to this survey, 3;4 concluding that the sample obtained is reasonably representative of the population it aims to describe with respect to known characteristics. However, when patients provide reports of their experiences in a questionnaire, it is possible that some biases will intrude. For example, for some patients there might be a tendency to under-report the negative reactions in order to protect their acupuncturist or acupuncture generally, due perhaps to a loyalty to their chosen approach to health care. With other patients there might be a counter tendency to over-report, because the user-friendly checklist we provided in the questionnaire encouraged the 1.58 (1.43, 1.92) 1.62 (1.47, 1.78) 1.30 (1.17, 1.44) Patients who had consulted current acupuncturist before 3167/8085 (39%) 1.24 (1.09, 1.41) Patients who had consulted current acupuncturist for first time 539/1204 (45%) P=0.001 * Negative reactions are listed in Table 2. ** All variables in the left hand column were used in the logistic regression model and were shown to have an independent effect on the likelihood of patients reporting short term reactions. No associations were found for the other known variables

7 Table 7 Adjusted odds ratios for patients unwillingness to have acupuncture treatment again (n=9346) Proportions unwilling to have acupuncture again Patients who did not have acupuncture recommended by an NHS practitioner (GP, nurse, physiotherapist, etc) 8/8129 (0.10%) Patients who had acupuncture recommended by an 4/ 913 (0.44%) NHS practitioner ticking of boxes. We cannot know whether patients of non-participating practitioners, or non-participating patients of participating practitioners, would have provided the study with different data. It is possible to compare our patient reports of short term reactions with practitioner reports of their patients short term reactions from the previous survey conducted in While the practitioners in both studies were drawn from the same professional association, the British Acupuncture Council, the patient populations are different. Patients report short term reactions approximately five times more frequently than practitioners. For negative reactions related to pain, the difference is nearer tenfold. This raises the question as to whether practitioners are unaware of the pain they cause, or whether the dull ache usually experienced when de qi is obtained at an acupuncture point, which most acupuncturists in the British Acupuncture Council regard as a requirement for a treatment, is reported by some patients as pain. The difference overall might be related to the known tendency among healthcare practitioners to underreport adverse events. 8;9 Nevertheless, it is worth noting that in both our surveys, the most common three types of reactions reported were the same, and in the same order of frequency, namely feeling relaxed, feeling energised and feeling tired or drowsy. We have also compared our results with other surveys, and found variations on a number of counts. For example, the estimates of tiredness after treatment have been wide-ranging: as high as 41%, 10 but more Adjusted relative risk*: Odds Ratio (95% CI) 3.77 (1.12, 12.66) P=0.032 Patients having had acupuncture before 7/8089 (0.09%) 5.95 (1.90, 18.61) P=0.002 Patients having acupuncture for the first time 6/1240 (0.48%) * All variables in the left hand column were used in the logistic regression model and were shown to have an independent effect on the likelihood of patients reporting short term reactions. No associations were found for the other known variables. commonly around 3%, 11 compared to 24% in this survey. Our evidence does not support a report in the literature that tiredness or drowsiness occurs more commonly after a patient s first session of acupuncture. 11 In terms of safety, however, tiredness and drowsiness seems likely to be the most worrying potential risk, as it could compromise a patient s ability to drive home safely after acupuncture. 12 One of our lines of enquiry in this study was to explore the frequency that patients reported a worsening of their symptoms as a result of acupuncture. Immediately following a single session of acupuncture, only 1.8% of our patients reported an aggravation to their condition, lower than clinical anecdotes had led us to expect. This result lies between the 2.8% reported in two other surveys, 1;11 and the 1% in another. 6 Our data suggest that the risk of negative short term reactions, particularly reported pain at the site of needling, is associated with patient characteristics, practitioner characteristics and consulting behaviour, including being new to acupuncture. We found no association between reported negative reactions and particular reasons for consulting, suggesting that pain at the site of needling is not linked to the presentation of painful conditions per se. In contrast, reports of positive reactions were associated with returning acupuncture patients, and with nonmusculoskeletal reasons for consulting (including psychological conditions and general wellbeing). These results are not incompatible with studies that 118

