The Retraction of Our Homeopathy ADHS Meta-Analysis Causes a Stir

A reference to an article on and my questions to the author, Hinnerk Feldwisch-Drentrup

On Monday, Nov 6, 2023, an article appeared on, which addresses the retraction of the publication of our homeopathy ADHS meta-analysis. On the occasion of this incident, he also mentions the other two retractions (of the “Vaccines” study [1], which was republished in “Science, Public Health Policy and the Law” after a triple-blinded review [2] and the children’s mask study [3], which was republished in “Environmental Research” after an extensive review in its long version [4]).

The article is a very good example of how one can apparently work journalistically correctly, namely by not making any false statements or providing good evidence for one’s assertions, but still lying. Because there are two kinds of lies: Someone can lie by claiming something false. And someone can lie by omitting or concealing known, true and important facts. In this case, the second form of lie is endemic. It leads very easily to the presumably intended effect, namely the assassination of my character in the view of all those who don’t know me and who don’t have the time or inclination to take a closer look at the matter. This will probably lead to Wikipedia authors finding even more reason to make critical comments in the article about me, which means that the critical citation cat bites its own tail once more.

Feldwisch-Drentrup knows from me what he is hiding, or could easily have found out by doing more research. I had sent him a detailed email with details about this retraction and the meta-analysis, which are not mentioned in the article.

I then sent him the following letter and waited until Monday, Nov 13, 2023, the deadline, for a response. Having received none, I am publishing the letter. If I receive a reply later, I will of course also publish it.

Here is my letter:

Dear Mr. Feldwisch-Drentrup,

I read your article on with interest. As a person affected, please allow me to give you some critical feedback.

You insinuate that our work on homeopathy for ADHD was justifiably withdrawn because it contained three serious errors.

The first, the wrong sign, was indeed a mistake for which I take responsibility and have taken responsibility, both in my email to you and in my blog, in which I have publicly positioned myself on this. What you fail to mention and what I wrote to you in my email: This error is trivial as far as the effect size estimate is concerned, but has an impact on the significance estimate.

You write as if the other two reasons given by the journal are beyond doubt and certain. They are not. I wrote to you about that too. A colleague of mine independently recalculated the effect size of the incriminated study by Oberai and confirmed my calculation. What the authors published and what the retraction justification states – and says we should have adopted – is wrong. Therefore, it is also wrong to state this as a valid justification for retraction. You are hiding that. The same goes for reason number three, the allegedly inconsistent RoB rating.

Then you bring up the other two retraction cases in a journalistic manner. These have nothing to do with this case and do not belong here. But they are of course a potent journalistic means of insinuating: “Walach is a nutcase and knows nothing about science”. That is the subtext of your further remarks.

You fail to mention here that the re-publication of the Vaccines article went through a triple blind peer review, even though you knew this from me. You insinuate that this cannot be valid because anti-vaxxers would publish in the same journal. What you also fail to mention is the fact that our analysis was correct. You pretend that retraction is a fact-based process, which it was not in this case and neither in the other case. You also ignore that the data we used was correct.

So please allow me two questions. Your answer is important for my next steps:

  1. Do you have even one reliable evidence (in figures 1) that our calculation of the “Number Needed to Vaccinate” for mortality from the retracted Vaccines study is wrong, from peer-reviewed scientific studies? A year later, using the long-term data from the Pfizer pivotal study, we calculated that our first analysis was numerically correct, or more precisely, even too friendly, and published that [5]. These are reliable data, generated by Pfizer themselves. They confirm our analysis and dispel the main criticism that we only used pharmacovigilance or naturalistic data. This is because these data were obtained prospectively and experimentally.
  2. Do you know of a single systematic, well-designed observational study that you can name that has done what we have asked for? Namely, carefully survey a prospectively collected cohort to determine how safe and effective the vaccines are?

You say that our second retracted article, the child mask study, has been republished in a modified form. This is also an insinuation. It suggests that we had corrected an error that led to the retraction. There was no error to correct. The retraction was not justified. And we did not publish a modified version, but the detailed long version, because the short version, which was withdrawn, gave rise to misunderstandings. This is because the main critics did not read the small print, in this case the methodological appendix and the correct (!) specifications of the devices we used.

You are doing the same thing here, too: you are insinuating by omitting important facts.

May I ask you four things in conclusion? I would be grateful for an answer. I also sent you what I think is a detailed answer to your question a few days ago:

  1. By criticizing homeopathy as a treatment option for ADHD, you are insinuating that there is something better. In this case probably Ritalin. Do you know of a study or a solid meta-analysis (keyword: Cochrane standard, which you brought into play) that proves that Ritalin is effective for longer than 3 months? The longest study in our portfolio was one year. Do you know of such a study for Ritalin and do you know what the effect size is?
  2. We published a detailed meta-review a year ago [6]. In it, we examined a third of all randomly selected Cochrane reviews to determine whether the intervention tested contained robust data. We found clear positive evidence for 5.6% of all interventions tested, and because it was a random selection of 1/3 of all Cochrane reviews, this can be applied to medicine as a whole. The media and the FAZ have not yet picked up on this finding. It would suggest that not only homeopathy and complementary medicine should be treated critically, but medicine as a whole. Do you see it as your job as a science journalist to bring such knowledge to the readership of the FAZ?
  3. I pointed out in my blog article that Ms. Priesemann’s working group based its analysis regarding the usefulness of the German lockdown on false data and admitted as much. Nevertheless, the analysis has not been withdrawn. Do you think that’s okay? If so, why? If not, would you denounce this misconduct with the same emphasis?
  4. Finally: You, or rather your business partner, write on your website that journalists have a compass and that both of your compasses point in the same direction. Can you tell me where exactly this compass is pointing?

I am looking forward to your reply,

Best regards,

Harald Walach

Sources and literature

  1. Walach H, Klement RJ, Aukema W. Retracted: The Safety of COVID-19 Vaccinations—We Should Rethink the Policy. Vaccines. 2021;9(7):693. doi:
  2. Walach H, Klement RJ, Aukema W. The Safety of COVID-19 Vaccinations — Should We Rethink the Policy? Science, Public Health Policy, and the Law. 2021;3:87-99.
  3. Walach H, Weikl R, Prentice J, Diemer A, Traindl H, Kappes A, et al. Retracted: Experimental assessment of carbon dioxide content in inhaled air with or without face masks in healthy children: A randomized clinical trial. JAMA Pediatrics. 2021. doi:
  4. Walach H, Traindl H, Prentice J, Weikl R, Diemer A, Kappes A, et al. Carbon dioxide rises beyond acceptable safety levels in children under nose and mouth covering: Results of an experimental measurement study in healthy children. Environmental Research. 2022;212:113564. doi:
  5. Walach H, Klement RJ, Aukema W. The risk-benefit ratio of Covid-19 vaccines: Publication policy by retraction does nothing to improve it. Clinical and Translational Discovery. 2022;2(1):e35. doi:
  6. Howick J, Koletsi D, Ioannidis JPA, Madigan C, Pandis N, Loef M, et al. Most healthcare interventions tested in Cochrane Reviews not effective according to high quality evidence: a systematic review and meta-analysis. Journal of Clinical Epidemiology. 2022;148:160-9. doi: