Biased under-reporting of research reflects biased under-submission more than biased editorial rejection

Stephen Senn challenges Ben Goldacre’s assertion in ‘Bad Pharma’ that biased editorial acceptance of reports with ‘positive’ findings is not a cause of biased under-reporting of research. We agree with Senn that biased editorial decisions may contribute to reporting bias, but Senn ignores the evidence that biased decisions by researchers to submit reports for possible publication are the main causes of the problem.

Stephen Senn challenges Ben Goldacre's assertion in 'Bad Pharma' 1 that biased editorial acceptance of reports with 'positive' findings is not a cause of biased under-reporting of research, and concludes that "the prospects for disentangling cause and effect when it comes to publication bias are not great" 2 . Senn apparently overlooks the studies -including controlled experiments -which have investigated reporting biases. These are summarised in an article 3 from which the following is an excerpt: Senn's use of the term 'publication bias' in his commentary suggests that he is restricting it to editorial bias whereas, as indicated above, the origins of reporting bias are largely due to researchers' decisions not to submit, not editorial decisions not to accept. The analyses of observational data cited by Ben Goldacre in his book 'Bad Pharma' 1 do not detect editorial bias, but neither do they support a confident conclusion that no editorial bias exists. However, we believe Goldacre is correct to castigate researchers and research sponsors as being more culpable than editors in betraying their responsibility to the patients who have participated in trials.
The controlled experiments suggest that it is the results of studies, not their quality, that predisposes them to editorial bias. Senn believes that any editorial bias that exists can be 'very plausibly explained' by preferential publication of 'positive' studies, and that it "seems plausible that higher quality studies are more likely to lead to a positive result". Unless he is using the word 'positive' to mean something other than 'a beneficial effect', however, Senn appears to be overlooking substantial evidence challenging the plausibility of his belief (see, for example, reference 22 ). Given the estimated likelihood of new treatments proving superior to standard treatments 23 it surprises us that, "as a statistician" Senn would find this evidence "unpalatable".

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sentence is especially difficult to read because there is a double negation. Splitting the sentence in the statement of Ben Goldacre and the comment of Stephen Senn may help. Also the last sentence of the comment is difficult to understand, especially when the reader is unaware of the conclusion of reference 23.
The second part of the citation of Goldacre "the prospects for disentangling cause and effect when it comes to publication bias are not great" is difficult to understand and, as far as I can see, does not come back in the comment. Consider whether that part can be omitted, or refer to it again at the end of the comment.
The last section starts with 'The controlled experiments'. It is not clear to which experiments this refers. To 'studies -including controlled experiments 'mentioned in the first section?
In conclusion, this is a very important and informative comment. However, the readability should be improved in order to make it better understandable for readers who have not read all previous papers.

I have read this submission. I believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard.
No competing interests were disclosed. Competing Interests: