MD, PhD, FMedSci, FRSB, FRCP, FRCPEd.

asthma

Today is WORLD ASTHMA DAY, a good opportunity perhaps to revisit a few of our own evaluations of so-called alternative medicine (SCAM) for asthma. Here are the abstracts of some of our systematic reviews on the subject:

YOGA

Objective: The objective of this systematic review was to assess the effectiveness of yoga as a treatment option for asthma.

Method: Seven databases were searched from their inception to October 2010. Randomized clinical trials (RCTs) and non-randomized clinical trials (NRCTs) were considered, if they investigated any type of yoga in patients with asthma. The selection of studies, data extraction, and validation were performed independently by two reviewers.

Results: Six RCTs and one NRCT met the inclusion criteria. Their methodological quality was mostly poor. Three RCTs and one NRCT suggested that yoga leads to a significantly greater reduction in spirometric measures, airway hyperresponsivity, dose of histamine needed to provoke a 20% reduction in forced expiratory volume in the first second, weekly number of asthma attacks, and need for drug treatment. Three RCTs showed no positive effects compared to various control interventions.

Conclusions: The belief that yoga alleviates asthma is not supported by sound evidence. Further, more rigorous trials are warranted.

SPINAL MANIPULATION

Some clinicians believe that spinal manipulation is an effective treatment for asthma. The aim of this systematic review was to critically evaluate the evidence for or against this claim. Four electronic databases were searched without language restrictions from their inceptions to September 2008. Bibliographies and departmental files were hand-searched. The methodological quality of all included studies was assessed with the Jadad score. Only randomised clinical trials of spinal manipulation as a treatment of asthma were included. Three studies met these criteria. All of them were of excellent methodological quality (Jadad score 5) and all used sham-manipulation as the control intervention. None of the studies showed that real manipulation was more effective than sham-manipulation in improving lung function or subjective symptoms. It is concluded that, according to the evidence of the most rigorous studies available to date, spinal manipulation is not an effective treatment for asthma.

ACUPUNCTURE

Contradictory results from randomised controlled trials of acupuncture in asthma suggest both a beneficial and detrimental effect. The authors conducted a formal systematic review and meta-analysis of all randomised clinical trials in the published literature that have compared acupuncture at real and placebo points in asthma patients. The authors searched for trials published in the period 1970-2000. Trials had to measure at least one of the following objective outcomes: peak expiratory flow rate, forced expiratory volume in one second (FEV1) and forced vital capacity. Estimates of the standarised mean difference, between acupuncture and placebo were computed for each trial and combined to estimate the overall effect. Hetereogeneity was investigated in terms of the characteristics of the individual studies. Twelve trials met the inclusion criteria but data from one could not be obtained. Individual patient data were available in only three. Standardised differences between means ranging from 0.071 to 0.133, in favour of acupuncture, were obtained. The overall effect was not conventionally significant and it corresponds to an approximate difference in FEV1 means of 1.7. After exploring hetereogenenity, it was found that studies where bronchoconstriction was induced during the experiment showed a conventionally significant effect. This meta-analysis did not find evidence of an effect of acupuncture in reducing asthma. However, the meta-analysis was limited by shortcomings of the individual trials, in terms of sample size, missing information, adjustment of baseline characteristics and a possible bias against acupuncture introduced by the use of placebo points that may not be completely inactive. There was a suggestion of preferential publication of trials in favour of acupuncture. There is an obvious need to conduct a full-scale randomised clinical trial addressing these limitations and the prognostic value of the aetiology of the disease.

RELAXATION THERAPIES

Background: Emotional stress can either precipitate or exacerbate both acute and chronic asthma. There is a large body of literature available on the use of relaxation techniques for the treatment of asthma symptoms. The aim of this systematic review was to determine if there is any evidence for or against the clinical efficacy of such interventions.

Methods: Four independent literature searches were performed on Medline, Cochrane Library, CISCOM, and Embase. Only randomised clinical trials (RCTs) were included. There were no restrictions on the language of publication. The data from trials that statistically compared the treatment group with that of the control were extracted in a standardised predefined manner and assessed critically by two independent reviewers.

Results: Fifteen trials were identified, of which nine compared the treatment group with the control group appropriately. Five RCTs tested progressive muscle relaxation or mental and muscular relaxation, two of which showed significant effects of therapy. One RCT investigating hypnotherapy, one of autogenic training, and two of biofeedback techniques revealed no therapeutic effects. Overall, the methodological quality of the studies was poor.

Conclusions: There is a lack of evidence for the efficacy of relaxation therapies in the management of asthma. This deficiency is due to the poor methodology of the studies as well as the inherent problems of conducting such trials. There is some evidence that muscular relaxation improves lung function of patients with asthma but no evidence for any other relaxation technique.

HERBAL MEDICINE

Background: Asthma is one of the most common chronic diseases in modern society and there is increasing evidence to suggest that its incidence and severity are increasing. There is a high prevalence of usage of complementary medicine for asthma. Herbal preparations have been cited as the third most popular complementary treatment modality by British asthma sufferers. This study was undertaken to determine if there is any evidence for the clinical efficacy of herbal preparations for the treatment of asthma symptoms.

