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Fact Sheet
Errata, Retraction, Duplicate Publication and Comment Policy for MEDLINE®


The National Library of Medicine (NLM) has a long-standing tradition of providing access to information in the biomedical literature through quality programs and services. One of the ways NLM assists users is to add subsequent notices of errata, retractions, republications, duplicate publications, and comments (including updates) to citations of articles indexed and available in the Library's online MEDLINE database. Users who search MEDLINE will be informed if they retrieve a citation for an article that has subsequently been retracted, an article that has been found to duplicate another article, an article in which a substantive error has been noted, an article that has been corrected and republished, or an article that has been discussed specifically in another article, including an update of the original article. NLM links the existing citations to subsequently published errata, retraction notices, comments, and similar announcements.

Through a combination of additions to MEDLINE citations, NLM attempts to draw the user's attention to changes in an article's status, to the official notification of such a change, or to published comments concerning the article. These added elements may consist of an additional field and/or a Publication Type (PT).

Errata

Published changes or emendations to earlier articles, frequently referred to as corrections or corrigenda, are considered by NLM to be errata, regardless of the nature or origin of the error. That is, NLM does not differentiate between errors that originated in the publication process and errors of logic or methodology, because journal editors do not make this distinction consistently or clearly. Since 1987, when a publisher, editor, or author has published a labeled, citable erratum to an article that was cited in the MEDLINE database, NLM has amended the citation of the article with a bibliographic reference to the erratum notice, in order to alert users and refer them to the source of the revised information.

The reference to a published erratum notice is in the form of a notification that appears above the article title in the Abstract or Citation formats of PubMed®. In the MEDLINE format, this information appears in the EIN (Erratum in) field. Although errors may occur in any part of the published article, NLM will add the corrected information to the citation if the erroneous data were incorporated in the original MEDLINE citation. That is, if the error occurred in the article's authorship, title, or abstract, NLM will retain the original citation, if it affects retrieval, but will add the revised data to provide the correct information. If an author's name was misspelled, the corrected name is inserted in the appropriate order and the original misspelling is moved to the end of the author list. Thus, a user who wishes to follow up on all of the authors from the journal issue will be able to retrieve on the misspelled name as well. The notice about the correction will show both the incorrect spelling of the name and the corrected form.

If, however, the error occurred in a portion of the article that is not included in the MEDLINE citation, such as the text, graphs, or tables, only a reference to the published erratum notice will be added to the MEDLINE citation. Brief errata notices are not generally indexed as independent articles. Some substantive articles or letters may, however, comprise published errata. If so, these items will be indexed with the Publication Type PUBLISHED ERRATUM. For those citations having a publication date of 2002 forward, a link will refer back to the citation for the original article. That link appears above the article title in the Abstract or Citation formats of PubMed while in the MEDLINE format the information appears in the EFR (Erratum for) field.

It is NLM's policy that errata will be acknowledged only if they are printed in a citable form; that is, an erratum notice must appear on a numbered page in an issue of the journal that originally published the article. Error notices that are inserted unbound into a journal issue or "tipped" will not be considered part of the permanent bibliographic record. An erratum notice pertaining to a portion of a journal that exists in online format only must be readily discernable in the table of contents of a subsequent issue. NLM does not make changes in the database in response to letters from authors or editors, unless such letters indicate that a substantive published erratum is forthcoming.

Errata Examples

Dosage correction - Note that "[corrected]" appears twice in the fourth sentence of the abstract, immediately after the dosages that were corrected.

Int Clin Psychopharmacol 1998 Nov;13(6):263-7

Erratum in:
Int Clin Psychopharmacol 1999 Mar;14(2):138

Cardiac side-effects of two selective serotonin reuptake inhibitors in middle-aged and elderly depressed patients.

Strik JJ, Honig A, Lousberg R, Cheriex EC, Van Praag HM.

Department of Psychiatry, Maastricht University Hospital, The Netherlands.

Selective serotonin reuptake inhibitors (SSRIs) are the 'new' drugs of first choice for the treatment of depression in the older patient. Systematic studies on the effects of SSRIs on cardiac function are scarce, despite the high prevalence of cardiac disorders in the older depressed patient. This is a study which systematically assessed cardiac function by echocardiography in middle-aged and elderly depressed patients treated with SSRI. In a double-blind randomized trial, 20 patients were assigned to receive fluvoxamine 100 mg/day [corrected] or fluoxetine 20 mg/day [corrected] for 6 weeks. Cardiac function was assessed by left ventricle ejection fraction, aortic flow integral and early or passive/late or active mitral inflow, and electrocardiography. Neither SSRI significantly affected cardiac function. Compared with patients without a history of myocardial infarction and/or hypertension, patients with such a history showed a significant improvement in left ventricular ejection fraction. Despite our small study sample, these data indicate that both fluoxetine and fluvoxamine do not affect cardiac function adversely.

Publication Types:
Clinical Trial
Randomized Controlled Trial

PMID: 9861576 [PubMed - indexed for MEDLINE]

Author name correction

Blood Cells Mol Dis 2000 Dec;26(6):567-71

Erratum in:
Blood Cells Mol Dis 2001 Jan-Feb;27(1):351. Volach B [corrected to Wolach B]

A new exon 9 glucose-6-phosphate dehydrogenase mutation (G6PD "Rehovot") in a Jewish Ethiopian family with variable phenotypes.

Iancovici-Kidon M, Sthoeger D, Abrahamov A, Wolach B, Beutler E, Gelbart T, Barak Y, Volach B.

Department of Pediatrics, Kaplan Medical Center, Rehovot 76100, Israel.

PMID: 11112389 [PubMed - indexed for MEDLINE]

An indexed published erratum and its corresponding correction

Am J Med Genet 2000 Aug 14;93(4):342

The devil of the one letter code and the Ehlers-Danlos syndrome: corrigendum.

Steinmann B, Giunta C.

Publication Types:
Published Erratum

PMID: 10946364 [PubMed - indexed for MEDLINE]

Corresponding correction

Am J Med Genet 2000 Jan 3;90(1):72-9

Erratum in:
Am J Med Genet 2000 Aug 14;93(4):342

Compound heterozygosity for a disease-causing G1489E [correction of G1489D] and disease-modifying G530S substitution in COL5A1 of a patient with the classical type of Ehlers-Danlos syndrome: an explanation of intrafamilial variability?

Giunta C, Steinmann B.

Division of Metabolic and Molecular Diseases, Zurich University Children's Hospital, Zurich, Switzerland.

PMID: 10602121 [PubMed - indexed for MEDLINE]

Retractions

Articles may be retracted or withdrawn by their authors, academic or institutional sponsor, editor, or publisher, because of pervasive error or unsubstantiated or irreproducible data. For example, an article's conclusions may have been based upon faulty logic or computation, its data may have been obtained by accident from a contaminated cell line or through poor instrumentation, or it may have been derived from falsified or fabricated data. NLM does not differentiate between articles that are retracted because of honest error and those that are retracted because of scientific misconduct or plagiarism. If the notification in the journal is labeled as a retraction or withdrawal, NLM will index it as a retraction.

It is NLM's policy that a retraction will be indexed as a retraction only if it clearly states that the article in question is being retracted or withdrawn, and is signed by an author of the retracted paper or author's legal counsel; by the head of the department, dean, or director of the laboratory where the paper was produced; or by the journal editor. In addition, the retraction must be labeled and published in citable form; that is, the retraction must appear on a numbered page in an issue of the journal that published the retracted article.

NLM does not simply expunge the citation of a retracted article from its indexes or databases, but rather links the original to the notice of retraction, by adding a Retraction statement after the source of the retracted article on the PubMed Summary display. The bibliographic reference for the retraction notice also appears above the title in the Abstract and Citation formats in PubMed. In the MEDLINE format, it appears in the RIN (Retraction in) field. The MEDLINE record of each retracted article will be given an additional Publication Type of RETRACTED PUBLICATION (PT) as well.

