Conflicts of interest at medical journals: the influence of industry-supported randomised trials on journal impact factors and revenue - cohort study.
BACKGROUND: transparency in reporting of conflict of interest is an increasingly important aspect of publication in medical journals. Publication of large industry-supported trials may generate many citations and journal income through reprint sales and thereby be a source of conflicts of interest f...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2010-10-01
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| Series: | PLoS Medicine |
| Online Access: | http://europepmc.org/articles/PMC2964336?pdf=render |
| _version_ | 1811269142621192192 |
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| author | Andreas Lundh Marija Barbateskovic Asbjørn Hróbjartsson Peter C Gøtzsche |
| author_facet | Andreas Lundh Marija Barbateskovic Asbjørn Hróbjartsson Peter C Gøtzsche |
| author_sort | Andreas Lundh |
| collection | DOAJ |
| description | BACKGROUND: transparency in reporting of conflict of interest is an increasingly important aspect of publication in medical journals. Publication of large industry-supported trials may generate many citations and journal income through reprint sales and thereby be a source of conflicts of interest for journals. We investigated industry-supported trials' influence on journal impact factors and revenue. METHODS AND FINDINGS: we sampled six major medical journals (Annals of Internal Medicine, Archives of Internal Medicine, BMJ, JAMA, The Lancet, and New England Journal of Medicine [NEJM]). For each journal, we identified randomised trials published in 1996-1997 and 2005-2006 using PubMed, and categorized the type of financial support. Using Web of Science, we investigated citations of industry-supported trials and the influence on journal impact factors over a ten-year period. We contacted journal editors and retrieved tax information on income from industry sources. The proportion of trials with sole industry support varied between journals, from 7% in BMJ to 32% in NEJM in 2005-2006. Industry-supported trials were more frequently cited than trials with other types of support, and omitting them from the impact factor calculation decreased journal impact factors. The decrease varied considerably between journals, with 1% for BMJ to 15% for NEJM in 2007. For the two journals disclosing data, income from the sales of reprints contributed to 3% and 41% of the total income for BMJ and The Lancet in 2005-2006. CONCLUSIONS: publication of industry-supported trials was associated with an increase in journal impact factors. Sales of reprints may provide a substantial income. We suggest that journals disclose financial information in the same way that they require them from their authors, so that readers can assess the potential effect of different types of papers on journals' revenue and impact. |
| first_indexed | 2024-04-12T21:36:48Z |
| format | Article |
| id | doaj.art-80b6bac68d864f8c85f4b012261cc15d |
| institution | Directory Open Access Journal |
| issn | 1549-1277 1549-1676 |
| language | English |
| last_indexed | 2024-04-12T21:36:48Z |
| publishDate | 2010-10-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS Medicine |
| spelling | doaj.art-80b6bac68d864f8c85f4b012261cc15d2022-12-22T03:15:53ZengPublic Library of Science (PLoS)PLoS Medicine1549-12771549-16762010-10-01710e100035410.1371/journal.pmed.1000354Conflicts of interest at medical journals: the influence of industry-supported randomised trials on journal impact factors and revenue - cohort study.Andreas LundhMarija BarbateskovicAsbjørn HróbjartssonPeter C GøtzscheBACKGROUND: transparency in reporting of conflict of interest is an increasingly important aspect of publication in medical journals. Publication of large industry-supported trials may generate many citations and journal income through reprint sales and thereby be a source of conflicts of interest for journals. We investigated industry-supported trials' influence on journal impact factors and revenue. METHODS AND FINDINGS: we sampled six major medical journals (Annals of Internal Medicine, Archives of Internal Medicine, BMJ, JAMA, The Lancet, and New England Journal of Medicine [NEJM]). For each journal, we identified randomised trials published in 1996-1997 and 2005-2006 using PubMed, and categorized the type of financial support. Using Web of Science, we investigated citations of industry-supported trials and the influence on journal impact factors over a ten-year period. We contacted journal editors and retrieved tax information on income from industry sources. The proportion of trials with sole industry support varied between journals, from 7% in BMJ to 32% in NEJM in 2005-2006. Industry-supported trials were more frequently cited than trials with other types of support, and omitting them from the impact factor calculation decreased journal impact factors. The decrease varied considerably between journals, with 1% for BMJ to 15% for NEJM in 2007. For the two journals disclosing data, income from the sales of reprints contributed to 3% and 41% of the total income for BMJ and The Lancet in 2005-2006. CONCLUSIONS: publication of industry-supported trials was associated with an increase in journal impact factors. Sales of reprints may provide a substantial income. We suggest that journals disclose financial information in the same way that they require them from their authors, so that readers can assess the potential effect of different types of papers on journals' revenue and impact.http://europepmc.org/articles/PMC2964336?pdf=render |
| spellingShingle | Andreas Lundh Marija Barbateskovic Asbjørn Hróbjartsson Peter C Gøtzsche Conflicts of interest at medical journals: the influence of industry-supported randomised trials on journal impact factors and revenue - cohort study. PLoS Medicine |
| title | Conflicts of interest at medical journals: the influence of industry-supported randomised trials on journal impact factors and revenue - cohort study. |
| title_full | Conflicts of interest at medical journals: the influence of industry-supported randomised trials on journal impact factors and revenue - cohort study. |
| title_fullStr | Conflicts of interest at medical journals: the influence of industry-supported randomised trials on journal impact factors and revenue - cohort study. |
| title_full_unstemmed | Conflicts of interest at medical journals: the influence of industry-supported randomised trials on journal impact factors and revenue - cohort study. |
| title_short | Conflicts of interest at medical journals: the influence of industry-supported randomised trials on journal impact factors and revenue - cohort study. |
| title_sort | conflicts of interest at medical journals the influence of industry supported randomised trials on journal impact factors and revenue cohort study |
| url | http://europepmc.org/articles/PMC2964336?pdf=render |
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