This is an in-depth analysis of the evidence behind the scientific peer review process. This is often taken for granted, but is subject to many biases and issues. First published online only October 2008.
Peer Review in Science
What is It, Does it Work, How Should It Evolve?
Alex J Mitchell, University of Leicester email@example.com
About Medical Publishing
Gutenburg publishing, increasing output
Slide Credit: Robert Gorter – Regional Manager Elsevier, 2008
Increase in Scientific Output
Publish Publish Publish!
Tony and Sam were pleased with their output for 2007
Author’s View of What’s Important
90 Refs' comments
70 Referees identified
50 Public commentary on
30 Post-publication public
10 Ability to submit
History of Peer Review
• “Peer Review” of any type goes back to the
17th century and beyond; example “The
• Inquisition of the Holy Roman and Catholic Church”. Scholars’
works were examined for any hints of “heresy”.
• The first recorded academic peer review process was at The
Royal Society in 1665 by the founding editor of Philosophical
Transactions of the Royal Society, Henry Oldenburg, soon
followed by “Medical Essays and Observations” published by
the Royal Society of Edinburgh in 1731.
•Ray Spier (2002), quot;The history of the peer-review processquot;, Trends in Biotechnology 20 (8), p. 357-358 .
• Peer Review Process (defn from Wikipedia)
– Peer review (also known as refereeing) is the process of subjecting an
author's scholarly work, research or ideas to the scrutiny of others who are
experts in the same field.
– Peer review requires a willing and able community of experts who give
impartial feedback, with no personal credit and no financial or other reward.
• Peer Review Journal
– A peer-reviewed journal is one that has submitted most of its published
articles for review by experts who are not part of the editorial staff. The
numbers and kinds of manuscripts sent for review, the number of reviewers,
the reviewing procedures and the use made of the reviewers’
– (International Committee of Medical Journal Editors. Uniform Requirements for Manuscripts submitted to Biomedical
Journals. 2001 http://www.icmje.org/)
Types of Peer Review
Internal vs External
An internal review is conducted only by editorial staff
An external review is conducted by experts in the field
Blind vs Open
In Blind Peer Review submitted manuscripts are sent outside of the journal’s
publishing or sponsoring organization for review by external reviewers
whose identifies are hidden
In Open Peer Review reviewers disclose their identity. Often authors are
encouraged to suggest possible reviewers who are may or may not be
Examples of Problems with Peer Review
• Famous papers that were published and did NOT get peer reviewed:
– Watson & Crick’s 1951 paper on the structure of DNA in Nature
– Abdus Salam’s paper “Weak and electromagnetic interactions” (1968). Led to Nobel Prize
– Alan Sokal’s “Transgressing the Boundaries...” in 1996 turned out to be a hoax. Now known as the
– Albert Einstein's revolutionary quot;Annus Mirabilisquot; papers in the 1905 issue of Annalen der Physik were
only reviewed by the editor
• Famous papers that were published and passed peer review that later proved to be fraudulent:
– Jan Hendrik Schon (Bell Labs) submitted and passed peer review 15 papers published in Science and
Nature (1998-2001) found to be fraudulent.
– Igor and Grichka Bogdanov 1999 & 2002 published papers in theoretical physics believed by many to
be jargon-rich nonsense.
• Famous papers that got rejected that later turned out to be seminal works:
– Krebs & Johnson’s 1937 paper on the role of citric acid on metabolism was rejected by Nature as being
of “insufficient importance”, was eventually published in the Dutch journal Enzymologia. This
discovery, now known as the Krebs Cycle, was recognized with a Nobel prize in 1953.
– Black & Scholes 1973 paper on “the pricing of options and corporate liabilities”, rejected many times,
was eventually published at the intersession of Merton Miller to get it accepted by the Journal of Political
Economy. This work led to the Nobel Prize.
Credit: Peggy Dominy & Jay Bhatt
Does it Work? The Issue In a Nutshell
• “Stand at the top of the stairs with a pile of papers and throw them
down the stairs. Those that reach the bottom are published.”
=> It is not clear to what extent peer review improves the submitted product
• “Sort the papers into two piles: those to be published and those to
be rejected. Then swap them over!”
