eLetters

43 e-Letters

published between 2017 and 2020

  • Problems associated with not using a true placebo in clinical trials

    The problems associated with NOT using a true placebo in clinical trials - in this case GSK's trial for Cervarix - were discussed way back in 2009:

    FOOD AND DRUG ADMINISTRATION CENTER FOR BIOLOGICS EVALUATION AND RESEARCH

    VACCINES AND RELATED BIOLOGICAL PRODUCTS ADVISORY COMMITTEE

    September 9, 2009

    Pg166

    DR. DEBOLD: I just think in the absence of having a true placebo in the entire study, it is very, very difficult to sort out what the effects are here, what is it that we are really dealing with, what is the baseline, versus what potentially is caused by the so-called controls.

    In this particular study, not only was there two different strengths of Havrix used, there was alum used. In the pooled analysis there were a number of other vaccines used as the control, which makes it scientifically very difficult to sort things out.

  • Retraction notices in PubMed

    I searched PubMed for the retraction notices. The 3 retracted articles published by Elsevier have no retraction notices in PubMed. Retraction notices for the 2 articles in the Journal of the American Society of Hypertension were published in vol. 9, issue 10, this issue is indexed in PubMed and articles citations are in PubMed but the two retraction notices are missing. "Publishers of journals in PubMed must submit citation and abstract" (PubMed FAQ for publishers), these two notices should normally have been submitted by the publisher. As for the article published in the European Journal of Pharmaceutical Sciences, no retraction notice was found, information about the article being retracted is available in the original article but, as no retraction notice seems to be available, there is no information about the retracted status in PubMed. As PubMed is often the source used by researchers doing a study on retractions of articles (e.g. PMID: 28683764, PMID 26797347, PMID: 24928194) it is important to find this information in the database. Publishers should always publish retraction notices for retracted articles and submit the citations to PubMed when the journal is indexed in this database.

  • Response to Brodersen et al’s ’Overdiagnosis: what it is and what it isn’t'

    In their editorial, Brodersen et al. present two types of overdiagnosis. Their two types appear to be identical to two types of overdiagnosis we identified in research published in 2016 (Rogers WA and Mintzker Y. Getting clearer on overdiagnosis. J Eval Clin Prac 2016;22: 580-587). In that paper, we provide a detailed account of maldetection overdiagnosis and misclassification overdiagnosis, together with an analysis of the relevance of these two different types.
    This matter, including our request for a correction, is fully explained in our letter published in this journal: Response to Brodersen et al’s ’Overdiagnosis: what it is and what it isn’t' (http://ebm.bmj.com/content/early/2018/03/29/bmjebm-2018-110948).

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