Systematic review of publication bias in studies on publication bias
BMJ 2005; 331 doi: https://doi.org/10.1136/bmj.38478.497164.F7 (Published 18 August 2005) Cite this as: BMJ 2005;331:433
All rapid responses
Rapid responses are electronic comments to the editor. They enable our users to debate issues raised in articles published on bmj.com. A rapid response is first posted online. If you need the URL (web address) of an individual response, simply click on the response headline and copy the URL from the browser window. A proportion of responses will, after editing, be published online and in the print journal as letters, which are indexed in PubMed. Rapid responses are not indexed in PubMed and they are not journal articles. The BMJ reserves the right to remove responses which are being wilfully misrepresented as published articles or when it is brought to our attention that a response spreads misinformation.
From March 2022, the word limit for rapid responses will be 600 words not including references and author details. We will no longer post responses that exceed this limit.
The word limit for letters selected from posted responses remains 300 words.
Publication bias is usually defined as the tendency from authors to
publish studies with significant results (1).
In this paper the authors survey 26 studies on “publication bias”
(2). To our opinion, not all the included studies are dealing with the
real publication bias, e.g., studies on language bias. Moreover, this
review includes studies on both publication bias and abstract-based
publication bias.
These two publication biases should not be merged since abstracts
presented or even only submitted are not representative of research. “Not
interesting results” would even not be submitted in abstract form. From
Easterbrook study we learn than half of studies with “non significant
trend” or “null” outcomes are not presented. When studying abstracts,
statistically significant results are over-represented (64% vs. 54% when
considering all research). (3) Abstract-based publication bias may
underestimate true research-based publication bias.
The field of publication bias has revealed to be broader than
expected. There may be now a need to clearly define publication bias as
well as sub-categories: outcome reporting bias(significant results are
selected among study outcomes to be published) (4), language bias
(significant results are published in english), database bias (significant
results are more easily retrieved through databases) (5), prestige bias
(significant results are published in higher impact factor journal),
redundant publication bias (significant results are published in more than
one paper)…..
What about an “oral presentation bias”?
References
1. Dickersin K. The existence of publication bias and risk factors
for its occurrence. Jama 1990;263:1385-9.
2. Dubben HH, Beck-Bornholdt HP. Systematic review of publication
bias in studies on publication bias. BMJ 2005. doi:
10.1136/bmj.38478.497164.F7
3. Easterbrook PJ, Berlin JA, Gopalan R, Matthews DR. Publication
bias in clinical research. Lancet 1991;337:867-72.
4. Chan AW, Krleza-Jeric K, Schmid I, Altman DG. Outcome reporting
bias in randomized trials funded by the Canadian Institutes of Health
Research. Cmaj 2004;171:735-40.
5. Nieminen P, Isohanni M. Bias against European journals in medical
publication Databases. Lancet 1999;353:1592.
Competing interests:
None declared
Competing interests: No competing interests
Re: What is publication bias ?
Having read with interest the response of Decullier and Chapuis [1]
to Dubben and Beck-Bornholdt [2], we would like to know how precisely they
would define what they call “an oral presentation bias”.
Would Decullier and Chapuis be so kind as to enlighten us?
[1]
http://bmj.bmjjournals.com/cgi/eletters/bmj.38478.497164.F7v1#110095
[2] Dubben and Beck-Bornholdt. Systematic review of publication bias
in studies on publication bias. BMJ 3 June 2005.
http://bmj.bmjjournals.com/cgi/rapidpdf/bmj.38478.497164.F7v1
Competing interests:
None declared
Competing interests: No competing interests