=> Peer review is often haphazard and unmonitored
Adapted from Trish Groves: BMJ What Do We Know About Peer Review
Typical Journal Statistics (eg BMJ)
• 6000-7000 research papers received
• About 5-7% accepted
• 1000 rejected by one editor within 48 hours
– further 3000 rejected with second editor
– within one week of submission 3000 read by senior editor;
further 1500 rejected
– 1500 sent to two reviewers; then 500 more rejected
– 500 reach weekly manuscript meeting (with Editor, a clinicians
and a statistician)
– 350 research articles accepted, usually after revision
• See Over for Detailed Figure
BMJ Manuscript Processing
1000 Hand written
Immediately Silly mistakes
per year rejected Wrong journal
2500 Poorly written
5000 scanned by 1
Rejected by Obvious flaws
editor Too Obscure
2500 sent 1000 Rejected Methodological
for review by reviewer / concerns
editor Not interesting
500 discussed 400 rejected 100 accepted
1500 sent to 500 discussed 400 rejected 100 accepted
500 discussed 400 rejected 100 accepted
Acceptance Rate 300 accepted per year
= 1 in 20 (6 per week + 2 short
Functions/Responsibilities of Peer Review
1. Filtering out incorrect, inadequate & fraudulent work
2. Improving the accuracy and clarity of work that warrants
3. Helping journals deal with high volumes
4. Helping journals deal with multiple publication
These Are NOT Functions of Peer Review
• Deciding whether the paper should be accepted
– This is the role of the editor
• Improving the spelling and grammar
– This is the role of the copy-editor
• Improving on the study design
– This is the role of the author
• Deciding upon the author order
– This is the role of the authors
• Disseminating the reviewed paper
– This is not allowed unless the paper is officially in print
Practicalities of Peer Review
Filters, Publication Cycle, Responsibilities, Tips
Overview of Peer Review
Author Filter Editorial Filter Peer Review Filter Outcome
Score (1-10) Grade
Grading Accept Published
Where to Article
Submit Appraisal Revise Article
Reject to Author
Credit: Bradley Hemminger Qualitative
Questions before starting to Review
– Do I have expertise in the content or methods, or a valuable perspective on
• Potential conflicts :
– Do I have conflicts of interest that preclude fair and balanced judgments?
– Do I stand to gain, either financially or personally, from reviewing this
– Will I be able to hold the main information that I gain from reviewing this
manuscript confidential until publication?
• Ability to meet deadline
– Do I have the time to devote to this review and complete it by the date the
Peer Review: Integral to Science and Indispensable to Annals 1038 16 December 2003 Annals of Internal Medicine Volume 139 • Number 12
Questions whilst completing the Review
• Does the review address the relevance of the topic to readers?
• Does the review address the manuscript’s importance and novelty and say what
it adds to existing knowledge?
• Does the review address the validity of the research, pointing out major strengths
and weaknesses of the methods?
• Does the review address the clarity of presentation?
• Does the review address important missing and/or inaccurate
• Does the review address the generalizability of findings?
• Does the review address the interpretation of results and stated conclusions?
• Does the review address whether the authors noted and discussed important
• Does the review cite specifics to support criticisms?
• Does the review offer suggestions for improvement?
• Does the review keep nitpicking to a minimum?
• Is the review’s tone balanced?
• Did I declare potential conflicts of interest?
Peer Review: Integral to Science and Indispensable to Annals 1038 16 December 2003 Annals of Internal Medicine Volume 139 • Number 12
• What Happens When Referees Disagree:
– (a) the Editor must decide
– (b) Option to Use more additional reviews as a tie-breaker
– (c) invite authors to reply to a referee's criticisms
– (d) an editor may convey communications back and forth
between authors and a referee
– Usually however the editor will reject the paper if there is 1x
negative review unless there is a special reason not to do so.
This process is not open, and such decisions are often
unexplained to authors
Tips for Reviewers: 1
• Be courteous and constructive
• Your role is advising not deciding
• Try to suggest improvement no matter what the outcome
• Maintain confidentiality
• Don’t review work for those you know well
• Complete reviews promptly, typically within 4 weeks
• Spend at least 1 hour on the review
• Search for related (esp recent work)
• Write as you would like to be written to
Tips for Reviewers 2 - Key Questions
• Is the research question Appropriate?
• Was the question answered?
• Were the methods appropriate?
• What must be improved?
• What could be improved?
• What were the strengths?
• Was all relevant literature considered?
