Tests of the efficacy of homeopathy: Difference between revisions
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'''Tests of the efficacy of homeopathy''' have taken many different forms, with inconsistent outcomes. | {{subpages}} | ||
'''Tests of the efficacy of homeopathy''' have taken many different forms, with inconsistent outcomes. By comparison with contemporary trials of conventional medicines, tests of homeopathic remedies are very small (i.e. on relatively few subjects), and often are poorly controlled (without double-blinding, placebo controls, or objective outcomes). These weaknesses mean that positive results are generally treated with skepticism by scientists and conventional physicians. Positive results are usually reported in the homeopathic literature, and seldom in conventional academic medical journals; the trials referenced here however were all published in the conventional literature. | |||
In the U.S.A., the National Center for Complementary and Alternative Medicine (NCCAM), part of the [[National Institutes of Health]], funds some research into homeopathy. It states that controlled clinical trials of homeopathy have produced mixed results; in some, homeopathy appeared to be no more helpful than a placebo, but in others, more benefits were seen than expected from a placebo.<ref name=NCCAM-HQ8>{{citation | url = http://nccam.nih.gov/health/homeopathy/#q8 | |||
| contribution = What has scientific research found out about whether homeopathy works? | |||
| title = Questions and Answers About Homeopathy | |||
| author = National Center for Complementary and Alternative Medicine}}</ref> | |||
<ref>The funded studies include: | |||
* A study on homeopathy for mild traumatic brain injury. | * A study on [[fibromyalgia]], which showed clinical benefits from individually chosen homeopathic remedies as well as objective differences in EEG readings in homeopathic and placebo subjects. (Bell IR ''et al.'' (2004) Improved clinical status in fibromyalgia patients treated with individualized homeopathic remedies versus placebo, ''Rheumatology'' :1111-7</ref> <ref>Bell IR ''et al.'' (2004) EEG Alpha sensitization in individualized homeopathic treatment of fibromyalgia. ''Int J Neurosci'' 114:1195-220) | ||
* A study on homeopathy for mild traumatic brain injury. (Chapman E ''et al.'' (1999) Homeopathic treatment of mild traumatic brain injury: a randomized, double-blind, placebo-controlled trial ''J Head Trauma Rehab''14:521-42) This pilot study indicate a significant benefit from the homeopathic treatment but requires large-scale, independent replication.)</ref> | |||
NCCAM's acting deputy director, Jack Killen, said, in a ''Newsweek'' article, homeopathy "goes beyond current understanding of chemistry and physics." He added, "There is, to my knowledge, no condition for which homeopathy has been proven to be an effective treatment." <ref name=Newsweek>{{citation | |||
| url = http://www.newsweek.com/id/105581 | |||
| journal = Newsweek | |||
| first = Jerry | last = Adler | |||
| url = http://www. | | title = No Way to Treat the Dying | ||
| date = February 4, 2008}}</ref>. | |||
Cochrane Reviews did a meta-analysis of seven [[randomized controlled trial]]s, three prevention trials (number of participants, <math>N = 2265</math>) and four treatment trials, <math>(N = 1194)</math>. The authors considered only two were statistically adequate, but data from the prevention trials showed no effect. Data from the treatment trials showed enough efficacy that further trials were recommended, but that the remedy could not be recommended for first-line therapy. <ref name=Vickers2006>{{citation | Cochrane Reviews did a meta-analysis of seven [[randomized controlled trial]]s, three prevention trials (number of participants, <math>N = 2265</math>) and four treatment trials, <math>(N = 1194)</math>. The authors considered only two were statistically adequate, but data from the prevention trials showed no effect. Data from the treatment trials showed enough evidence of efficacy that further trials were recommended, but that the remedy could not be recommended for first-line therapy. <ref name=Vickers2006>{{citation | ||
| journal = Cochrane Database Syst Rev. | | journal = Cochrane Database Syst Rev. | ||
| date = 2006 | | date = 2006 | ||
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| title = Homoeopathic Oscillococcinum for preventing and treating influenza and influenza-like syndromes. | | title = Homoeopathic Oscillococcinum for preventing and treating influenza and influenza-like syndromes. | ||
| author = Vickers AJ, Smith C. | | author = Vickers AJ, Smith C. | ||
| doi = DOI: 10.1002/14651858.CD001957.pub3}}</ref> | | doi = DOI: 10.1002/14651858.CD001957.pub3}}</ref> | ||
In the UK, the [[NHS]] recognizes that there have been about 200 randomised controlled trials evaluating homeopathy, some show efficacy of treatment and some don't. They conclude, "Despite the available research, it has proven difficult to produce clear clinical evidence that homeopathy works".<ref name=NHSdirect>{{citation | |||
| url = http://www.nhsdirect.nhs.uk/articles/article.aspx?articleId=197§ionId=27# | |||
| author = NHS Direct | |||
| contribution = Homeopathy | |||
| title = Health Encyclopedia}}</ref> | |||
=== | <!---===Animal trials=== | ||
A meta-analysis of 105 animal trials evaluated the use of homeopathic remedies in the treatment of environmental toxicology.<ref name=Linde1994>{{citation | A meta-analysis of 105 animal trials evaluated the use of homeopathic remedies in the treatment of environmental toxicology.<ref name=Linde1994>{{citation | ||
| author = Linde K ''et al.'' | | author = Linde K ''et al.'' | ||
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| pages = 481-92}}</ref> Of these, 28 studies were considered high quality, and positive effects from homeopathic doses were reported 50% more often than no effects. The authors also noted, "experiments using the 'high' dilution range (by our definition those preparations diluted beyond the presence of original substance) had higher quality evaluations than experiments in lower dilution ranges, making their validity more likely. Second, our reevaluation of results from these studies using the raw data showed that over 70% had positive effects."<!--'''''which authors? Source needed for quote'''''--> | | pages = 481-92}}</ref> Of these, 28 studies were considered high quality, and positive effects from homeopathic doses were reported 50% more often than no effects. The authors also noted, "experiments using the 'high' dilution range (by our definition those preparations diluted beyond the presence of original substance) had higher quality evaluations than experiments in lower dilution ranges, making their validity more likely. Second, our reevaluation of results from these studies using the raw data showed that over 70% had positive effects."<!--'''''which authors? Source needed for quote'''''--> | ||
One group of researchers tested the effects of heavy metals on mice who were given homeopathic doses of these toxic substances after exposure. Using Arsenicum album (arsenic oxide) <math>6C, 30C</math> and/or <math>200C</math> to treat mice who were exposed to crude doses of arsenic, they found that it significantly reduced the cytotoxic effects of arsenic, including the levels of two liver enzymes which are indicators of liver toxicity and both of which are increased as a result of arsenic poisoning. <ref>{{citation | <!---One group of researchers tested the effects of heavy metals on mice who were given homeopathic doses of these toxic substances after exposure. Using Arsenicum album (arsenic oxide) <math>6C, 30C</math> and/or <math>200C</math> to treat mice who were exposed to crude doses of arsenic, they found that it significantly reduced the cytotoxic effects of arsenic, including the levels of two liver enzymes which are indicators of liver toxicity and both of which are increased as a result of arsenic poisoning. <ref>{{citation | ||
| author=Mallick P ''et al.'' | | author=Mallick P ''et al.'' | ||
| year=2003 | | year=2003 | ||
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| journal = BMC Complement Alt Med | | journal = BMC Complement Alt Med | ||
| volume = 3 | | volume = 3 | ||
| page = 7}}</ref> | | page = 7}}</ref>---> | ||
===Randomized controlled trials in humans=== | ===Randomized controlled trials in humans=== | ||
Clinical trials are the "gold standard" for efficacy in mainstream medicine, often creating an impasse with homeopaths who do not find their paradigm compatible with large scale [[randomized controlled trial]]s. | Clinical trials are the "gold standard" for efficacy in mainstream medicine, often creating an impasse with homeopaths who do not find their paradigm compatible with large scale [[randomized controlled trial]]s. Homeopaths assert that homeopathic remedies generally have to be individually prescribed to a sick person based on the totality of symptoms, not just the disease that he/she has been diagnosed with; they therefore argue that many clinical trials are inappropriate tests for homeopathic treatment, but acknowledge that there are sometimes exceptions to the need for individualization (the experience above with ''Oscillococcinum'' is one such exception). | ||
Some individual RCTs have shown no statistically significant effect, while others indicate a positive difference in people receiving homeopathic treatment. There are single RCTs in favor of homeopathy for a number of other conditions, including: respiratory allergies such as [[hayfever]], [[asthma]] and [[perennial allergic rhinitis]], <ref name=Taylor2000>{{citation | author = Taylor MA ''et al.'' | Some individual RCTs have shown no statistically significant effect, while others indicate a positive difference in people receiving homeopathic treatment. There are single RCTs in favor of homeopathy for a number of other conditions, including: respiratory allergies such as [[hayfever]], [[asthma]] and [[perennial allergic rhinitis]], <ref name=Taylor2000>{{citation | author = Taylor MA ''et al.'' | ||
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| year = 1989 | | year = 1989 | ||
| volume = 27 | | volume = 27 | ||
| pages = 329-35 }}</ref> childhood diarrhea,<ref>Jacobs, J | | pages = 329-35 }}</ref> childhood diarrhea,<ref>Jacobs, J ''et al.'' (2003) Homeopathy for Childhood Diarrhea: Combined Results and Metaanalysis from Three Randomized, Controlled Clinical Trials ''Pediatr Infect Dis J'' 22:229-34.</ref> symptoms of chronic obstructive pulmonary disease,<ref>Frass M ''et al.''Influence of potassium dichromate on tracheal secretions in critically ill patients, Chest, 2005.</ref> arthritis,<ref> Jonas, WB ''et al.'' (2000) Homeopathy and rheumatic disease ''Rheumatic Disease Clinics of North America'' 1:117-23</ref> fibromyalgia,<ref>Bell ''et al.''Improved Cilnical Status in Fibromyalgia Patients Treated with Individualized Homeopathic Remedies Versus Placebo, Rheumatology, 2004:1111-7.</ref> <ref>Fisher P ''et al.'' (1989) Effect of homoeopathic treatment on fibrositis (Primary Fibromyalgia) ''BMJ'' 299365-6</ref> vertigo,<ref>Weiser M ''et al.'' (1998) Homeopathic vs. conventional treatment of vertigo: a randomized double-blind controlled clinical study ''Archives Otolaryngol'' 124:879-85</ref> head injuries,<ref>Chapman E ''et al.''(1999) Homeopathic treatment of mild Traumatic brain injury: a randomized, double-blind, placebo-controlled trial ''J Head Trauma Rehab'' 6:521-42</ref> varicose veins <ref>Ernst E ''et al.'' (1990)Complementary treatment of varicose veins - a randomised, placebo-controlled, double-blind trial ''Phlebology'' 5:157-63.</ref> ankle sprain, bronchitis, chronic fatigue and [[premenstrual syndrome]]. | ||
Influence of potassium dichromate on tracheal secretions in critically ill patients, Chest | |||
Some trials have been performed that partially meet these criteria, and some of these have reported positive effects. These have not been considered as providing compelling evidence, partly because of deficiencies in trial design, but mainly because of the possibility of [[publication bias]] - the phenomenon whereby trials that happen by chance to appear to show a positive outcome are more likely to be published than those which are inconclusive or appear to show a negative outcome. | Some trials have been performed that partially meet these criteria, and some of these have reported positive effects. These have not been considered as providing compelling evidence, partly because of deficiencies in trial design, but mainly because of the possibility of [[publication bias]] - the phenomenon whereby trials that happen by chance to appear to show a positive outcome are more likely to be published than those which are inconclusive or appear to show a negative outcome. | ||
Nevertheless, even if homeopaths distrust clinical trials, some have shown, in small groups, enough positive results to justify larger tests. Positive results came from Taylor and colleagues, writing on their placebo-controlled [[randomized controlled trial]] of a homeopathic treatment for [[allergy|allergic rhinitis]], concluded " this study has failed to confirm our original hypothesis that homoeopathy is a placebo". <ref name=Taylor2000 />Two invited commenters were published alongside, and found the study interesting, but of small size. They urged larger trials, and cited the challenge of doing "large trials that really could change thinking," citing work on influenza by Vickers ''et al.'' <ref name=Vickers1998>{{citation | <!---Nevertheless, even if homeopaths distrust clinical trials, some have shown, in small groups, enough positive results to justify larger tests. Positive results came from Taylor and colleagues, writing on their placebo-controlled [[randomized controlled trial]] of a homeopathic treatment for [[allergy|allergic rhinitis]], concluded " this study has failed to confirm our original hypothesis that homoeopathy is a placebo". <ref name=Taylor2000 />Two invited commenters were published alongside, and found the study interesting, but of small size. They urged larger trials, and cited the challenge of doing "large trials that really could change thinking," citing work on influenza by Vickers ''et al.'' <ref name=Vickers1998>{{citation | ||
|author= Vickers AJ ''et al.'' | |author= Vickers AJ ''et al.'' | ||
| title = Homeopathic arnica 30x is ineffective for muscle soreness after long-distance running: a randomized, double-blind, placebo-controlled trial. | | title = Homeopathic arnica 30x is ineffective for muscle soreness after long-distance running: a randomized, double-blind, placebo-controlled trial. | ||
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| volume = 14 | | volume = 14 | ||
| url = http://www.ncbi.nlm.nih.gov/pubmed/9758072 | | url = http://www.ncbi.nlm.nih.gov/pubmed/9758072 | ||
| pages = 227-31}}</ref> and Ferley ''et al.'' | | pages = 227-31}}</ref> and Ferley ''et al.'' on muscle recovery,<ref name=Ferley1989 /> as having done large-scale trials. The muscle soreness trial showed no significant effect of homeopathic treatment; <math>(N =400)</math> but the abstract did not break out the groups. Effects were measured by formal methods of the runners' subjective soreness. | ||
The second trial, on influenza, used the objective endpoint of time to return to normal body temperature as the endpoint. They observed that more people in the active drug group <math>(N=237)</math> than the control group <math>(N=241)</math> had faster recovery <math>(17.1% against 10.3%, P=0.03).</math> While they could not explain the result, they called for "rigorously designed clinical studies." | The second trial, on influenza, used the objective endpoint of time to return to normal body temperature as the endpoint. They observed that more people in the active drug group <math>(N=237)</math> than the control group <math>(N=241)</math> had faster recovery <math>(17.1% against 10.3%, P=0.03).</math> While they could not explain the result, they called for "rigorously designed clinical studies."---> | ||
===Meta-analyses on humans=== | ===Meta-analyses on humans=== | ||
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}}</ref> When considering just those trials of “high quality” and after correcting for publication bias, the findings remained significant ''(means odds ratio of 1.86)'', however, the main conclusion was that the results “were not compatible with the hypothesis that the effects of homeopathy are completely due to placebo.” The authors also concluded that the higher quality trials were less likely to be positive than those of lower quality, saying “There is increasing evidence that more rigorous trials tend to yield less optimistic results than trials with less precautions against bias.” | }}</ref> When considering just those trials of “high quality” and after correcting for publication bias, the findings remained significant ''(means odds ratio of 1.86)'', however, the main conclusion was that the results “were not compatible with the hypothesis that the effects of homeopathy are completely due to placebo.” The authors also concluded that the higher quality trials were less likely to be positive than those of lower quality, saying “There is increasing evidence that more rigorous trials tend to yield less optimistic results than trials with less precautions against bias.” | ||
====Cochrane meta-analysis of Oscillococcinum==== | <!---====Cochrane meta-analysis of Oscillococcinum==== | ||
Oscillococcinum is a commercially available homoeopathic remedy manufactured from wild duck heart and liver that is sold as a remedy for influenza, and which is particularly popular in France. A Cochrane review of seven placebo-controlled studies <ref name=Vickers2006 /> included: | Oscillococcinum is a commercially available homoeopathic remedy manufactured from wild duck heart and liver that is sold as a remedy for influenza, and which is particularly popular in France. A Cochrane review of seven placebo-controlled studies <ref name=Vickers2006 /> included: | ||
*three prevention trials (number of participants <math>(N) = 2265</math>) | *three prevention trials (number of participants <math>(N) = 2265</math>) | ||
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| date = July 26, 2004 | | date = July 26, 2004 | ||
| author = New Zealand Guidelines Group | | author = New Zealand Guidelines Group | ||
| url = http://www.cam.org.nz/Treatment%20Methods/Homoeopathy/oscillococcinum.htm}}</ref> | | url = http://www.cam.org.nz/Treatment%20Methods/Homoeopathy/oscillococcinum.htm}}</ref> The review found "promising" evidence that Oscillococcinum is effective in the treatment of influenza and influenza-like illness, but it was not effective in the prevention of influenza and influenza-like symptoms (<math>(relative risk (RR) 0.64, 95% confidence interval (CI) 0.28 to 1.43).</math>). The review of research found evidence for a small effect on duration of illness (Treatment reduced the duration by 0.28 days <math>(95% CI 0.50 to 0.06).</math>). This positive result from this homeopathic medicine was felt to justify further research, but the review concluded that the data were not strong enough to make a general recommendation to use Oscillococcinum for first-line treatment of influenza.---> | ||
The | ====The ''Lancet'' controversy==== | ||
''See [[Shang reviews of homeopathy]]'' | |||
