SynthesisBMJ evidence-based medicine2022
Assessing the magnitude of reporting bias in trials of homeopathy: a cross-sectional study and meta-analysis.
Synthesis in BMJ evidence-based medicine, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 8 papers, 2 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
8 citing papers in PubMed, 2 syntheses or guidelines pooled it, 28 citations in OpenAlex.
- Time to publication for results of clinical trials.The Cochrane database of systematic reviews · 2024Pooled it
- Efficacy of homoeopathic treatment: Systematic review of meta-analyses of randomised placebo-controlled homoeopathy trials for any indication.Systematic reviews · 2023Pooled it
- Homeopathic medication for seasonal allergic rhinitis-a randomised placebo-controlled trial.Frontiers in allergy · 2026Trial
- Clinical research on homeopathic preparations: protocol template for a series of systematic reviews.Systematic reviews · 2026Article
- Framework for evidence synthesis of traditional, complementary and integrative medicine systems incorporating context and complexity, illustrated by the example of homeopathy.Frontiers in public health · 2026Article
- The current state of the quality of homeopathic clinical research.Complementary therapies in medicine · 2025Review
- Supporting study registration to reduce research waste.Nature ecology & evolution · 2024Review
- Yes to pluralistic health system, but no to homeopathy.The Lancet regional health. Southeast Asia · 2023Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
8 authors at 3 institutions in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
objectivesTo assess the magnitude of reporting bias in trials assessing homeopathic treatments and its impact on evidence syntheses.
designA cross-sectional study and meta-analysis. Two persons independently searched Clinicaltrials.gov, the EU Clinical Trials Register and the International Clinical Trials Registry Platform up to April 2019 to identify registered homeopathy trials. To determine whether registered trials were published and to detect published but unregistered trials, two persons independently searched PubMed, Allied and Complementary Medicine Database, Embase and Google Scholar up to April 2021. For meta-analyses, we used random effects models to determine the impact of unregistered studies on meta-analytic results. MAIN OUTCOMES AND MEASURES: We report the proportion of registered but unpublished trials and the proportion of published but unregistered trials. We also assessed whether primary outcomes were consistent between registration and publication. For meta-analyses, we used standardised mean differences (SMDs).
resultsSince 2002, almost 38% of registered homeopathy trials have remained unpublished, and 50% of published randomised controlled trials (RCTs) have not been registered. Retrospective registration was more common than prospective registration. Furthermore, 25% of primary outcomes were altered or changed compared with the registry. Although we could detect a statistically significant trend toward an increase of registrations of homeopathy trials (p=0.001), almost 30% of RCTs published during the past 5 years had not been registered.A meta-analysis stratified by registration status of RCTs revealed substantially larger treatment effects of unregistered RCTs (SMD: -0.53, 95% CI -0.87 to -0.20) than registered RCTs (SMD: -0.14, 95% CI -0.35 to 0.07).
conclusionsRegistration of published trials was infrequent, many registered trials were not published and primary outcomes were often altered or changed. This likely affects the validity of the body of evidence of homeopathic literature and may overestimate the true treatment effect of homeopathic remedies.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.