Paul Glasziou: Still no evidence for homeopathy

When the National Health and Medical Research Council report on homeopathy concluded that “There was no reliable evidence from research in humans that homeopathy was effective for treating the range of health conditions considered” few in conventional medicine were surprised, but the homeopathy community were outraged. As chair of the working party which produced the report I was simply relieved that the arduous journey of sifting and synthesising the evidence was at an end. I had begun the journey with an “I don’t know” attitude, curious about whether this unlikely treatment could ever work. Still, who would have believed that bacteria caused peptic ulcers, or that vaccines for cancers would become routine. So just maybe . . . but I lost interest after looking at the 57 systematic reviews (on 68 conditions), which contained 176 individual studies, and finding no discernible convincing effects beyond placebo.

Of course, with 176 trials we would expect a few p-values under 5% just by chance: 1/20 of 176 is about 9, which luck would class as “statistically significant.” So we relied on replication and systematic reviews to avoid such false positives. The NHMRC did not redo all 63 systematic reviews (which at say $50,000 each would have cost over $3M), but appraised the existing reviews and used them as a window on the body of evidence. Though that body was mixed in size and quality, no clear signal of effectiveness emerged from the higher quality studies.

One surprise to me was the range of conditions that homeopathy had been evaluated in, including rheumatoid arthritis, radiodermatitis, stomatitis (inflammation of the mouth) due to chemotherapy, and human immunodeficiency virus (HIV) infection. What subsequently shocked me more was that organizations promote homeopathy for infectious conditions, such as AIDS in Africa or malaria. Given the current effective treatments, that seems a very dubious activity, and is another example that justifies the NHMRC statement that “People who choose homeopathy may put their health at risk if they reject or delay treatments for which there is good evidence for safety and effectiveness.”

Unsurprisingly, there has been considerable pushback from those who use or sell homeopathic remedies. Indeed, the International Council for Homeopathy is currently leading a fundraising effort: not to fund better research, but to attack the NHMRC document. I can well understand why Samuel Hahnemann—the founder of homeopathy—was dissatisfied with the state of 18th century medicine’s practices, such as blood-letting and purging, and tried to find a better alternative. But I would guess he would be disappointed by the collective failure of homeopathy to carry on his innovative investigations, but instead continue to pursue a therapeutic dead-end.

Competing interests: While I chaired the NHMRC report on homeopathy, the contents of this blog are my own thoughts, and not those of the NHMRC or other committee members.

Paul Glasziou is professor of evidence based medicine at Bond University and a part time general practitioner.