• What will readers think
• => Would I object if my review was published
Rules of the Game are Not Explicit
Peters and Ceci (1982)
Resubmitted 12 altered articles to psychology journals that
had already published them but changed
title/abstract/introduction/authors’ name/name of
• 3 articles recognised as resubmissions
• One accepted
• 8 rejected on methdological grounds!
Peters, D.C., & Ceci, S.J. (1982). Peer review practices of psychological journals: The fate of published articles, submitted again. The
Behavioral and Brain Sciences, 5, 187-255.
What’s Wrong with Peer Review?
• For Authors, Peer review:
– Usually Unreliable (Idiosyncratic)
– Often Unfair (many biases)
– Has no gold standard (Unstandarized)
– Often provides qualitative comments only
• For Journals, Peer review:
– Stifles innovation => encourages group think
– Rewards the prominent
– Causes unnecessary delay in publication
– Is very expensive
– Does not detect fraud, duplicate publication etc
Juan Miguel Campanario, quot;Rejecting Nobel class articles and resisting Nobel class discoveriesquot;, cited in Nature, 16 October 2003, Vol 425, Issue 6959, p.645
Sophie Petit-Zeman, quot;Trial by peers comes up shortquot; (2003) The Guardian, Thursday January 16, 2003
Inter-Rater Reliability Issues - 1
• Locke reported inter-observer values ranging from 0.11 to 0.49 for agreement
between a number of reviewers making recommendations on a consecutive
series of manuscripts submitted to BMJ
• Ingelfinger reported Rates of agreement only “moderately better than chance”
(Kappa = 0.26) with agreement greater for rejection than acceptance
• Strayhorn and colleagues reported a value of 0.12 (poor agreement) for 268
manuscripts submitted to the JAACAP (Strayhorn et al., 1993)
• low levels of agreement were reported by Scharschmidt et al. for papers
submitted to the Journal of Clinical Investigation (Scharschmidt et al., 1994
Two reviewers are not enough
• Fletcher and Fletcher 1999 - need at least six reviewers, all favouring rejection or
acceptance, to yield a stats significant conclusion (p<0.05)
Ingelfinger FJ. Peer review in biomedical publication. American Journal of Medicine 1974; 56:686-692..
Locke S. A difficult balance: editorial peer review in medicine. London: Nuffield Provincial Hospitals Trust; 1985.
Strayhorn J Jr, McDermott JF Jr, Tanguay P. An intervention to improve the reliability of manuscript reviews for the Journal of the American
Academy of Child and Adolescent Psychiatry. Am J Psychiatry 1993; 150: 947–52.
Scharschmidt BF, DeAmicis A, Bacchetti P, Held MJ. Chance, concurrence and clustering: analysis of reviewers' recommendations on 1000
submissions to the Journal of Clinical Investigation. J Clin Invest 1994; 93: 1877–80.
Inter-Rater Reliability Issues - 2
• Linkov F et al Quality Control of Epidemiological Lectures Online:
Scientific Evaluation of Peer Review Croat Med J. 2007;48:249-55
Is agreement between reviewers any greater than would be
expected by chance alone?
• We studied two journals in which
manuscripts were routinely assessed
by two reviewers, and two
conferences in which abstracts were
routinely scored by multiple
• Agreement between the reviewers as
to whether manuscripts should be
accepted, revised or rejected was not
significantly greater than that
expected by chance.
• Editors were very much more likely to publish papers when both reviewers
recommended acceptance than when they disagreed or recommended rejection
• There was little or no agreement between the reviewers as to the priority
Rothwell PM & Martyn CN Reproducibility of peer review in clinical neuroscience Is agreement between reviewers any
greater than would be expected by chance alone? Brain, Vol. 123, No. 9, 1964-1969, 2000
Reliability of Editors' Subjective Quality Ratings of Peer Reviews
• Objective.— Whether editors' quality ratings of peer reviewers are reliable and how they
compare with other performance measures.
• Design.— A 3.5-year prospective observational study.
• Participants.— All editors and peer reviewers who reviewed at least 3 manuscripts.
• Main Outcome Measures.— Reviewer quality ratings, individual reviewer rate of
recommendation for acceptance, congruence between reviewer recommendation and
editorial decision (decision congruence), and accuracy in reporting flaws in a masked test
• Interventions.— Editors rated the quality of each review on a subjective 1 to 5 scale.
• Results.— A total of 4161 reviews of 973 manuscripts by 395 reviewers were studied.
The within-reviewer intraclass correlation was 0.44 (P<.001), indicating that 20% of the
variance seen in the review ratings was attributable to the reviewer. Intraclass correlations
for editor and manuscript were only 0.24 and 0.12, respectively. Reviewer average quality
ratings correlated poorly with the rate of recommendation for acceptance (R=-0.34) and
congruence with editorial decision (R=0.26). Highly rated reviewers reported twice as
many flaws as poorly rated reviewers.
• Conclusions.— Subjective editor ratings of individual reviewers were moderately
reliable and correlated with reviewer ability to report manuscript flaws.
Callaham ML et al Reliability of Editors' Subjective Quality Ratings of Peer Reviews of
Manuscripts JAMA. 1998;280:229-231.
• Prestige (author/institution)
• Where they live and work
• Positive results
• English language
Bias from Hidden Reviewers
Unknown + -
See Maddox J. Conflicts of interest declared [news]. Nature 1992; 360: 205;
Locke S. Fraud in medicine [editorial]. Br Med J 1988; 296: 376–7.
Open & Blind Review & Submission
• Does revealing reviewers’ identity influence outcome?
– Open vs blind peer review
• Does revealing Authors’ identity influence outcome?
– Open vs blind submission
• Key Studies
“Effect of Blinding and Unmasking on the Quality of
Peer Review A Randomized Trial JAMA” vs Blind Submission
Design and Setting.— Randomized trial of 527 consecutive manuscripts submitted
to BMJ, which were randomized and each sent to 2 peer reviewers.
• Interventions.— Manuscripts were randomized as to whether the reviewers
were unmasked, masked, or uninformed that a study was taking place. Two
reviewers for each manuscript were randomized to receive either a blinded or an
• Results.— Of the 527 manuscripts entered into the study, 467 (89%) were
successfully randomized and followed up. The mean total quality score was 2.87.
There was little or no difference in review quality between the masked and
unmasked groups (scores of 2.82 and 2.96, respectively) and between the blinded
and unblinded groups (scores of 2.87 and 2.90, respectively). There was no
apparent Hawthorne effect. There was also no significant difference between
groups in the recommendations regarding publication or time taken to review.
• Conclusions.— Blinding and unmasking made no editorially significant
difference to review quality, reviewers' recommendations, or time taken to
Van Rooyen et al Effect of Blinding and Unmasking on the Quality of Peer Review A Randomized Trial
“Effect on the quality of peer review of blinding peer
reviewers and asking them to sign their reports”
Open vs Blind Submission
• Objective.— To evaluate the effect on the quality of peer review of blinding reviewers to the
authors' identities and requiring reviewers to sign their reports.
• Design.— Randomized controlled trial.
• Setting.— A general medical journal.
• Participants.— A total of 420 reviewers from the journal's database.
• Intervention.— We modified a paper accepted for publication introducing 8 areas of weakness.
Reviewers were randomly allocated to 5 groups. Groups 1 and 2 received manuscripts from which
the authors' names and affiliations had been removed, while groups 3 and 4 were aware of the
authors' identities. Groups 1 and 3 were asked to sign their reports, while groups 2 and 4 were asked
to return their reports unsigned. The fifth group was sent the paper in the usual manner of the
journal, with authors' identities revealed and a request to comment anonymously. Group 5 differed
from group 4 only in that its members were unaware that they were taking part in a study.
• Main Outcome Measure.— The number of weaknesses in the paper that were commented on by the
• Results.— Reports were received from 221 reviewers (53%). The mean number of weaknesses
commented on was 2 (1.7, 2.1, 1.8, and 1.9 for groups 1, 2, 3, and 4 and 5 combined, respectively).
There were no statistically significant differences between groups in their performance. Reviewers
who were blinded to authors' identities were less likely to recommend rejection than those who were
aware of the authors' identities (odds ratio, 0.5; 95% confidence interval, 0.3-1.0).
• Conclusions.— Neither blinding reviewers to the authors and origin of the paper nor requiring them
to sign their reports had any effect on rate of detection of errors. Such measures are unlikely to
improve the quality of peer review reports
Godlee et al JAMA. 1998;280:237-240.