In 2005, the ''Lancet'' published a meta-analysis of 110 placebo-controlled homoeopathy trials and 110 matched conventional-medicine trials. <ref>{{cite journal | author=Shang A ''et al.''| title=Are the clinical effects of homoeopathy placebo effects? Comparative study of placebo-controlled trials of homoeopathy and allopathy |journal=Lancet |year=2005 |pages=726-32 |volume=366 |id=PMID 16125589| url = http://www.bag.admin.ch/themen/krankenversicherung/00263/00264/04102/index.html?lang=de&download=M3wBUQCu/8ulmKDu36WenojQ1NTTjaXZnqWfVpzLhmfhnapmmc7Zi6rZnqCkkIN0hH2BbKbXrZ2lhtTN34al3p6YrY7P1oah162apo3X1cjYh2+hoJVn6w==}} | In 2005, the ''Lancet'' published a meta-analysis of 110 placebo-controlled homoeopathy trials and 110 matched conventional-medicine trials. <ref>{{cite journal | author=Shang A ''et al.''| title=Are the clinical effects of homoeopathy placebo effects? Comparative study of placebo-controlled trials of homoeopathy and allopathy |journal=Lancet |year=2005 |pages=726-32 |volume=366 |id=PMID 16125589| url = http://www.bag.admin.ch/themen/krankenversicherung/00263/00264/04102/index.html?lang=de&download=M3wBUQCu/8ulmKDu36WenojQ1NTTjaXZnqWfVpzLhmfhnapmmc7Zi6rZnqCkkIN0hH2BbKbXrZ2lhtTN34al3p6YrY7P1oah162apo3X1cjYh2+hoJVn6w==}} | ||
</ref> | </ref> <ref name=Bosely2005>{{citation | ||
| title = As a fourth study says it's no better than a placebo, is this the end for homeopathy? | | title = As a fourth study says it's no better than a placebo, is this the end for homeopathy? | ||
| first = Sarah | last = Boseley | | first = Sarah | last = Boseley | ||
| journal = The Guardian | | journal = The Guardian | ||
| date = August 26 2005 | | date = August 26 2005 | ||
| url = http://www.guardian.co.uk/society/2005/aug/26/health.medicineandhealth3}}</ref>, | | url = http://www.guardian.co.uk/society/2005/aug/26/health.medicineandhealth3}}</ref>. The authors concluded that homeopathy was no better than placebo, and suggested that no further research on homeopathy is necessary. The article was accompanied by an unsigned editorial titled “The end of homeopathy"<ref> Editorial (2005) The end of homeopathy ''Lancet'' 366:690 </ref> and another, signed, editorial.<ref>Vandenbroucke JP (2005) Homoeopathy and ‘the growth of truth’ ''Lancet'' 366:691–2</ref> | ||
While Shang was the lead author, the work was done under the Swiss Complementary Medicine Evaluation Programme (Programm Evaluation Komplementärmedizin, PEK). The outcome suggested that the clinical effects of homeopathic remedies might all be placebo effects. The ''Lancet'' study is notable as a "global" meta-analysis of homeopathy, not an analysis of particular remedies, i.e. it tested the hypothesis that ''all'' of the reported effects of homeopathic remedies are placebo effects. If so, then reports of positive effects reflect publication bias (the tendency to publish results when they show a positive effect but not when they are negative), and the ''magnitude'' of such effects should diminish with sample size and study quality. They analyzed an equal number of conventional medicine trials similarly; these showed a real effect of treatment, in that the size of the reported effect was independent of sample size, but the trials of homeopathy remedies did not. The study does not prove that homeopathy is never effective, but is consistent with the interpretation that all reported effects are placebo effects. The ''Lancet'' subsequently published a selection of critical correspondence. | |||
<!---Advocates of homeopathy assert that this study's emphasis on certain large homeopathic trials lacked [[external validity]], that is, the trials were not consistent with the homeopathic methodology, thereby reducing the meaning of the study's conclusions. Some insight may be gained from a branch of mainstream medicine in which treatment must be far more individualized than any plausible drug trial: surgery. <ref name=Paradis>{{citation | |||
Advocates of homeopathy assert that this study's emphasis on certain large homeopathic trials lacked [[external validity]], that is, the trials were not consistent with the homeopathic methodology, thereby reducing the meaning of the study's conclusions. Some insight may be gained from a branch of mainstream medicine in which treatment must be far more individualized than any plausible drug trial: surgery. <ref name=Paradis>{{citation | |||
| title =Bias in Surgical Research | | title =Bias in Surgical Research | ||
| first = Carmen | last = Paradis | | first = Carmen | last = Paradis | ||
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| volume = 248(2) | | volume = 248(2) | ||
| pages = 180-188 | | pages = 180-188 | ||
| url = http://www.medscape.com/viewarticle/579200_print}}</ref> A trial lacks internal validity when the difference in the control and treatment groups cannot be explained only by the specific different treatment. Paradis gives a hypothetical example of a trial of wound irrigation with an antibiotic. The treatment group has irrigation from a prefilled, mechanically operated fluid dispenser, while the control group's irigation is done with a hand-operated syringe filled with saline. The potential differences are obvious; there can even be more differences in full surgery, due to the differences in anatomy, body fat, and other individual variations. | | url = http://www.medscape.com/viewarticle/579200_print}}</ref> A trial lacks internal validity when the difference in the control and treatment groups cannot be explained only by the specific different treatment. <ref>Paradis gives a hypothetical example of a trial of wound irrigation with an antibiotic. The treatment group has irrigation from a prefilled, mechanically operated fluid dispenser, while the control group's irigation is done with a hand-operated syringe filled with saline. The potential differences are obvious; there can even be more differences in full surgery, due to the differences in anatomy, body fat, and other individual variations.</ref> | ||
External validity is also called "research validation": can the results of controlled trials be seen in community practice? Purists will say that external validation cannot make up for a lack of internal validity; the external experience is essentially separate from the flawed trial. Arguably, many retrospective clinical studies are based purely on reviewing "external" cases, but an attempt is made to find cases with as much similarity as possible. From the perspective of mainstream medicine, it may appear as if homeopaths want to insist on as much individualization as possible, frustrating even retrospective techniques. | External validity is also called "research validation": can the results of controlled trials be seen in community practice? Purists will say that external validation cannot make up for a lack of internal validity; the external experience is essentially separate from the flawed trial. Arguably, many retrospective clinical studies are based purely on reviewing "external" cases, but an attempt is made to find cases with as much similarity as possible. From the perspective of mainstream medicine, it may appear as if homeopaths want to insist on as much individualization as possible, frustrating even retrospective techniques. | ||
