Last spring, we reported on the retraction in Clinical and Translational Allergy of a 2011 paper by researchers in Egypt and Finland after “severe problems in the data set” were uncovered. The notice cited an earlier study, from 2009, in Acta Paediatrica, that formed the basis for the subsequent trial.
At the time, the Acta Paediatrica paper still stood. No longer:
The following article from Acta Paediatrica, Omega-3 fatty acids, vitamin C and Zn supplementation in asthmatic children: a randomized self-controlled study, by Mohammed Al Biltagi, Ahmed Abdul Baset, Mohammed Bassiouny, Mohammed Al Kasrawi and Mohammed Attia, published online on 20 January 2009 in Wiley Online Library (http://onlinelibrary.wiley.com) has been retracted by agreement between the authors, the journal Editor-in-Chief, Hugo Lagercrantz, and Blackwell Publishing Ltd. The retraction has been agreed because of unintentional errors in the analysis of the data presented.
Lagercrantz shed a little more light on the matter in an e-mail response to our query:
We were alerted by a Finnish author (see below) who collaborated with Dr Al Biltagi and published an article in 2011, which later on was retracted as it was found to be based on the 2009 article containing flawed data.
“Two months ago I informed you that a 2009 paper published in Acta Pediatrica was based on flawed data, see below.
Our retraction of our 2011 paper (based on the 2009 paper in Acta Pediatrica) was finally published:
This retraction means that large parts of the 2009 paper are also false, since the data set is flawed.
This retraction describes that the data on the vitamin C effect on clinical outcomes (C-ACT and FEV1) was duplicated.
In addition, I found that the data for vitamin C effect on laboratory data was also duplicated (not published in the retraction since the 2011 paper did not deal with lab data).
And the data for zinc effect on clinical outcomes was duplicated (also not published).
I am not an author of the 2009 paper and therefore I cannot retract that paper myself”.
We contacted Dr Al Biltagi, who was initially reluctant to retract his paper. Dr Hemilä then offered to write a Letter to the Editor to be published in Acta Paediatrica and made his intentions clear to Dr Al Biltagi, who thereafter contacted us saying that he was ready to publish a retraction of the article.
The study has been cited twice, according to Thomson Scientific’s Web of Knowledge.
Hat tip: Harvey Marcovitch