Clinical trials overview

Systematic reviews of homeopathy clinical trials

The most robust data on efficacy of homeopathy comes from a 2014 meta-analysis of placebo-controlled double-blind randomised controlled trials which found that homeopathic medicines, when prescribed during individualised treatment, are 1.5- to 2.0-times more likely to have a beneficial effect than placebo.¹ 

This study is one of four comprehensive systematic reviews conducted by Dr Robert Mathie within a ten-year programme of work. These reviews made considerable strides in clarifying the evidence base by separately analysing groups of trials according to both the type of treatment (individualised or non-individualised homeopathy) and comparators (whether the control group was given placebo or something ‘other than placebo’).

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When taken collectively, Dr Mathie’s programme of work includes some important positive findings for homeopathy.

Summary of Dr Mathie’s Systematic Review Programme

Individualised homeopathic treatment 

Taken together, the two systematic reviews on individualised homeopathic treatment^1,2 provide the most rigorous and up-to-date assessment of the key question, ‘Does homeopathy work when prescribed as ‘usual care’ by a trained practitioner?’ The answer is clearly ‘yes’ – the data shows individualised homeopathic medicines to have an effect beyond placebo.

Non-individualised homeopathic treatment 

The evidence for non-individualised homeopathy is promising, but less clear. Analysis of 54 placebo-controlled trials showed a small beneficial effect beyond placebo (SMD -0.33; 95% CI -0.44 to -0.21)³ that partially withstood sensitivity analysis and remained positive in 16 of 18 sub-analyses.

Overview of global systematic reviews with meta-analysis

An overview of systematic reviews was published in October 2023⁵. This study included all reviews with meta-analysis comparing homeopathy against placebo for all medical conditions. The body of evidence assessed comprised 4 historical reviews published from 1997 to 2005^6,7,8,9 plus the two reviews on placebo-controlled trials by Mathie et al. (2014 and 2017).

The primary aim was to ask whether meta-analyses of RCTs of homeopathic treatment showed a significant effect distinct from placebo. Using conventional methods for synthesising evidence from multiple reviews, Hamre et al. concluded that the confidence in the cumulative evidence for a significant positive effect for homeopathy beyond placebo is High for individualised homeopathy, Moderate for non-individualised homeopathy and Moderate when both types of homeopathic treatment are analysed together.

These findings lend further credibility to the over-arching positive trend seen in reviews of homeopathy, or as the authors’ state,

“In contrast to frequent claims, the available meta-analyses of
homoeopathy […] show significant positive effects beyond placebo⁵.”
– Dr Harald Hamre, Institute for Applied Epistemology and Medical Methodology at Witten/Herdecke, Germany

Systematic reviews of clinical trials without meta-analysis 

The Australian NHMRC Homeopathy Review¹⁰ published in 2015 includes clinical trials up to 2010 (captured within SRs published up to 3 January 2013) and separates the data by medical condition. The study concluded that there was ‘no reliable evidence’ of effectiveness of homeopathy. This study attracted criticism for its unprecedented and unscientific methodology e.g. for a study to be ‘reliable’ it had to have a minimum of 150 participants and a quality rating of 5/5 on the Jadad scale. This resulted in only 5 of 176 included studies being categorised as ‘reliable’. Following widespread media attention, the NHMRC Chief Executive Prof Anne Kelso made a public statement that, “Contrary to some claims, the review did not conclude that homeopathy was ineffective.”¹¹ NHMRC was investigated by the Commonwealth Ombudsman to answer charges of scientific misconduct in relation to this report, but as no independent scientific expert could be engaged to assess the evidence, no verdict was reached on these charges.

Further research is needed to consolidate and expand the current clinical trial evidence base in homeopathy. However, these systematic reviews and meta-analyses have identified areas of most promise, helping researchers know where to focus their efforts in order to inform decision-makers and patients about the potential of homeopathic treatments.

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