External validity, used with care, does guide surgical development; many number of surgical techniques seemed promising at first, but, with a larger data base, proved ineffective, while others gained more credibility. For there to be better understanding between homeopathy and mainstream medicine, there must be mutual willingness to converge on a model where a degree of individual treatment is accepted as part of the homeopathic approach, but the need to have some statistical rigor has to be accepted as part of the approach of evidence-based medicine. | External validity, used with care, does guide surgical development; many number of surgical techniques seemed promising at first, but, with a larger data base, proved ineffective, while others gained more credibility. For there to be better understanding between homeopathy and mainstream medicine, there must be mutual willingness to converge on a model where a degree of individual treatment is accepted as part of the homeopathic approach, but the need to have some statistical rigor has to be accepted as part of the approach of evidence-based medicine. | ||
The conclusion by Shang ''et al.'' that homeopathy is not more effective than a placebo is disputed by proponents of homeopathy. In the ''Journal of Clinical Epidemiology'', Lüdtke and Rutten questioned the parameters used in the Lancet meta-analysis to weigh the value of the trials analysed.<ref name="pmid18834714">{{cite journal |author=Lüdtke R, Rutten AL |title=The conclusions on the effectiveness of homeopathy highly depend on the set of analyzed trials |journal=J Clin Epidemiol |volume=61 |pages=1197–204 |year=2008 |month=December |pmid=18834714 |doi=10.1016/j.jclinepi.2008.06.015 |url=http://linkinghub.elsevier.com/retrieve/pii/S0895-4356(08)00190-X}}</ref> Using other "meaningful subsets", they concluded that "homeopathy had a significant effect beyond placebo" and found, specifically, that "Shang's negative results were mainly influenced by one single trial on preventing muscle soreness in 400 long-distance runners". They concluded: | |||
<blockquote>The meta-analysis results change sensitively to the chosen threshold defining large sample sizes. Because of the high heterogeneity between the trials, Shang's results and conclusions are less definite than had been presented.</blockquote> | |||
---> | |||
====Other Meta-analyses==== | ====Other Meta-analyses==== | ||
Several meta-analyses evaluating the homeopathic treatment of specific diseases | Several meta-analyses evaluating the homeopathic treatment of specific diseases have also found positive results. These studied [[childhood diarrhea]], <ref> Jacobs J ''et al.'' (2003) Homeopathy for childhood diarrhea: combined results and metaanalysis from three randomized, controlled clinical trials. ''Pediatric Infectious Disease Journal'' 22:229–34.</ref> respiratory allergies <ref>Taylor MA ''et al.'' (2000)Randomised Controlled trial of homoeopathy versus placebo in perennial allergic rhinitis with overview of four trial series ''BMJ'' 321:471-76</ref>, | ||
and postoperative [[ileus]]. <ref>Barnes J ''et al.'' (1997) Homeopathy for postoperative ileus? A meta-analysis. ''J Clin Gastroenterol'' 25:628–33</ref> | and postoperative [[ileus]]. <ref>Barnes J ''et al.'' (1997) Homeopathy for postoperative ileus? A meta-analysis. ''J Clin Gastroenterol'' 25:628–33</ref> | ||
In one meta-analysis of 6 trials <math>(N=556)</math>, there were six RCTs, which used different treatments that were difficult to form into a meaningful pool. The authors observed that they used standardized treatment, which probably differs from the homeopathic standard of practice. They observed "There has been only a limited attempt to measure a 'package of care' effect (i.e., the effect of the medication as well as the consultation, which is considered a vital part of individualised homeopathic practice)." The conclusion was that there was not enough useful data, and strongly recommended, in addition to RCTs, collecting "observational data to document the different methods of homeopathic prescribing and how patients respond. This will help to establish to what extent people respond to a 'package of care' rather than the homeopathic intervention alone." <ref name=McCarney2004>{{cite journal |author=McCarney RW ''et al.'' |title=Homeopathy for chronic asthma |journal=Cochrane database of systematic reviews |pages=CD000353 |year=2004 |pmid=14973954 |doi=10.1002/14651858.CD000353.pub2}}</ref> In conventional medicine, there have been comparisons where the actual treatment was the same, but the variable was the type of encounter (e.g., short or long, physician specialist vs. generalist, nurse-educator rather than physician). | In one meta-analysis of 6 trials <math>(N=556)</math>, there were six RCTs, which used different treatments that were difficult to form into a meaningful pool. The authors observed that they used standardized treatment, which probably differs from the homeopathic standard of practice. They observed "There has been only a limited attempt to measure a 'package of care' effect (i.e., the effect of the medication as well as the consultation, which is considered a vital part of individualised homeopathic practice)." The conclusion was that there was not enough useful data, and strongly recommended, in addition to RCTs, collecting "observational data to document the different methods of homeopathic prescribing and how patients respond. This will help to establish to what extent people respond to a 'package of care' rather than the homeopathic intervention alone." <ref name=McCarney2004>{{cite journal |author=McCarney RW ''et al.'' |title=Homeopathy for chronic asthma |journal=Cochrane database of systematic reviews |pages=CD000353 |year=2004 |pmid=14973954 |doi=10.1002/14651858.CD000353.pub2}}</ref> In conventional medicine, there have been comparisons where the actual treatment was the same, but the variable was the type of encounter (e.g., short or long, physician specialist vs. generalist, nurse-educator rather than physician). | ||