“The effects of blinding on the quality of peer review. A
randomized trial” Open vs Blind Submission
• Peer reviewers are blinded sometimes to authors' and institutions' names, but the
effects of blinding on review quality are not known.
• We, therefore, conducted a randomized trial of blinded peer review. Each of 127
consecutive manuscripts of original research that were submitted to the Journal
of General Internal Medicine were sent to two external reviewers, one of whom
was randomly selected to receive a manuscript with the authors' and institutions'
• Reviewers were asked, but not required, to sign their reviews.
• Blinding was successful for 73% of reviewers.
• Quality of reviews was higher for the blinded manuscripts (3.5 vs 3.1 on a 5-
point scale). Forty-three percent of reviewers signed their reviews, and blinding
did not affect the proportion who signed. There was no association between
signing and quality. Our study shows that, in our setting, blinding improves the
quality of reviews and that research on the effects of peer review is possible.
McNutt et al JAMA Vol. 263 No. 10, March 9, 1990
“Does Masking Author Identity Improve Peer Review
Quality? A Randomized Controlled Trial” Open vs Blind Submission
• Objectives.— To determine whether masking reviewers to author identity is generally associated
with higher quality of review at biomedical journals, and to determine the success of routine
• Interventions.— Two peers reviewed each manuscript. In one study arm, both peer reviewers
received the manuscript according to usual masking practice. In the other arm, one reviewer was
randomized to receive a manuscript with author identity masked, and the other reviewer received an
• Main Outcome Measure.— Review quality on a 5-point Likert scale as judged by manuscript
author and editor. A difference of 0.5 or greater was considered important.
• Results.— A total of 118 manuscripts were randomized, 26 to usual practice and 92 to intervention.
In the intervention arm, editor quality assessment was complete for 77 (84%) of 92 manuscripts.
Author quality assessment was complete on 40 (54%) of 74 manuscripts. Authors and editors
perceived no significant difference in quality between masked (mean difference, 0.1; 95%
confidence interval [CI], -0.2 to 0.4) and unmasked (mean difference, -0.1; 95% CI, -0.5 to 0.4)
reviews. We also found no difference in the degree to which the review influenced the editorial
decision (mean difference, -0.1; 95% CI,-0.3 to 0.3). Masking was often unsuccessful (overall, 68%
successfully masked; 95% CI, 58%-77%), although 1 journal had significantly better masking
success than others (90% successfully masked; 95% CI, 73%-98%). Manuscripts by generally
known authors were less likely to be successfully masked (odds ratio, 0.3; 95% CI, 0.1-0.8). When
analysis was restricted to manuscripts that were successfully masked, review quality as assessed by
editors and authors still did not differ.
• Conclusions.— Masking reviewers to author identity as commonly practiced does not improve
quality of reviews. Since manuscripts of well-known authors are more difficult to mask, and those
manuscripts may be more likely to benefit from masking, the inability to mask reviewers to the
identity of well-known authors may have contributed to the lack of effect.
Justice et al. JAMA. 1998;280:240-242.
“Differences in Review Quality and Recommendations for
Publication Between Peer Reviewers Suggested by Authors/Editorsquot;
Choice vs No-Choice Reviewer
• Design, Setting, and Participants Observational study of original research papers sent
for external review at 10 biomedical journals. Editors were instructed to make decisions
about their choice of reviewers in their usual manner. Journal administrators then
requested additional reviews from the author's list of suggestions according to a strict
• Main Outcome Measure Review quality using the Review Quality Instrument and the
proportion of reviewers recommending acceptance (including minor revision), revision,
• Results There were 788 reviews for 329 manuscripts. Review quality (mean difference
in Review Quality Instrument score, –0.05; P = .27) did not differ significantly between
author- and editor-suggested reviewers. The author-suggested reviewers were more likely
to recommend acceptance (odds ratio, output95% confidence interval, 1.02-2.66) or revise
Gutenburg publishing, increasing 1.64;
(odds ratio, 2.66; 95% confidence interval, 1.43-4.97). This difference was larger in the
open reviews of BMJ than among the blinded reviews of other journals for acceptance
(P = .02). Where author- and editor-suggested reviewers differed in their
recommendations, the final editorial decision to accept or reject a study was evenly
balanced (50.9% of decisions consistent with the preferences of the author-suggested
• Conclusions Author- and editor-suggested reviewers did not differ in the quality of their
reviews, but author-suggested reviewers tended to make more favorable
recommendations for publication.
