Yes, we discussed this study on a previous blog post. But, as it is ‘ACUPUNCTURE AWARENESS WEEK’ in the UK, and because of another reason (which will become clear in a minute) I decided to revisit the trial.
In case you have forgotten, here is its abstract once again:
Background: Hot flashes (HFs) affect up to 75% of menopausal women and pose a considerable health and financial burden. Evidence of acupuncture efficacy as an HF treatment is conflicting.
Objective: To assess the efficacy of Chinese medicine acupuncture against sham acupuncture for menopausal HFs.
Design: Stratified, blind (participants, outcome assessors, and investigators, but not treating acupuncturists), parallel, randomized, sham-controlled trial with equal allocation. (Australia New Zealand Clinical Trials Registry: ACTRN12611000393954)
Setting: Community in Australia.
Participants: Women older than 40 years in the late menopausal transition or postmenopause with at least 7 moderate HFs daily, meeting criteria for Chinese medicine diagnosis of kidney yin deficiency.
Interventions: 10 treatments over 8 weeks of either standardized Chinese medicine needle acupuncture designed to treat kidney yin deficiency or noninsertive sham acupuncture.
Measurements: The primary outcome was HF score at the end of treatment. Secondary outcomes included quality of life, anxiety, depression, and adverse events. Participants were assessed at 4 weeks, the end of treatment, and then 3 and 6 months after the end of treatment. Intention-to-treat analysis was conducted with linear mixed-effects models.
Results: 327 women were randomly assigned to acupuncture (n = 163) or sham acupuncture (n = 164). At the end of treatment, 16% of participants in the acupuncture group and 13% in the sham group were lost to follow-up. Mean HF scores at the end of treatment were 15.36 in the acupuncture group and 15.04 in the sham group (mean difference, 0.33 [95% CI, −1.87 to 2.52]; P = 0.77). No serious adverse events were reported.
Limitation: Participants were predominantly Caucasian and did not have breast cancer or surgical menopause.
Conclusion: Chinese medicine acupuncture was not superior to noninsertive sham acupuncture for women with moderately severe menopausal HFs.
When I first discussed this trial, I commented that the trial has several strengths: it includes a large sample size and the patients were adequately blinded to eliminate the effects of expectations. It was published in a top journal, and we can therefore assume that it was properly peer-reviewed. Combined with the evidence from our previous systematic review, this indicates that acupuncture has no effect beyond placebo.
The reason for bringing it up again is that a comment about the study has recently appeared, not just any old comment but one from the British Medical Acupuncture Society. It is, in my view, gratifying and interesting. It was published on ‘facebook’ and is therefore in danger of getting forgotten. I hope to preserve it by citing it in full.
Here it is:
A large rigorous trial published in a prestigious general medical journal, and the usual mantra rings out – acupuncture is no better than sham. In this case there was not a fraction of difference from a non-penetrating sham in a two-armed trial with over 300 women. Ok,…so we have known for some time that we really need 400 in each arm to demonstrate the usual difference over sham seen in meta-analysis in pain conditions, but there really was not even a sniff of a difference here. So is that it for acupuncture in hot flushes? Well, we have a 40% symptom reduction in both groups, and a strong conviction from some practitioners that it really seems to work. Is 40% enough for a strong conviction? I have heard some dramatic stories from medical acupuncturist colleagues that really would be hard to dismiss as non-specific effects, and from others I have heard relative ambivalence about the effects in hot flushes.
Personally I always try to consider mechanisms, and I wish researchers in the field would do the same before embarking on their trials. That is not intended as a criticism of this trial, but some consideration of mechanisms might allow us to explain all our data, including the contribution of this trial.
Acupuncture has recognised effects that are local to the needle, in the spinal cord (mainly in the segments stimulated) and in the brain (as well as humoral effects in CSF and blood). The latter are probably the mildest of the three categories, and require the best group of patient responders for them to be observable in clinical practice.
Menopausal hot flushes are explained by the effects of reduced oestrogens on the thermoregulatory centre in the anterior hypothalamus. It is certainly plausible that the neuro-inhibitory effects of endogenous opioids such as beta-endorphin, which we know can be released by acupuncture stimulation in experimental settings, could stablise neurones in the anterior hypothalamus that have become irritable due to a sudden drop in oestrogens.
So are endogenous opioids always released by acupuncture? Well, they and their effects seem to be measurable in experiments that use what I call proper acupuncture. That is, strong stimulation to deep somatic tissue. In the laboratory, and indeed in my clinic, this is only usually achieved in a palatable manner by electroacupuncture to muscle, although repeated manual stimulation every few minutes may have similar effects.
Ee et al used a relatively gentle acupuncture protocol, so they may have only generated measurable effects, based on mechanistic speculation, in the most responsive patients, perhaps less than 10%.
What does all this tell us? Well this trial clearly demonstrates that gentle acupuncture protocols generate effects in women with hot flushes via context rather than penetrating needling. In conditions that rely on central effects, I think we still need to consider stronger stimulation protocols and enriched enrollment in trials, ie preselecting responders before randomisation.
In my original comment I also predicted: “One does not need to be a clairvoyant to predict that acupuncturists will now find what they perceive as a flaw in the new study and claim that its results were false-negative.”
I am so glad Mike Cummings and the BMAS rushed to prove me right.
It’s so nice to know one can rely on someone in these uncertain times!
Alternative medicine (AM) use has become popular among patients with cancer. I find this very easy to understand: faced with such a grave diagnosis, who would not be tempted to try everything that is being promoted as being helpful. And, by Jove, promoted it is! But does it do any good?
The evidence clearly shows that no form of AM is capable of changing the natural history of any form of cancer. This means the millions of websites that imply otherwise are criminally wrong and frightfully dangerous.
But some AMs might still be useful, namely for improving symptoms, well-being and quality of life (QOL) as supportive or palliative therapies. Unfortunately the evidence for this assumption is less sound than AM fans try to make us believe. Before this background, better research is needed and more trials would be welcome. A brand-new paper might tell us more.
The purposes of this study were to compare the QOL in CAM users and non-CAM users and to determine whether AM use influences QOL among breast cancer patients during chemotherapy.
A cross-sectional survey was conducted at two outpatient chemotherapy centers. A total of 546 patients completed the questionnaires on AM use. QOL was evaluated based on the European Organization for Research and Treatment of Cancer (EORTC) core quality of life (QLQ-C30) and breast cancer-specific quality of life (QLQ-BR23) questionnaires.
A total of 70.7% of patients were identified as AM users. There was no significant difference in global health status scores and in all 5 subscales of the QLQ C30 functional scales between AM users and non-AM users. On the QLQ-C30 symptom scales, AM users (44.96±3.89) had significantly (p = 0.01) higher mean scores for financial difficulties than non-AM users (36.29±4.81). On the QLQ-BR23 functional scales, AM users reported significantly higher mean scores for sexual enjoyment (6.01±12.84 vs. 4.64±12.76, p = 0.04) than non-AM users. On the QLQ-BR23 symptom scales, AM users reported higher systemic therapy side effects (41.34±2.01 vs. 37.22±2.48, p = 0.04) and breast symptoms (15.76±2.13 vs. 11.08±2.62, p = 0.02) than non-AM users. Multivariate logistic regression analysis indicated that the use of CAM modality was not significantly associated with higher global health status scores (p = 0.71).
The authors drew the following conclusions: While the findings indicated that there was no significant difference between users and non-users of AM in terms of QOL, AM may be used by health professionals as a surrogate to monitor patients with higher systemic therapy side effects and breast symptoms. Furthermore, given that AM users reported higher financial burdens (which may have contributed to increased distress), patients should be encouraged to discuss the potential benefits and/or disadvantages of using AM with their healthcare providers.
One needs to caution, of course, that this was not an RCT, and therefore cause and effect cannot be taken for granted. Nevertheless, I believe, that these findings should make us think critically about the wide-spread notion that the supportive and palliative use of AM leads to an improvement of QOL in cancer patients.
Wet cupping is a therapy traditionally used in several cultures. It involves superficial injuries to the skin and subsequently the application of a vacuum cup over the injured site. This procedure would draw a small amount of blood into the cup, and this visible effect was taken as a sign that the humors or life forces or whatever are being restored.
The treatment is obviously painful and carries the risk of infection. But does it work? There are not many clinical trials of this form of alternative medicine, and I was therefore thrilled to find a new paper with a randomised clinical trial.