Another study | Another study identified 17 useful articles.<ref name=Ernst2002>{{cite journal |author=Ernst E |title=A systematic review of systematic reviews of homeopathy |journal=Br J Clin Pharmacol |volume=54 |pages=577–82 |year=2002 |pmid=12492603 | http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=12492603}}</ref> Six, however, re-analyzed the same major meta-analysis.<ref name=Linde1997 /> This major study observed some differences between homeopathic treatment and placebo, but could find no specific evidence of efficacy for any specific condition. The authors of this meta-analysis defined "evidence" in this context as having at least three independent researchers finding positive results from a specific treatment. <!---Within one year of publication of this meta-analysis, a third independent trial was conducted testing Oscillococcinum in the treatment of influenza. Also, a third trial in the treatment of childhood diarrhea was published (the lead researcher for these trials were the same individual, but the prescribing homeopaths for each trial were different clinicians.) Even though these newer studies helped homeopathic research pass this threshold, the authors of the 1997 meta-analysis still concluded, "Further research on homeopathy is warranted provided it is rigorous and systematic."---> The meta-analysis of the 17 papers concluded "Until more compelling results are available, homeopathy cannot be viewed as an evidence-based form of therapy." <ref name=Ernst2002 /> | ||
====Are the right things being analyzed?==== | ====Are the right things being analyzed?==== | ||
An observation from some authors was that a key element missed in many studies was a systematic observation of the the interaction between homeopath and patient, in contrast with the interaction between patient and conventional health care worker. In conventional medicine, there is concern within the U.S. healthcare economics area about even collecting minimal data on the quality of encounters. One policy study stressed the need not to understand the nature of the interaction, but even to get basic demographics on the encounter;<ref name=McGlynn2008> {{citation | An observation from some authors was that a key element missed in many studies was a systematic observation of the the interaction between homeopath and patient, in contrast with the interaction between patient and conventional health care worker. In conventional medicine, there is concern within the U.S. healthcare economics area about even collecting minimal data on the quality of encounters. One policy study stressed the need not to understand the nature of the interaction, but even to get basic demographics on the encounter;<ref name=McGlynn2008> {{citation | ||
Line 165: | Line 155: | ||
| year = 2007 | | year = 2007 | ||
|url = http://www.aamcn.org/Guidelines_Final%20Draft.pdf}}</ref> It is not unreasonable to note that a number of nursing associations call for more holistic patient interactions than is typical for conventional medicine, and to wonder if there most important lessons from current homeopathy, which are not being studied. | |url = http://www.aamcn.org/Guidelines_Final%20Draft.pdf}}</ref> It is not unreasonable to note that a number of nursing associations call for more holistic patient interactions than is typical for conventional medicine, and to wonder if there most important lessons from current homeopathy, which are not being studied. | ||
<!---==Asthma== | |||
Some studies on the homeopathic treatment of asthma have had positive results<ref>Launsø L ''et al.'' (2006) An exploratory retrospective study of people suffering from hypersensitivity illness who attend medical or classical homeopathic treatment. ''Homeopathy'' 95:73-80.[http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WXX-4JKC4CJ-4&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=0c86a31c6e1b59e0f450a0239d007fa2]</ref> <ref>Matusiewicz R (1997) The effect of a homeopathic preparation on the clinical condition of patients with corticosteroid-dependent bronchial asthma ''Int J Biol Ther Integr Med'' 15:70-4[http://ccrhindia.org/bronchial_asthma/homoeopathic_preparation.htm]</ref> <ref>Reilly, D ''et al.'' (1994) Is evidence for homoeopathy reproducible? ''Lancet''344:1601-6 PMID 7983994</ref> <ref>Riveron-Garrote, M, “Ensayo clinico aleatorizado controlado del tratamento homepatico del asma bronquial,” Boletin Mexicano, 1998,31:54-61.</ref> | |||
However, a review of research on the homeopathic treatment of people with chronic asthma did not find "strong evidence" of efficacy.<ref>McCarney, RW; Linde, K; Lasserson, TJ. Homeopathy for chronic asthma. Cochrane Database Syst Rev. 2004 CD000353.</ref> | |||
The homeopathic studies typically test relatively small numbers of subjects. In comparison, conventional trials treat with hundreds, and surveillance on the actual use in practice gives data from millions. <ref name="NAEP">{{citation | |||
| author=National Asthma Education and Prevention Program | |||
| title = Expert Panel Report III: Guidelines for the diagnosis and management of asthma| publisher = National Heart, Lung, and Blood Institute, 2007. |id = NIH publication no. 08-4051 | |||
| url = http://www.nhlbi.nih.gov/guidelines/asthma/asthgdln.htm}}</ref>. Large studies are difficult because individualized remedy selection is generally essential in homeopathy; this limitation causes conflict with physicians who expect the statistical power of large studies.---> | |||
==References== | |||
{{reflist|2}} |
Revision as of 11:19, 17 August 2024
Tests of the efficacy of homeopathy have taken many different forms, with inconsistent outcomes. By comparison with contemporary trials of conventional medicines, tests of homeopathic remedies are very small (i.e. on relatively few subjects), and often are poorly controlled (without double-blinding, placebo controls, or objective outcomes). These weaknesses mean that positive results are generally treated with skepticism by scientists and conventional physicians. Positive results are usually reported in the homeopathic literature, and seldom in conventional academic medical journals; the trials referenced here however were all published in the conventional literature.
In the U.S.A., the National Center for Complementary and Alternative Medicine (NCCAM), part of the National Institutes of Health, funds some research into homeopathy. It states that controlled clinical trials of homeopathy have produced mixed results; in some, homeopathy appeared to be no more helpful than a placebo, but in others, more benefits were seen than expected from a placebo.[1]
[2] [3] NCCAM's acting deputy director, Jack Killen, said, in a Newsweek article, homeopathy "goes beyond current understanding of chemistry and physics." He added, "There is, to my knowledge, no condition for which homeopathy has been proven to be an effective treatment." [4].