Schroter JAMA 2006;295:314-317; see also Scharschmidt et al J Clin Invest 1994; 93: 1877–80.
• Deliberately inserted 8 errors(method, analysis and
interpretation) into an accepted paper
• sent it to 400 reviewers - 221 responded
• mean number of weaknesses found was 2
• only 10% identified 4 or more
• 16% didn’t detect any •Godlee,F et al JAMA,1998,280,237
“Open peer review: a randomised controlled trial”
Br Journal Psychiatry 2000
• 408 manuscripts assigned to
reviewers who agreed were
randomised to signed or unsigned
• 245 reviewers (76%) agreed to
sign their name.
• Signed reviews were of 5%
higher quality, more courteous
and took longer to complete than
• They were more likely to
Walsh et al (2000) Br Journal Psychiatry 176(1)47-51
van Rooyen BMJ 1999;318:23-27
• 125 eligible papers were sent to two reviewers who were
randomised to have their identity revealed to the authors or
to remain anonymous.
• Identified were 12% more likely than anonymous (35% v
23%) to decline to review the paper.
• There was no significant difference in quality
• No significant difference in the recommendation regarding
publication or time taken to review the paper.
Problems: Plagarism & Duplicates
• A poll of 3,247 scientists funded by the U.S.
National Institutes of Health found 0.3% admitted
faking data, 1.4% admitted plagiarism, and 4.7%
admitted to autoplagiarism (republishing).[Weiss]
• Note: Reviewers generally lack access to full raw
• Weiss, Rick. 2005. Many scientists admit to misconduct: Degrees of deception vary in poll.
Washington Post. June 9, 2005. page A03.
Evidence behind Peer Review
What does the evidence suggest….who judges the judges?
“Effects of Editorial Peer Review: A Systematic
• 9 studies considered the effects of concealing reviewer/author identity.
– 4 studies suggested that concealing reviewer or author identity affected review quality
(mostly positively); however, methodological limitations make their findings
• One study suggested that a statistical checklist can improve report quality, but
another failed to find an effect of publishing another checklist.
• 2 studies of how journals communicate with reviewers did
not demonstrate any effect on review quality.
• 1 study failed to show reviewer bias.
• 1 nonrandomized study compared the quality of articles
published in peer-reviewed vs other journals
• Two studies showed that editorial processes make articles
more readable and improve the quality of reporting
Jefferson T et al JAMA. 2002;287:2784-2786
Future of Peer Review
Open publication, training, what makes a good reviewer?
Open Publication Cycle – 12 months
T0 T+1mo T+3mo T+5mo
Step1 Step 2 Step 3 Step 4
Paper Present to Present at Submit to
Completed colleagues conference online journal
T+6mo T+7mo T+9mo
Step 5 Step 6 Public Step 8
Editor Publishes Revision
Step 7 Peer
Step 9 Step 10 Step 11
Online proof Open Access Publication Readers letters
New Models: Case 1
• All submitted articles within scope are immediately posted on the
Web for a 90 day discussion period
• At end of “review” period, authors given option to revise; revised
article sent out for “pass-fail” review”
• If “pass,” article is published
New Models: Case 2
• Authors select reviewers from among BD editorial board members
• Reviews published alongside author’s responses as part of article
• Three reviews required
New Models: Case 3
• Pre-publication review focuses
on technical rather than
• All published papers made
available for community-
based open peer review
including online annotation,
discussion, and rating
• Managing Editor, Chris
Open Access Publishing
Discussion Forum (Pub. Stage 1) + Journal (Pub. Stage 2)
Effects of training on quality of peer review:
randomised controlled trial
• Reviewers in the self taught group scored higher in review quality
after training than did the control group, but the difference was not
of editorial significance and was not maintained in the long term.
– Both intervention groups identified significantly more major errors after
training than did the control group (3.14 and 2.96 v 2.13; P < 0.001), and this
remained significant after the reviewers' performance at baseline assessment
was taken into account.
– The evidence for benefit of training was no longer apparent on further testing
six months after the interventions. Training increased likelihood of
recommending rejection (92% and 84% v 76%; P = 0.002).