8 have shown patient reports of relaxation following acupuncture for musculoskeletal conditions such as low back pain. 13 What we have shown is that patients with these conditions are significantly less likely to report a relaxation response, compared to patients with other conditions. It is possible that short term reactions play an important role in providing some evidence for patients that acupuncture is actually doing something, providing patients with a strong motivation to continue with acupuncture long enough to be effective. Previous research has indicated that it takes on average the first six or so treatments before substantial benefits of treatment are experienced. 14;15 Is it possible then that without these short term reactions, many more patients might have believed that acupuncture was ineffective, and therefore not continued with it for a sufficient number of sessions? One can also speculate that these ubiquitous and generally positive short term reactions have played a crucial role in extending acupuncture s impact in the West in recent years, in some way compensating for the low level of gold standard evidence to support acupuncture s reputation for effectiveness. A number of interesting questions for further research are raised by this study. Firstly, it is interesting to speculate what physiological responses might explain such marked positive short term reactions. Acupuncture needles produce a range of biophysical reactions. While our knowledge of these processes is limited, we do know that acupuncture releases endogenous opioid peptides that can generate relaxed happy feelings, as well as oxytocin, a possible mediator of anti-stress effects, and serotonin, where a deficiency is linked to depression These effects have been demonstrated to last up to 12 hours, and have similarities with the physiological processes that result from vigorous physical exercise. 19 However acupuncture also appears to set off longer term neurophysiological processes, and it has been suggested that these are fundamentally different from short term ones, 20;21 and may be responsible for longer term outcomes reported in the literature. 13;22;23 Secondly, further research is indicated to explore patients and practitioners experiences. Lines of enquiry include patients perceptions of pain from needling, and the more general question of how patients value both positive and negative reactions. Given that drowsiness and tiredness are likely to be the most serious of the common risk factors, further data could be collected to give a more accurate picture of the real risk, for example by reporting on the extent that they felt compromised in their ability to drive, use machinery, cook or walk. Research could also usefully explore why so few patients were unwilling to have acupuncture again after experiencing short term reactions. From our data, only 13 patients were unwilling to have acupuncture again because of their experience of these short term reactions, a rate of 0.14% of treatments (95% CI 0.08 to 0.24). Given that not all reactions to treatment were positive, this is an exceptionally low rate, and surprisingly not related to whether the reaction was positive or negative. A qualitative study could explore in depth the reasons patients have for being willing to continue with acupuncture, hopefully helping to explain why new patients and patients who had been recommended by an NHS practitioner are less willing to continue. Finally, we could investigate the impact short term reactions may have on practitioners, how they integrate this knowledge into their treatments for example to modify their choice of points, thereby tailoring treatment more closely to the needs of the patient. Conclusion In a large-scale prospective patient survey, we found that 95% of patients reported reactions to acupuncture during or immediately after a single session, an unexpectedly high level. The most common reactions were positive, namely feeling relaxed and feeling energised, followed by feelings of tiredness or drowsiness. Despite patients also feeling a range of negative reactions, including pain at the site of needling, almost all patients were willing to have acupuncture again. Acknowledgements We acknowledge the assistance of the British Acupuncture Council who funded the study, the patients and practitioners who participated, Tony Scullion who managed much of the data collection, Bin Liu who helped with the analysis, and Richard Blackwell and Jennifer Dale who contributed to the interpretation of the results

9 Reference list 1. MacPherson H, Thomas K, Walters S, Fitter M. A prospective survey of adverse events and treatment reactions following 34,000 consultations with professional acupuncturists. Acupunct Med 2001;19(2): Yamashita H, Tsukayama H, Tanno Y, Nishijo K. Adverse events in acupuncture and moxibustion treatment: a sixyear survey at a national clinic in Japan. J Altern Complement Med 1999;5(3): MacPherson H, Sinclair-Lian N, and Thomas K. Patients seeking care from acupuncture practitioners in the UK: a national survey. Submitted for publication Macpherson H, Scullion A, Thomas KJ, Walters S. Patient reports of adverse events associated with acupuncture treatment: a prospective national survey. Qual Saf Health Care 2004;13(5): Lamberts H, Wood M. International Classification of Primary Care. Oxford University Press, White A, Hayhoe S, Hart A, Ernst E. BMAS and AACP British Medical Acupuncture Society and Acupuncture Association of Chartered Physiotherapists. Survey of adverse events following acupuncture (SAFA): a prospective study of 32,000 consultations. Acupunct Med 2001;19(2): Gould A, MacPherson H. Patient perspectives on outcomes after treatment with acupuncture. J Altern Complement Med 2001;7(3): Moride Y, Haramburu F, Requejo AA, Begaud B. Underreporting of adverse drug reactions in general practice. Br J Clin Pharmacol 1997;43(2): Smith CC, Bennett PM, Pearce HM, Harrison PI, Reynolds DJ, Aronson JK et al. Adverse drug reactions in a hospital general medical unit meriting notification to the Committee on Safety of Medicines. Br J Clin Pharmacol 1996;42(4): List T, Helkimo M. Adverse events of acupuncture and occlusal splint therapy in the treatment of craniomandibular disorders. Cranio 1992;10(4): Yamashita H, Tsukayama H, Hori N, Kimura T, Tanno Y. Incidence of adverse reactions associated with acupuncture. J Altern Complement Med 2000;6(4): Brattberg G. Acupuncture treatments: a traffic hazard? Am J Acupunct 1986;14: Thomas KJ, MacPherson H, Thorpe L, Ratcliffe J, Brazier J, Campbell M et al. Longer term clinical and economic benefits of offering acupuncture to patients with persistent low back pain. Final report submitted to NCCHTA MacPherson H, Fitter M. Factors that influence outcome: an evaluation of change with acupuncture. Acupunct Med 1998;16(1): Ezzo J, Berman B, Hadhazy VA, Jadad AR, Lao L, Singh BB. Is acupuncture effective for the treatment of chronic pain? A systematic review. Pain 2000;86(3): Andersson S, Lundeberg T. Acupuncture from empiricism to science: functional background to acupuncture effects in pain and disease. Med Hypotheses 1995;45(3): Review. 17. Pomeranz B. Scientific research into acupuncture for the relief of pain. J Altern Complement Med 1996;2(1): Hsu DT. Acupuncture. A review. Reg Anesth 1996;21(4): Andersson S, Lundeberg T. Acupuncture from empiricism to science: functional background to acupuncture effects in pain and disease. Med Hypotheses 1995;45(3): Carlsson C. Acupuncture mechanisms for clinically relevant long term effects reconsideration and a hypothesis. Acupunct Med 2002;20(2-3): Bensoussan A. The Vital Meridian: Modern Exploration of Acupuncture. Churchill Livingstone, Kjendahl A, Sallstrom S, Osten PE, Stanghelle JK, Borchgrevink CF. A one year follow-up study on the effects of acupuncture in the treatment of stroke patients in the subacute stage: a randomized, controlled study. Clin Rehabil 1997;11(3): Vincent CA. A controlled trial of the treatment of migraine by acupuncture. Clin J Pain 1989;5(4): Acupunct Med: first published as /aim on 1 January Downloaded from on 20 August 2018 by guest. Protected by copyright