Methods: Four independent literature searches were performed on Medline, Pubmed, Cochrane Library, and Embase. Only randomised clinical trials were included. There were no restrictions on the language of publication. The data were extracted in a standardised, predefined manner and assessed critically.

Results: Seventeen randomised clinical trials were found, six of which concerned the use of traditional Chinese herbal medicine and eight described traditional Indian medicine, of which five investigated Tylophora indica. Three other randomised trials tested a Japanese Kampo medicine, marihuana, and dried ivy leaf extract. Nine of the 17 trials reported a clinically relevant improvement in lung function and/or symptom scores.

Conclusions: No definitive evidence for any of the herbal preparations emerged. Considering the popularity of herbal medicine with asthma patients, there is urgent need for stringently designed clinically relevant randomised clinical trials for herbal preparations in the treatment of asthma.

BREATHING TECHNIQUES

Breathing techniques are used by a large proportion of asthma sufferers. This systematic review was aimed at determining whether or not these interventions are effective. Four independent literature searches identified six randomized controlled trials. The results of these studies are not uniform. Collectively the data imply that physiotherapeutic breathing techniques may have some potential in benefiting patients with asthma. The safety issue has so far not been addressed satisfactorily. It is concluded that too few studies have been carried out to warrant firm judgements. Further rigorous trials should be carried out in order to redress this situation.

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So, if you suffer from asthma, my advice is to stay away from SCAM. This might be easier said than done because SCAM practitioners are only too willing to lure asthma patients into their cult. In 2003, we have demonstrated this phenomenon by conducting a survey with chiropractors. Here is our short paper in full:

Classic chiropractic theory claims that vertebral subluxation blocks the flow of ‘‘innate intelligence’’ which, in turn, affects the health of asthma patients (1). Chiropractictors often use spinal manipulation (SM) to correct such malalignments and treat asthma (2). Several clinical trials of chiropractic SM exist, but the most rigorous ones are clearly negative (3,4). Chronic medication with corticosteroids can lead to osteoporosis, a condition, which is a contra-indication to chiropractic SM (5). Given this background, we aimed to determine whether chiropractors would advise an asthma patient on long-term corticosteroids (5 years) to try chiropractic as a treatment for this condition.

All 350 e-mail addresses listed at www.interadcom.com/chiro/html were randomised into two groups. A (deceptive) letter from a (fictitious) patient was sent to group A while group B was asked for advice on chiropractic treatment for asthma as part of a research project. Thus, groups A and B were asked the same question in di¡erent contexts: is chiropractic safe and e¡ective for an asthma patient on long-term steroids. After data collection, respondents from group A were informed that the e-mail had been part of a research project.

Of 97 e-mails in group A, we received 31 responses (response rate = 32% (95% CI, 0.23^ 0.41)). Seventy-four per cent (23 respondents) recommended visiting a chiropractor (95% CI, 0.59^ 0.89). Thirty-five per cent (11 respondents) mentioned minimal or no adverse effects of SM (95% CI, 0.18 ^ 0.52). Three chiropractors responded that some adverse e¡ects exist, e.g. risk of bone fracture, or stroke. Two respondents noted that other investigations (X-rays, spinal and neurological examination) were required before chiropractic treatment. Three respondents suggested additional treatments and one warned about a possible connection between asthma and the measles vaccine. Of 77 e-mails sent to group B, we received 16 responses (response rate = 21% (95% CI, 0.17^ 0.25)). Eleven respondents (69%) recommended visiting a chiropractor (95% CI, 0.46 ^ 0.91). Ten respondents mentioned minimal or no adverse effects of SM (95% CI, 0.39^ 0.87). Five chiropractors responded that adverse effects of SM exist (e.g. bone fracture). Five respondents suggested pre-testing the patient to check bone density, allergy, diet, exercise level, hydration and blood. Additional treatments were recommended by three respondents. The pooled results of groups A and B suggested that the majority of chiropractors recommend chiropractic treatment for asthma and the minority mention any adverse effects.

Our results demonstrate that chiropractic advice on asthma therapy is as readily available over the Internet as it is likely to be misleading. The majority of respondents from both groups (72%) recommended chiropractic treatment. This usually entails SM, a treatment modality which has been demonstrated to be ineffective in rigorous clinical trials (3,4,6). The advice may also be dangerous: the minority of the respondents of both groups (17%) caution of the risk of bone fracture. Our findings also suggest that, for the research question asked, a degree of deception is necessary. The response rate in group B was 12% lower than that of group A, and the answers received differed considerably between groups. In group A, 10% acknowledged the possibility of adverse e¡ects, this figure was 33% in group B. In conclusion, chiropractors readily provide advice regarding asthma treatment, which is often not evidence-based and has the potential to put patients at risk.

__________________________

As I stated above: if you suffer from asthma, my advice is to

stay away from SCAM.

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