NLM makes a reciprocal linkage between the retraction statement and the retracted article. That is, the retraction statement is indexed as RETRACTION OF PUBLICATION (PT). The bibliographic reference(s) for the article(s) being retracted appear above the title in the Abstract and Citations formats in PubMed. In the MEDLINE format, they appear in the ROF (Retraction of) field.

Retraction Example

Retraction of publication

N Engl J Med 2001 Jul 5;345(1):64

Retraction of:
Brugger W, Heimfeld S, Berenson RJ, Mertelsmann R, Kanz L. N Engl J Med. 1995 Aug 3;333(5):283-7.

Retraction: reconstitution of hematopoiesis after high-dose chemotherapy by autologous progenitor cells generated ex vivo.

Kanz L, Brugger W.

Publication Types:
Retraction of Publication

PMID: 11439953 [PubMed - indexed for MEDLINE]

Retracted publication

N Engl J Med 1995 Aug 3;333(5):283-7

Retraction in:
Kanz L, Brugger W. N Engl J Med. 2001 Jul 5;345(1):64.

Comment in:
N Engl J Med. 1995 Aug 3;333(5):315-6.
N Engl J Med. 1996 Jan 25;334(4):271-2.

Reconstitution of hematopoiesis after high-dose chemotherapy by autologous progenitor cells generated ex vivo.

Brugger W, Heimfeld S, Berenson RJ, Mertelsmann R, Kanz L.

Albert-Ludwigs University Medical Center, Department of Hematology/Oncology, Freiburg, Germany.

Publication Types:
Clinical Trial
Clinical Trial, Phase I
Clinical Trial, Phase II
Retracted Publication

PMID: 7541111 [PubMed - indexed for MEDLINE]

Corrected and Republished Articles

On occasion, a journal may correct or amplify an earlier article by republishing it in its entirety, generally to rectify an editorial or printing error in the original article. NLM adds a link above the title in the Abstract or Citation format of the PubMed citation of the original article, referring the user to the corrected and republished version. The replacement will be indexed with an additional Publication Type of CORRECTED AND REPUBLISHED ARTICLE (PT) and will have a link to the original source of the article. In the MEDLINE format, the correction information appears in the RPI (Corrected and republished in) field and the correction from appears in the RPF (Corrected and republished from) field.

Corrected and Republished Example

Corrected and republished

J Comp Neurol 2000 Nov 6;427(1):461-80

Corrected and republished from:
J Comp Neurol. 2000 Jun 12;421(4):461-80.

Formation of cadherin-expressing brain nuclei in diencephalic alar plate divisions.

Yoon MS, Puelles L, Redies C.

Institute of Anatomy, University Hospital Essen, Germany

Publication Types:
Corrected and Republished Article

PMID: 11183875 [PubMed - indexed for MEDLINE]

Original

J Comp Neurol 2000 Jun 12;421(4):461-80

Corrected and republished in:
J Comp Neurol. 2000 Nov 6;427(1):461-80.

Formation of cadherin-expressing brain nuclei in diencephalic alar plate divisions.

Yoon MS, Puelles L, Redies C.

Institute of Anatomy, University Hospital Essen, Germany.

PMID: 10842209 [PubMed - indexed for MEDLINE]

Duplicate Publications

NLM identifies an article that substantially duplicates another article without acknowledgment by assigning both articles the Publication Type DUPLICATE PUBLICATION (PT). In general, such articles have one or more authors in common and a substantial amount of duplicated text. Duplication may occur intentionally, to achieve wider dissemination of an article such as a policy statement, or inadvertently, through multiple submission of a manuscript to different journals.

Unlike other Publication Types described in this fact sheet, DUPLICATE PUBLICATION may be added with or without a formal notification from authors or journal editors. In the indexing process, indexers sometimes recognize duplicate or very similar publications. If inspection of the potentially duplicative articles indicates a substantial amount of overlap, the PT will be added. NLM does not, however, routinely examine articles for originality.

Duplicate Example

1

Cesk Slov Oftalmol 1999 Nov;55(6):372-6

[Use of citation indexes and impact factors]

[Article in Czech]

Pitterova K.

Knihovna AV CR, Praha.

Publication Types:
Duplicate Publication

PMID: 10677906 [PubMed - indexed for MEDLINE]

2

Cesk Patol 1999 Oct;35(4):144-6

[Use of science citation indexes and impact factors]

[Article in Czech]

Pitterova K.

Knihovna AV CR, Praha.

Publication Types:
Duplicate Publication

PMID: 10677915 [PubMed - indexed for MEDLINE]

Comments

Comments are substantive articles or letters that challenge, refute, support, or expand upon another article or letter. Among the types of articles that will be considered comments are: invited comments on an earlier article, letters to the editor that were inspired by a previous article, articles that update previous articles, and announcements or notices that serve as quasi retractions. A mere mention of one or more articles in the text or references of another article does not constitute a comment. The commenting article must, instead, have been written primarily for the purpose of making a comment - that is, of drawing the reader's attention to the referent article. Each commenting citation is indexed with the Publication Type of COMMENT. Beginning in 1989, NLM has created bibliographic linkages in MEDLINE between commenting articles and the article or articles to which they refer.

The comment linkage has two components in MEDLINE: an identifying phrase above the title of each of the pair of citations in the PubMed Abstract and Citation formats, and a data field in the PubMed MEDLINE format (abbreviated CIN for Comment in and CON for Comment on) containing the bibliographic source of either the citing or cited article. Specifically, the commenting article citation will have the CON field containing the source of the referent article while the article being commented upon will have the CIN field containing the source of the commenting article. The comments fields will be repeated to identify the location of as many comments about an article as are published.

Published comments are linked to referent articles only if they are printed in citable form; that is, on a numbered page in a journal issue. In general, NLM limits linkages to comments that were published in the same journal as the article to which they refer. Furthermore, the referent article must have been indexed for MEDLINE; that is, it must have met the scope and format requirements for selection in the first place. The commenting article is indexed independently; that is, it may or may not be indexed with the same medical subject headings as the article to which it refers, depending upon its contents. One exception to the general policy on comments concerns journals that largely contain analytical evaluations of published original studies. For such journals, comment linkages are made to other journal titles and, prior to 2002, the comment was only on the citation to the original paper (a separate citation for the analysis itself was not created).

Comment Example

Comment on article in same journal

Am J Med 2001 May;110(7):589-90

Comment on:
Am J Med. 2001 May;110(7):515-9.

The dark side of deep venous thrombosis: the failure of anticoagulation.

Horne MK 3rd.

Publication Types:
Comment
Editorial

PMID: 11343675 [PubMed - indexed for MEDLINE]

Comment in article in same journal

Am J Med 2001 May;110(7):515-9

Comment in:
Am J Med. 2001 May;110(7):589-90.

Does the location of thrombosis determine the risk of disease recurrence in patients with proximal deep vein thrombosis?

Douketis JD, Crowther MA, Foster GA, Ginsberg JS.

Department of Medicine, McMaster University, Hamilton, Ontario, Canada.jdouket@fhs.mcmaster.ca

PMID: 11343664 [PubMed - indexed for MEDLINE]

Comment in article to another journal

Ann Intern Med 1999 Jun 15;130(12):963-70

Comment in:
ACP J Club. 1999 Nov-Dec;131(3):77

Relation of consumption of vitamin E, vitamin C, and carotenoids to risk for stroke among men in the United States.

Ascherio A, Rimm EB, Hernan MA, Giovannucci E, Kawachi I, Stampfer MJ, Willett WC.

Department of Nutrition, Harvard School of Public Health, Boston, Massachusetts 02115, USA. alberto.ascherio@channing.harvard.edu

PMID: 10383366 [PubMed - indexed for MEDLINE]

Author Responses to Comments

Frequently, the author of an article being commented upon has been invited to supply a response to the comment. Such author responses are not indexed as separate items; instead, the comment is cited with pagination that includes the reply often indicated as "discussion." The link to the original citation provides an appropriate reference for the author of the original item. Although such replies are not indexed separately for MEDLINE, any substantive discussion provided in the response is considered when subject headings are assigned to the commenting citation.

Author Response to Comment Example

NLM includes an author's response to a comment as part of the pagination of the comment citation as seen in this PubMed Summary format:

Copur MS, Ledakis P, Bolton M, Norvell M, Muhvic J.
Is anastrozole superior to tamoxifen as first-line therapy for advanced breast cancer?
J Clin Oncol. 2001 May 1;19(9):2578; discussion 2580-2. No abstract available.
PMID: 11331343 [PubMed - indexed for MEDLINE]

Authors who prefer to cite their replies as a separate item may add the note "Included with PubMed PMID #######." after the bibliographic citation to their response. Authors are encouraged to follow the following format:

Nabholtz JM, Bonneterre J, Buzdar A, Robertson JF, Thurlimann B, Steinberg M, Webster A, von Euler M.
Is anastrozole superior to tamoxifen as first-line therapy for advanced breast cancer? Reply to Copur MS, et al. [letter]
J Clin Oncol. 2001 May 1;19(9):2580-2. Included with PubMed PMID 11331343.

Updated Articles

Articles that update previous articles are linked using a pair of elements called "Update of" and "Update in." This kind of updating has occurred primarily in journals that are published solely online; NLM began to distinguish the updates with articles published in 2001 forward. Like the more generic comment fields, this update commentary appears above the title of each pair of citations in the PubMed Abstract and Citation formats. In the PubMed MEDLINE format, this information appears in the UOF (Update of) or UIN (Update in) fields that signal the bibliographic source of either the updating or updated article, respectively.

Update Example

Update of

Cochrane Database Syst Rev 2000;(4):CD000337

Update of:
Cochrane Database Syst Rev. 2000;(2):CD000337.

Conservative versus operative treatment for hip fractures.

Parker MJ, Handoll HH, Bhargara A.

Orthopaedics and Trauma, Peterborough Hospital NHS Trust, Thorpe Road, Peterborough, Cambridgeshire, UK, PE3 6DA. mjparker@globalnet.co.uk

Publication Types:
Review
Review, Academic

PMID: 11034683 [PubMed - indexed for MEDLINE]

Update in

Cochrane Database Syst Rev 2000;(2):CD000337

Update in:
Cochrane Database Syst Rev. 2000;(4):CD000337.

Conservative versus operative treatment for extracapsular hip fractures.

Parker MJ, Handoll HH.
Orthopaedic Department, Peterborough District Hospital, Thorpe Road, Peterborough, Cambridgeshire, UK, PE3 6DA. mjparker@globalnet.co.uk

Publication Types:
Review
Review, Academic


PMID: 10796345 [PubMed - indexed for MEDLINE]

Index Medicus®

The errata, retraction, corrected and republished article, duplicate publication, and comment Publication Types and linkages are more likely to be applied to citations in the online database MEDLINE than in the monthly Index Medicus. If, however, the erratum, retraction, republication notice, or comment, is published and NLM makes the link before printing the monthly Index Medicus, then the amended citation will appear in Index Medicus. Citations to earlier articles which subsequently have been corrected or retracted, or which recently have been the subject of commentary are not reprinted in Index Medicus for the purpose of adding the linkage.

For further information about errata, retractions, corrected and republished articles, duplicate publications, and comments in MEDLINE, please contact:

Head, Index Section
National Library of Medicine
Bethesda, Maryland 20894
Phone: 301-496-3262
Fax: 301-402-2433
email: james_marcetich@nlm.nih.gov

A complete list of NLM Fact Sheets is available at:
Alphabetical list: http://www.nlm.nih.gov/pubs/factsheets/factsheets.html
Subject list: http://www.nlm.nih.gov/pubs/factsheets/factsubj.html

Or write to:

FACT SHEETS
Office of Communications and Public Liaison
National Library of Medicine
8600 Rockville Pike
Bethesda, Maryland 20894

Phone: (301) 496-6308
Fax: (301) 496-4450
email: publicinfo@nlm.nih.gov

Last updated: 06 March 2002
First published: 06 March 2002
Metadata| Permanence level: Permanent: Stable Content