Cochrane Reviews did a meta-analysis of seven randomized controlled trials, three prevention trials (number of participants, ) and four treatment trials, . The authors considered only two were statistically adequate, but data from the prevention trials showed no effect. Data from the treatment trials showed enough evidence of efficacy that further trials were recommended, but that the remedy could not be recommended for first-line therapy. [5]
In the UK, the NHS recognizes that there have been about 200 randomised controlled trials evaluating homeopathy, some show efficacy of treatment and some don't. They conclude, "Despite the available research, it has proven difficult to produce clear clinical evidence that homeopathy works".[6]
Randomized controlled trials in humans
Clinical trials are the "gold standard" for efficacy in mainstream medicine, often creating an impasse with homeopaths who do not find their paradigm compatible with large scale randomized controlled trials. Homeopaths assert that homeopathic remedies generally have to be individually prescribed to a sick person based on the totality of symptoms, not just the disease that he/she has been diagnosed with; they therefore argue that many clinical trials are inappropriate tests for homeopathic treatment, but acknowledge that there are sometimes exceptions to the need for individualization (the experience above with Oscillococcinum is one such exception).
Some individual RCTs have shown no statistically significant effect, while others indicate a positive difference in people receiving homeopathic treatment. There are single RCTs in favor of homeopathy for a number of other conditions, including: respiratory allergies such as hayfever, asthma and perennial allergic rhinitis, [7] acute otitis media, influenza,[8] childhood diarrhea,[9] symptoms of chronic obstructive pulmonary disease,[10] arthritis,[11] fibromyalgia,[12] [13] vertigo,[14] head injuries,[15] varicose veins [16] ankle sprain, bronchitis, chronic fatigue and premenstrual syndrome.
Some trials have been performed that partially meet these criteria, and some of these have reported positive effects. These have not been considered as providing compelling evidence, partly because of deficiencies in trial design, but mainly because of the possibility of publication bias - the phenomenon whereby trials that happen by chance to appear to show a positive outcome are more likely to be published than those which are inconclusive or appear to show a negative outcome.
Meta-analyses on humans
Some authors of meta-analyses have concluded that the placebo response is an inadequate explanation for the positive responses that have been reported in some trials. For example, one review [17] assessed 105 trials, 81 of them positive; the authors concluded that the evidence on balance is that trials are positive but not sufficient to draw definite conclusions, and they said that “based on this evidence we would be ready to accept that homeopathy can be efficacious, if only the mechanism of action were more plausible”.
In another review, Linde and colleagues analyzed 89 trials and found a mean odds ratio of 2.45 (95% confidence interval, 2.05–2.93) in favor of homeopathy.[18] When considering just those trials of “high quality” and after correcting for publication bias, the findings remained significant (means odds ratio of 1.86), however, the main conclusion was that the results “were not compatible with the hypothesis that the effects of homeopathy are completely due to placebo.” The authors also concluded that the higher quality trials were less likely to be positive than those of lower quality, saying “There is increasing evidence that more rigorous trials tend to yield less optimistic results than trials with less precautions against bias.”
The Lancet controversy
See Shang reviews of homeopathy
In 2005, the Lancet published a meta-analysis of 110 placebo-controlled homoeopathy trials and 110 matched conventional-medicine trials. [19] [20]. The authors concluded that homeopathy was no better than placebo, and suggested that no further research on homeopathy is necessary. The article was accompanied by an unsigned editorial titled “The end of homeopathy"[21] and another, signed, editorial.[22]
While Shang was the lead author, the work was done under the Swiss Complementary Medicine Evaluation Programme (Programm Evaluation Komplementärmedizin, PEK). The outcome suggested that the clinical effects of homeopathic remedies might all be placebo effects. The Lancet study is notable as a "global" meta-analysis of homeopathy, not an analysis of particular remedies, i.e. it tested the hypothesis that all of the reported effects of homeopathic remedies are placebo effects. If so, then reports of positive effects reflect publication bias (the tendency to publish results when they show a positive effect but not when they are negative), and the magnitude of such effects should diminish with sample size and study quality. They analyzed an equal number of conventional medicine trials similarly; these showed a real effect of treatment, in that the size of the reported effect was independent of sample size, but the trials of homeopathy remedies did not. The study does not prove that homeopathy is never effective, but is consistent with the interpretation that all reported effects are placebo effects. The Lancet subsequently published a selection of critical correspondence.
Other Meta-analyses
Several meta-analyses evaluating the homeopathic treatment of specific diseases have also found positive results. These studied childhood diarrhea, [23] respiratory allergies [24], and postoperative ileus. [25]
In one meta-analysis of 6 trials , there were six RCTs, which used different treatments that were difficult to form into a meaningful pool. The authors observed that they used standardized treatment, which probably differs from the homeopathic standard of practice. They observed "There has been only a limited attempt to measure a 'package of care' effect (i.e., the effect of the medication as well as the consultation, which is considered a vital part of individualised homeopathic practice)." The conclusion was that there was not enough useful data, and strongly recommended, in addition to RCTs, collecting "observational data to document the different methods of homeopathic prescribing and how patients respond. This will help to establish to what extent people respond to a 'package of care' rather than the homeopathic intervention alone." [26] In conventional medicine, there have been comparisons where the actual treatment was the same, but the variable was the type of encounter (e.g., short or long, physician specialist vs. generalist, nurse-educator rather than physician).
Another study identified 17 useful articles.[27] Six, however, re-analyzed the same major meta-analysis.[18] This major study observed some differences between homeopathic treatment and placebo, but could find no specific evidence of efficacy for any specific condition. The authors of this meta-analysis defined "evidence" in this context as having at least three independent researchers finding positive results from a specific treatment. The meta-analysis of the 17 papers concluded "Until more compelling results are available, homeopathy cannot be viewed as an evidence-based form of therapy." [27]
Are the right things being analyzed?