The aim of this clinical trial was to evaluate the effectiveness and safety of wet cupping therapy as the sole treatment for persistent nonspecific low back pain (PNSLBP). The investigators recruited 80 with PNSLBP lasting at least 3 months and randomly allocated them to an intervention group (n=40) or to a control group (n=40). The experimental group had 6 wet cupping sessions within 2 weeks, each of which were done at two bladder meridian (BL) acupuncture points. The control group had no such treatments. Acetaminophen was allowed as a rescue treatment in both groups. The Numeric Rating Scale (NRS), McGill Present Pain Intensity (PPI), and Oswestry Disability Questionnaire (ODQ) were used as outcome measures. Numbers of acetaminophen tablets taken were compared at 4 weeks from baseline. Adverse events were recorded.
At the end of the intervention, statistically significant differences in all three outcome measures favouring the wet cupping group compared with the control group were seen. These improvements continued for another two weeks after the end of the intervention. Acetaminophen was used less in the wet cupping group, but this difference was not statistically significant. No adverse events were reported.
The authors concluded that wet cupping is potentially effective in reducing pain and improving disability associated with PNSLBP at least for 2 weeks after the end of the wet cupping period. Placebo-controlled trials are needed.
Every now and then – well, actually in alternative medicine this is not so rare an event – I come across a study that ‘smells to high heaven’. This one certainly does; to be precise, it has the stench of TOO GOOD TO BE TRUE.
Apart from the numerous weaknesses of the study design, there is the fact that the results are do simply not seem plausible. Low back pain has a natural history that is well-studied. We therefore know that the majority of cases do get better fairly quickly regardless of whether we treat them or not. In this study, the control group did not improve at all, as shown on the impressive graph below (the grey line depicts the symptoms in the control group and the black one those of the cupping group).
To me, the improvement of the experimental group looks much like one might expect from the natural history of back pain. If this were true, the effect of wet cupping would by close to zero and the conclusion drawn by the authors of this trial would be false-positive.
But why was there no improvement in the control group?
I do not know the answer to this question. All I know is that it is this unexplained phenomenon which has created the impression of effectiveness of wet cupping.
The principal aim of this survey was to map centres across Europe that provide public health services and operating within the national health system in integrative oncology.
Information was received from 123 (52.1 %) of the 236 centres contacted. Forty-seven out of 99 responding centres meeting inclusion criteria (47.5 %) provided integrative oncology treatments, 24 from Italy and 23 from other European countries. The number of patients seen per year was on average 301.2 ± 337. Among the centres providing these kinds of therapies, 33 (70.2 %) use fixed protocols and 35 (74.5 %) use systems for the evaluation of results. Thirty-two centres (68.1 %) were research-active.
The alternative therapies most frequently provided were acupuncture 26 (55.3 %), homeopathy 19 (40.4 %), herbal medicine 18 (38.3 %) and traditional Chinese medicine 17 (36.2 %); anthroposophic medicine 10 (21.3 %); homotoxicology 6 (12.8 %); and other therapies 30 (63.8 %).
Treatments were mainly directed to reduce adverse reactions to chemo-radiotherapy (23.9 %), in particular nausea and vomiting (13.4 %) and leucopenia (5 %). The alternative treatments were also used to reduce pain and fatigue (10.9 %), to reduce side effects of iatrogenic menopause (8.8 %) and to improve anxiety and depression (5.9 %), gastrointestinal disorders (5 %), sleep disturbances and neuropathy (3.8 %).
The authors concluded that mapping of the centres across Europe is an essential step in the process of creating a European network of centres, experts and professionals constantly engaged in the field of integrative oncology, in order to increase, share and disseminate the knowledge in this field and provide evidence-based practice.
WHAT EVIDENCE-BASED PRACTICE?
Where is the evidence that homeopathy or homotoxicology or Chinese medicine are effective for any of the conditions listed above? The answer, of course, is that it does not exist.
I fear the results of this survey show foremost one thing: ‘integrative oncology’ is little else but a smokescreen behind which quacks submit desperate patients to bogus treatments.
A recent comment to a post of mine (by a well-known and experienced German alt med researcher) made the following bold statement aimed directly at me and at my apparent lack of understanding research methodology:
C´mon , as researcher you should know the difference between efficacy and effectiveness. This is pharmacological basic knowledge. Specific (efficacy) + nonspecific effects = effectiveness. And, in fact, everything can be effective – because of non-specific or placebo-like effects. That does not mean that efficacy is existent.
The point he wanted to make is that outcome studies – studies without a control group where the researcher simply observe the outcome of a particular treatment in a ‘real life’ situation – suffice to demonstrate the effectiveness of therapeutic interventions. This belief is very wide-spread in alternative medicine and tends to mislead all concerned. It is therefore worth re-visiting this issue here in an attempt to create some clarity.