• Short training packages have only a slight impact on the quality of
Schroter et al BMJ 2004;328:673
What errors do peer reviewers detect, and does training
improve their ability to detect them?
• Design 607 peer reviewers at the BMJ were randomized to two intervention
groups receiving different types of training (face-to-face training or a self-taught
package) and a control group. Each reviewer was sent the same three test papers
over the study period, each of which had nine major and five minor
methodological errors inserted.
• Main outcome measures The quality of review, assessed using a validated
instrument, and the number and type of errors detected before and after training.
• Results The number of major errors detected varied over the three papers. The
interventions had small effects. At baseline (Paper 1) reviewers found an average
of 2.58 of the nine major errors, with no notable difference between the groups.
The mean number of errors reported was similar for the second and third papers,
2.71 and 3.0, respectively. Biased randomization was the error detected most
frequently in all three papers, with over 60% of reviewers rejecting the papers
identifying this error. Reviewers who did not reject the papers found fewer errors
and the proportion finding biased randomization was less than 40% for each
• Conclusions Editors should not assume that reviewers will detect most major
errors, particularly those concerned with the context of study. Short training
packages have only a slight impact on improving error detection
J R Soc Med 2008;101:507-514
What Makes a Good Reviewer?
• A reviewer was less than 40 years old
• From a top academic institution
• Well known to the editor choosing the reviewer
• Author blinded to the identity of the manuscript's authors
• Then the probability of good review was 87% vs 7%
Evans AT, McNutt RA, Fletcher SW, Fletcher RH. The characteristics of peer reviewers who produce good-quality
reviews. J Gen Intern Med. 1993 Aug;8(8):422-8
Why Credit for Reviewing?
• Leanne Tite, Sara Schroter Why do peer reviewers decline to review? A
survey Journal of Epidemiology and Community Health 2007;61:9-12;
Richard Horton (editor The Lancet):
• quot;The mistake, of course, is to have thought that peer
review was any more than a crude means of discovering
the acceptability — not the validity — of a new finding.
Editors and scientists alike insist on the pivotal
importance of peer review. We portray peer review to the
public as a quasi-sacred process that helps to make
science our most objective truth teller. But we know that
the system of peer review is biased, unjust,
unaccountable, incomplete, easily fixed, often insulting,
usually ignorant, occasionally foolish, and frequently
eMJA: Horton, Genetically modified food: consternation, confusion, and crack-up
Overview of Changes
Peer Identity Author (Draft) Paper in print
Past Hidden Declared Declared
Current Partially Partial Anony. Declared
Future Declared Anonymous Declared
10 Suggestions for Better Peer Review
1. Make Peer Review part of training (with supervision)
2. Disclose the identifies of the reviewers
3. Hide the identities of the authors
4. Peer review with a minimum of 3 reviewers
5. Have a quantitative and qualitative element
6. Allow anyone to comment whilst the article is “online only”
7. Score every peer review and avoid use of low scorers
8. Require reviewers to disclose absence of bias & require authors to
submit full datasets
9. Show the authors the full review on request
10. Publish the peer reviews for every paper (accepted or rejected)
• Smith Peer review: a flawed process at the heart of science and journals.
• Linkov et al. Scientific Journals are 'faith based': is there science behind Peer review? JRSM 2006;99:596-598.
• Schroter et al. What errors do peer reviewers detect, and does training improve their ability to detect them?
• Rennie R. Editorial peer review:its development and rationale
• In Godlee F, Jefferson T, editors. Peer review in health sciences. Second edition. London: BMJ
• Overbeke J, Wager E. The state of evidence: what we know and what we don't know about
journal peer review In Godlee F, Jefferson T, editors. Peer review in health sciences. Second
edition. London: BMJ Books, 2003:45-61.
• Fletcher RH, Fletcher SW. The effectiveness of editorial peer review In Godlee F, Jefferson T,
editors. Peer review in health sciences. Second edition. London: BMJ Books, 2003:62-75.
• Martyn C. Peer review: some questions from Socrates In Godlee F, Jefferson T, editors. Peer
review in health sciences. Second edition. London: BMJ Books, 2003:322-8.
• Smith R. The future of peer review In Godlee F, Jefferson T, editors. Peer review in health
sciences. Second edition. London: BMJ Books, 2003:329-46.
• Checklist for critical appraisal
Credit: Panayiota Polydoratou and Martin Moyle
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