An observation from some authors was that a key element missed in many studies was a systematic observation of the the interaction between homeopath and patient, in contrast with the interaction between patient and conventional health care worker. In conventional medicine, there is concern within the U.S. healthcare economics area about even collecting minimal data on the quality of encounters. One policy study stressed the need not to understand the nature of the interaction, but even to get basic demographics on the encounter;[28]especially in programs servicing low-income populations, there may be little more than billing data. There are a number of trial programs to use nurses and other providers, at a lower cost than physicians, to do case management of chronic disease. Case management interactions may be as long as some of those with homeopaths.[29] It is not unreasonable to note that a number of nursing associations call for more holistic patient interactions than is typical for conventional medicine, and to wonder if there most important lessons from current homeopathy, which are not being studied.
References
- ↑ National Center for Complementary and Alternative Medicine, What has scientific research found out about whether homeopathy works?, Questions and Answers About Homeopathy
- ↑ The funded studies include:
- A study on fibromyalgia, which showed clinical benefits from individually chosen homeopathic remedies as well as objective differences in EEG readings in homeopathic and placebo subjects. (Bell IR et al. (2004) Improved clinical status in fibromyalgia patients treated with individualized homeopathic remedies versus placebo, Rheumatology :1111-7
- ↑ Bell IR et al. (2004) EEG Alpha sensitization in individualized homeopathic treatment of fibromyalgia. Int J Neurosci 114:1195-220)
- A study on homeopathy for mild traumatic brain injury. (Chapman E et al. (1999) Homeopathic treatment of mild traumatic brain injury: a randomized, double-blind, placebo-controlled trial J Head Trauma Rehab14:521-42) This pilot study indicate a significant benefit from the homeopathic treatment but requires large-scale, independent replication.)
- ↑ Adler, Jerry (February 4, 2008), "No Way to Treat the Dying", Newsweek
- ↑ Vickers AJ, Smith C. (2006), "Homoeopathic Oscillococcinum for preventing and treating influenza and influenza-like syndromes.", Cochrane Database Syst Rev., DOI:10.1002/14651858.CD001957.pub3 DOI: 10.1002/14651858.CD001957.pub3
- ↑ NHS Direct, Homeopathy, Health Encyclopedia
- ↑ Taylor MA et al. (2000), "Randomised controlled trials of homoeopathy versus placebo in perennial allergic rhinitis with overview of four trial series", British Medical Journal 321: 471–6
- ↑ Ferley JP et al. (1989), "A controlled evaluation of a homoeopathic preparation in the treatment of influenza-like syndromes", Br J Clin Pharmacol 27: 329-35
- ↑ Jacobs, J et al. (2003) Homeopathy for Childhood Diarrhea: Combined Results and Metaanalysis from Three Randomized, Controlled Clinical Trials Pediatr Infect Dis J 22:229-34.
- ↑ Frass M et al.Influence of potassium dichromate on tracheal secretions in critically ill patients, Chest, 2005.
- ↑ Jonas, WB et al. (2000) Homeopathy and rheumatic disease Rheumatic Disease Clinics of North America 1:117-23
- ↑ Bell et al.Improved Cilnical Status in Fibromyalgia Patients Treated with Individualized Homeopathic Remedies Versus Placebo, Rheumatology, 2004:1111-7.
- ↑ Fisher P et al. (1989) Effect of homoeopathic treatment on fibrositis (Primary Fibromyalgia) BMJ 299365-6
- ↑ Weiser M et al. (1998) Homeopathic vs. conventional treatment of vertigo: a randomized double-blind controlled clinical study Archives Otolaryngol 124:879-85
- ↑ Chapman E et al.(1999) Homeopathic treatment of mild Traumatic brain injury: a randomized, double-blind, placebo-controlled trial J Head Trauma Rehab 6:521-42
- ↑ Ernst E et al. (1990)Complementary treatment of varicose veins - a randomised, placebo-controlled, double-blind trial Phlebology 5:157-63.
- ↑ Kleijnen J et al.(1991) Clinical trials of homeopathy. British Medical Journal 302:316–23.
- ↑ 18.0 18.1 Linde K et al., "Are the clinical effects of homoeopathy placebo effects? A meta-analysis of placebo-controlled trials", Lancet 350: 834–43
- ↑ Shang A et al. (2005). "Are the clinical effects of homoeopathy placebo effects? Comparative study of placebo-controlled trials of homoeopathy and allopathy". Lancet 366: 726-32. PMID 16125589.
- ↑ Boseley, Sarah (August 26 2005), "As a fourth study says it's no better than a placebo, is this the end for homeopathy?", The Guardian
- ↑ Editorial (2005) The end of homeopathy Lancet 366:690
- ↑ Vandenbroucke JP (2005) Homoeopathy and ‘the growth of truth’ Lancet 366:691–2
- ↑ Jacobs J et al. (2003) Homeopathy for childhood diarrhea: combined results and metaanalysis from three randomized, controlled clinical trials. Pediatric Infectious Disease Journal 22:229–34.
- ↑ Taylor MA et al. (2000)Randomised Controlled trial of homoeopathy versus placebo in perennial allergic rhinitis with overview of four trial series BMJ 321:471-76
- ↑ Barnes J et al. (1997) Homeopathy for postoperative ileus? A meta-analysis. J Clin Gastroenterol 25:628–33
- ↑ McCarney RW et al. (2004). "Homeopathy for chronic asthma". Cochrane database of systematic reviews: CD000353. DOI:10.1002/14651858.CD000353.pub2. PMID 14973954. Research Blogging.
- ↑ 27.0 27.1 Ernst E (2002). "A systematic review of systematic reviews of homeopathy". Br J Clin Pharmacol 54: 577–82. PMID 12492603.
- ↑ McGlynn, EA (April 2008), "[http://www.ahrq.gov/qual/efficiency/efficiency.pdf Final Report: Identifying, Categorizing, and Evaluating Health Care Efficiency Measures]", Southern California Evidence-based Practice Center—RAND Corporation, Santa Monica, CA, AHRQ Publication No. 08-0030
- ↑ Care Management Institute Committee, American Association of Managed Care Nurses (AAMCN) (2007), Care Management Guidelines