When a patient’s condition improves after receiving a therapy, it is very tempting to feel that this improvement reflects the effectiveness of the intervention (as the researcher mentioned above obviously does). Tempting but wrong: there are many other factors involved as well, for instance:
- the placebo effect (mainly based on conditioning and expectation),
- the therapeutic relationship with the clinician (empathy, compassion etc.),
- the regression towards the mean (outliers tend to return to the mean value),
- the natural history of the patient’s condition (most conditions get better even without treatment),
- social desirability (patients tend to say they are better to please their friendly clinician),
- concomitant treatments (patients often use treatments other than the prescribed one without telling their clinician).
So, how does this fit into the statement above ‘Specific (efficacy) + nonspecific effects = effectiveness’? Even if this formula were correct, it would not mean that outcome studies of the nature described demonstrate the effectiveness of a therapy. It all depends, of course, on what we call ‘non-specific’ effects. We all agree that placebo-effects belong to this category. Probably, most experts also would include the therapeutic relationship and the regression towards the mean under this umbrella. But the last three points from my list are clearly not non-specific effects of the therapy; they are therapy-independent determinants of the clinical outcome.
The most important factor here is usually the natural history of the disease. Some people find it hard to imagine what this term actually means. Here is a little joke which, I hope, will make its meaning clear and memorable.
CONVERATION BETWEEN TWO HOSPITAL DOCTORS:
Doc A: The patient from room 12 is much better today.
Doc B: Yes, we stared his treatment just in time; a day later and he would have been cured without it!
I am sure that most of my readers now understand (and never forget) that clinical improvement cannot be equated with the effectiveness of the treatment administered (they might thus be immune to the misleading messages they are constantly exposed to). Yet, I am not at all sure that all ‘alternativists’ have got it.
Reflexology is the treatment of reflex zones, usually on the sole of the feet, with manual massage and pressure. Reflexologists assume that certain zones correspond to certain organs, and that their treatment can influence the function of these organs. Thus reflexology is advocated for all sorts of conditions. Proponents are keen to point out that their approach has many advantages: it is pleasant (the patient feels well with the treatment and the therapist feels even better with the money), safe and cheap, particularly if the patient does the treatment herself.
Self-administered foot reflexology could be practical because it is easy to learn and not difficult to apply. But is it also effective? A recent systematic review evaluated the effectiveness of self-foot reflexology for symptom management.
Participants were healthy persons not diagnosed with a specific disease. The intervention was foot reflexology administered by participants, not by practitioners or healthcare providers. Studies with either between groups or within group comparison were included. The electronic literature searches utilized core databases (MEDLINE, EMBASE, Cochrane, and CINAHL Chinese (CNKI), Japanese (J-STAGE), and Korean databases (KoreaMed, KMbase, KISS, NDSL, KISTI, and OASIS)).
Three non-randomized trials and three before-and-after studies met the inclusion criteria. No RCTs were located. The results of these studies showed that self-administered foot reflexology resulted in significant improvement in subjective outcomes such as perceived stress, fatigue, and depression. However, there was no significant improvement in objective outcomes such as cortisol levels, blood pressure, and pulse rate. We did not find any randomized controlled trial.
The authors concluded that this study presents the effectiveness of self-administered foot reflexology for healthy persons’ psychological and physiological symptoms. While objective outcomes showed limited results, significant improvements were found in subjective outcomes. However, owing to the small number of studies and methodological flaws, there was insufficient evidence supporting the use of self-performed foot reflexology. Well-designed randomized controlled trials are needed to assess the effect of self-administered foot reflexology in healthy people.
I find this review quite interesting, but I would draw very different conclusions from its findings.
The studies that are available turned out to be of very poor methodological quality: they lack randomisation or rely on before/after comparisons. This means they are wide open to bias and false-positive results, particularly in regards to subjective outcome measures. Predictably, the findings of this review confirm that no effects are seen on objective endpoints. This is in perfect agreement with the hypothesis that reflexology is a pure placebo. Considering the biological implausibility of the underlying assumptions of reflexology, this makes sense.
My conclusions of this review would therefore be as follows: THE RESULTS ARE IN KEEPING WITH REFLEXOLOGY BEING A PURE PLACEBO.
Iyengar Yoga, named after and developed by B. K. S. Iyengar, is a form of Hatha Yoga that has an emphasis on detail, precision and alignment in the performance of posture (asana) and breath control (pranayama). The development of strength, mobility and stability is gained through the asanas.
