Homeopathy can offer empirical insights on treatment effects in a null field, 2023, Sigurdson et al

Journal of Clinical Epidemiology

Homeopathy can offer empirical insights on treatment effects in a null field

Matthew K Sigurdson, Kristin L Sainani, John P A Ioannidis

Abstract

Objectives: A "null field" is a scientific field where there is nothing to discover and where observed associations are thus expected to simply reflect the magnitude of bias. We aimed to characterize a null field using a known example, homeopathy (a pseudoscientific medical approach based on using highly diluted substances), as a prototype.

Study design: We identified 50 randomized placebo-controlled trials of homeopathy interventions from highly-cited meta-analyses. The primary outcome variable was the observed effect size in the studies. Variables related to study quality or impact were also extracted.

Results: The mean effect size for homeopathy was 0.36 standard deviations (Hedges' g; 95% CI: 0.21, 0.51) better than placebo, which corresponds to an odds ratio of 1.94 (95% CI: 1.69, 2.23) in favor of homeopathy. 80% of studies had positive effect sizes (favoring homeopathy). Effect size was significantly correlated with citation counts from journals in the Directory of Open Access Journals and CiteWatch. We identified common statistical errors in 25 studies.

Conclusion: A null field like homeopathy can exhibit large effect sizes, high rates of favorable results, and high citation impact in the published scientific literature. Null fields may represent a useful negative control for the scientific process.

https://pubmed.ncbi.nlm.nih.gov/36736709/ not open access

 

What exactly is a placebo in a study of homeopathy - are the substances insufficiently diluted, or do they use active ones?

 

Looks like someone is taking XKCD seriously.

 

Perhaps this should prompt some reflection on trials of interventions in other fields that are riddled with biases but achieve the same standard deviation of around 0.3 to 0.4 in favour of the intervention.

From the 2008 Cochrane review of CBT for CFS:

 

Oh, the irony of saying that about homeopathy when it applies far more to everything biopsychosocial, which is basically intellectual homeopathy: ideas diluted out of any meaning that no longer have any. Applying the same evaluation to everything BPS would find far greater biases, the field is built entirely out of it and unlike homeopathy, it has the added weight of being officially recognized, which made it coercive, but without any actual oversight or accountability, the very worst features of both.

 

I'm surprised homeopathy is better than a placebo according to many studies. I thought it was no better.

 

Blinding failure. Homeopathy is placebo.

 

There's always bias in trials. Always. Hell, biases. They're not rigorous precisely to keep the churn of fake positives going. There's just no courage to end the Big lie.

And frankly homeopathy studies show this with high certainty. You know there can't be any effect from a sip of water. And yet there are, because the "effects" are all simple artifacts of poor methodology.

Homeopathy is the ultimate placebo, the null comparator. You can easily do a double-blind experiment. And you still get false positives. That's the impact of biases that exist throughout medicine, it has nothing to do with some effect on the patient, the "placebo" is entirely the sum of small errors made by poor methodology, it's just that they're always in favor of something working.

 

Good paper, intellectual exercise for epidemiologists but also calling out homeopathy as a pseudoscience.

I know that the current head of state for UK and Commonwealth believes in it and was the head of their society.
https://www.theguardian.com/uk-news...rles-criticised-continuing-promote-homeopathy