1. Publication Bias : How to Avoid it An Editor's View
Steven R Bailey MD FSCAI, FACC, FAHA
Janey Briscoe Distinguished Professor of Medicine and Radiology
Chairman, Division of Cardiology
UTHSCSA
Editor in Chief
Catheterization and Cardiovascular Interventions

2. Steven R. Bailey, MD Consulting:
Boston Scientific Corporation, Biostar Venture
Grant Support:
Abbott Vascular, SCAI, St. Jude Medical, Inc.

3. Bias
Epidemiologic deviation of results or inferences from the truth, or processes leading to such systematic deviation
any trend in the collection, analysis, interpretation, publication, or review of data that can lead to conclusions that are systematically incorrect
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.

4. Bias, We All Have It
Add Lincoln to this montage

5. Bias in Research Literature Review Study Design Study Execution
Data Collection
Analysis
Interpretation of Results
Publication
Sackett DL. Bias in analytic research. J Chronic Dis 1979;32:51-63

6. Publication Bias
Inappropriate bias can enter the literature when factors other than quality and scientific content influence a researcher’s selection of what to submit for publication, or a journal’s decision whether to publish a paper.
Editorial New methods to deal with publication bias BMJ 2009

7. Types of Bias Related to Publication
Publication bias
Publication or Non-publication of research findings depending upon content and direction (+/-) results
Time Lag Bias
Rapid or delayed submission and publication depending upon content and direction (+/-) results
Multiple Publication (duplicate) bias
Location Bias
Publication according to ease of access or levels of indexing
Modified from Table 10.1 Cochrane Handbook for Systematic Reviews of Interventions

8. Types of Bias Related to Publication
Citation bias
Citation or Non-Citation of research findings depending upon content and direction (+/-) results
Language Bias
Submission and publication in a particular language depending upon content and direction (+/-) results
Outcome Reporting Bias
Selective reporting of some outcomes but not others depending upon content and direction (+/-) results
Modified from Table 10.1 Cochrane Handbook for Systematic Reviews of Interventions

9. Why does it matter? Distorts the scientific record
Cloaks the “truth”
Encourages unnecessary repetition of research
Influences decision making
Physicians care of patients
May cause harm to patients
Costly for the health care systems
Impacts policy makers
A form of scientific and research misconduct

10. Publication Bias Who is to blame?
Wicked researchers?
Very wicked sponsors?
Editors: the wickedest of all?
Reviewers?
Champion Cochrane Lecture 2010

11. Publication Bias: Study Design
Emily Flake New Yorker Magazine

12. Publication Bias: Impact of Editorial Rejection
Investigators reported that failure to submit for publication (on account of either null results, limitations in methodology, loss of interest, or unimportant results) accounted for 39 % of the reasons given for non-publication.
Rejection of a manuscript by an editor was an infrequent reason (9%) for a study remaining unpublished, regardless of the results.
The OR was 2.94 for a study with statistically significant versus null results being submitted .
Easterbrook Lancet :

13. Publication Bias
Trials with positive findings (P < 0.05), or those findings perceived to be” important or striking” had nearly four times the odds of being submitted and published compared to findings that were not statistically significant (P ≥ 0.05) risk ratio of 1.78 (95% CI 1.58 to 1.95),
Two studies found that trials with positive findings also tended to be published more quickly than trials with negative findings (4.7 vs yrs.).
No influence was seen with
size of the trial
source of funding
academic rank
sex of the principal investigator
Hopewell Cochrane Summaries 2009

14. Publication Bias: Impact of Positive Results on Full Publication after Abstract Presentation
'Positive' results resulted in more publications
any 'significant' result showed an association with full publication (RR = 1.30; CI 1.14 to 1.47)
'positive' results defined as a result favoring the experimental treatment (RR =1.17; CI 1.02 to 1.35)
‘positive' results emanating from randomized or controlled clinical trials (RR = 1.18, CI 1.07 to 1.30).
Scherrer DOI:  / MR pub3 2011

15. Publication Bias Impact of Industry Sponsorship
Published research from drug companies is more likely to be favourable to the product
Companies may selectively fund trials
Industry sponsored trials are of similar quality
Sometimes inappropriate comparators are chosen
Publication bias does occur
Lexchin and Bero BMJ 2003;326:

16. Publication Bias Role of Conflicts of Interest
Conditions of Project Support
Study design
Data collection
Analysis
Interpretation of data
Writing the report N

17. Publication Bias Quality of Life Assessments
Studies sponsored by industry were more than twice as likely as studies sponsored by non-industry sources to report ratios below $20, 000/QALY and over three times more likely to report ratios below $50 000/QALY or $ /QALY.
Studies sponsored by industry were also more likely to be of lower methodological quality and to be published in journals with lower impact factors

18. Publication Bias
Publication bias and other related biases can be summarized as statistically significant, 'positive' results being:
more likely to be published (publication bias)
more likely to be published rapidly (time lag bias)
more likely to be published in English (language bias)
more likely to be published more than once (multiple publication bias)
more likely to be cited by others (citation bias)
All of these biases make positive studies easier to find than those with non-significant or negative results

19. Editorial Publication Bias
Editors must make decisions on what is suitable for their journal, and what will be of interest to their readers, limiting complete objectivity
Editors may reject many submitted papers without independent review, representing bias in selecting which papers to send out to reviewers.

20. Editorial Publication Bias
Unacceptable bias occurs when the decision to send a paper for review, or the decision to accept it, is influenced by factors other than the scientific content of the paper or its fit with the scope of the journal.
papers from a particular country
institution
authors’ affiliations
language
gender

21. Publication Bias Impact of Reviewers
Reviewers can exercise bias not only in the decision whether to recommend acceptance or rejection of a paper, but they can also delay its publication.
They might reject or delay acceptance of papers that do not accord with their own beliefs
they might be more likely to accept, or not critically judge, a paper that supports one of their previous findings, or one that cites them extensively.

22. Assessing Publication Bias

23. Publication Bias Improving the System
Publication bias is an important problem that impacts patient care
Strong evidence supports its existence
It is a complex problem with many contributors
There are several ways to reduce its effect
Ultimately responsibility falls to all involved
sponsors of trials
authors
reviewers
editors

24. Publication Bias Improving the System
Responsible authors
Better conduct and reporting of RCTs
Better conduct and reporting of systematic reviews
Strong industry support for methods and models
Clear definition of editorial policies
Vigilant editors and reviewers
Mechanism for “publication” of unpublished trials