B.K.S. Iyengar has systematised over 200 classical yoga poses and 14 different types of Pranayama (with variations of many of them) ranging from the basic to advanced. This helps ensure that students progress gradually by moving from simple poses to more complex ones and develop their mind, body and spirit step by step.
Iyengar Yoga often makes use of props, such as belts, blocks, and blankets, as aids in performing asanas (postures). The props enable students to perform the asanas correctly, minimising the risk of injury or strain, and making the postures accessible to both young and old.
Sounds interesting? But does it work?
The objective of this recent systematic review was to conduct a systematic review of the existing research on Iyengar yoga for relieving back and neck pain. The authors conducted extensive literature searches and found 6 RCTs that met the inclusion criteria.
The difference between the groups on the post-intervention pain or functional disability intensity assessment was, in all 6 studies, favouring the yoga group, which projected a decrease in back and neck pain.
The authors concluded that Iyengar yoga is an effective means for both back and neck pain in comparison to control groups. This systematic review found strong evidence for short-term effectiveness, but little evidence for long-term effectiveness of yoga for chronic spine pain in the patient-centered outcomes.
So, if we can trust this evidence (I would not call the evidence ‘strong), we have yet another treatment that might be effective for acute back and neck pain. The trouble, I fear, is not that we have too few such treatments, the trouble seems to be that we have too many of them. They all seem similarly effective, and I cannot help but wonder whether, in fact, they are all similarly ineffective.
Regardless of the answer to this troubling question, I feel the need to re-state what I have written many times before: FOR A CONDITION WITH A MULTITUDE OF ALLEGEDLY EFFECTIVE THERAPIES, IT MIGHT BE BEST TO CHOSE THE ONE THAT IS SAFEST AND CHEAPEST.
Homeopathy has many critics who claim that there is no good evidence for this type of therapy. Homeopaths invariably find this most unfair and point to a plethora of studies that show an effect. They are, of course, correct! There are plenty of trials that suggest that homeopathic remedies do work. The question, however, is HOW RELIABLE ARE THESE STUDIES?
Here is a brand new one which might stand for dozens of others.
In this study, homeopaths treated 50 multimorbid patients with homeopathic remedies identifies by a method called ‘polarity analysis’ (PA) and prospectively followed them over one year (PA enables homeopaths to calculate a relative healing probability, based on Boenninghausen’s grading of polar symptoms).
The 43 patients (86%) who completed the observation period experienced an average improvement of 91% in their initial symptoms. Six patients dropped out, and one did not achieve an improvement of 80%, and was therefore also counted as a treatment failure. The cost of homeopathic treatment was 41% of projected equivalent conventional treatment.
Good news then for enthusiasts of homeopathy? 91% improvement!
Yet, I am afraid that critics might not be bowled over. They might smell a whiff of selection bias, lament the lack of a control group or regret the absence of objective outcome measures. But I was prepared to go as far as stating that such results might be quite interesting… until I read the authors’ conclusions that is:
Polarity Analysis is an effective method for treating multimorbidity. The multitude of symptoms does not prevent the method from achieving good results. Homeopathy may be capable of taking over a considerable proportion of the treatment of multimorbid patients, at lower costs than conventional medicine.
Virtually nothing in these conclusions is based on the data provided. They are pure extrapolation and wild assumptions. Two questions seem to emerge from this:
- How on earth can we take this and so many other articles on homeopathy seriously?
- When does this sort of article cross the line between wishful thinking and scientific misconduct?
Reiki is a form of energy healing that evidently has been getting so popular that, according to the ‘Shropshire Star’, even stressed hedgehogs are now being treated with this therapy. In case you argue that this publication is not cutting edge when it comes to reporting of scientific advances, you may have a point. So, let us see what evidence we find on this amazing intervention.
A recent systematic review of the therapeutic effects of Reiki concludes that the serious methodological and reporting limitations of limited existing Reiki studies preclude a definitive conclusion on its effectiveness. High-quality randomized controlled trials are needed to address the effectiveness of Reiki over placebo. Considering that this article was published in the JOURNAL OF ALTERNATIVE AND COMPLEMENTARY MEDICINE, this is a fairly damming verdict. The notion that Reiki is but a theatrical placebo recently received more support from a new clinical trial.
This pilot study examined the effects of Reiki therapy and companionship on improvements in quality of life, mood, and symptom distress during chemotherapy. Thirty-six breast cancer patients received usual care, Reiki, or a companion during chemotherapy. Data were collected from patients while they were receiving usual care. Subsequently, patients were randomized to either receive Reiki or a companion during chemotherapy. Questionnaires assessing quality of life, mood, symptom distress, and Reiki acceptability were completed at baseline and chemotherapy sessions 1, 2, and 4. Reiki was rated relaxing and caused no side effects. Both Reiki and companion groups reported improvements in quality of life and mood that were greater than those seen in the usual care group.
The authors of this study conclude that interventions during chemotherapy, such as Reiki or companionship, are feasible, acceptable, and may reduce side effects.
This is an odd conclusion, if there ever was one. Clearly the ‘companionship’ group was included to see whether Reiki has effects beyond simply providing sympathetic attention. The results show that this is not the case. It follows, I think, that Reiki is a placebo; its perceived relaxing effects are the result of non-specific phenomena which have nothing to do with Reiki per se. The fact that the authors fail to spell this out more clearly makes me wonder whether they are researchers or promoters of Reiki.
Some people will feel that it does not matter how Reiki works, the main thing is that it does work. I beg to differ!
If its effects are due to nothing else than attention and companionship, we do not need ‘trained’ Reiki masters to do the treatment; anyone who has time, compassion and sympathy can do it. More importantly, if Reiki is a placebo, we should not mislead people that some super-natural energy is at work. This only promotes irrationality – and, as Voltaire once said: those who make you believe in absurdities can make you commit atrocities.
The Alexander Technique is a method aimed at re-educating people to do everyday tasks with less muscular and mental tension. According to the ‘Complete Guide to the Alexander Technique’, this method can help you if:
- You suffer from repetitive strain injury or carpal tunnel syndrome.
- You have a backache or stiff neck and shoulders.
- You become uncomfortable when sitting at your computer for long periods of time.
- You are a singer, musician, actor, dancer or athlete and feel you are not performing at your full potential.
Sounds good!? But which of these claims are actually supported by sound evidence.
Our own systematic review from 2003 of the Alexander Technique (AT) found just 4 clinical studies. Only two of these trials were methodologically sound and clinically relevant. Their results were promising and implied that AT is effective in reducing the disability of patients suffering from Parkinson’s disease and in improving pain behaviour and disability in patients with back pain. A more recent review concluded as follows: Strong evidence exists for the effectiveness of Alexander Technique lessons for chronic back pain and moderate evidence in Parkinson’s-associated disability. Preliminary evidence suggests that Alexander Technique lessons may lead to improvements in balance skills in the elderly, in general chronic pain, posture, respiratory function and stuttering, but there is insufficient evidence to support recommendations in these areas.
This suggests that the ‘Complete Guide’ is based more on wishful thinking than on evidence. But what about the value of AT for performers – after all, it is for this purpose that Alexander developed his method?
A recent systematic review aimed to evaluate the evidence for the effectiveness of AT sessions on musicians’ performance, anxiety, respiratory function and posture. The following electronic databases were searched up to February 2014 for relevant publications: PUBMED, Google Scholar, CINAHL, EMBASE, AMED, PsycINFO and RILM. The search criteria were “Alexander Technique” AND “music*”. References were searched, and experts and societies of AT or musicians’ medicine contacted for further publications.
In total, 237 citations were assessed. 12 studies were included for further analysis, 5 of which were randomised controlled trials (RCTs), 5 controlled but not randomised (CTs), and 2 mixed methods studies. Main outcome measures in RCTs and CTs were music performance, respiratory function, performance anxiety, body use and posture. Music performance was judged by external experts and found to be improved by AT in 1 of 3 RCTs; in 1 RCT comparing neurofeedback (NF) to AT, only NF caused improvements. Respiratory function was investigated in 2 RCTs, but not improved by AT training. Performance anxiety was mostly assessed by questionnaires and decreased by AT in 2 of 2 RCTs and in 2 of 2 CTs.
From this evidence, the authors drew the following conclusion: A variety of outcome measures have been used to investigate the effectiveness of AT sessions in musicians. Evidence from RCTs and CTs suggests that AT sessions may improve performance anxiety in musicians. Effects on music performance, respiratory function and posture yet remain inconclusive. Future trials with well-established study designs are warranted to further and more reliably explore the potential of AT in the interest of musicians.
So, there you are: if you are a performing artist, AT seems to be useful for you. If you have health problems (other than perhaps back pain), I would look elsewhere for help.