Chew, M; et al Life and times of the impact factor: retrospective analysis of trends for seven medical journals (1994-2005) and their Editors' views JOURNAL OF THE ROYAL SOCIETY OF MEDICINE, 100 (3): 142-150 MAR 2007

[Eugene Garfield]

URL:http://jrsm.rsmjournals.com/cgi/reprint/100/3/142?
maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=impact+factor&searchid=1&
FIRSTINDEX=0&volume=100&issue=3&resourcetype=HWCIT

E-mail Address: mch3004 at gmail.com 

Author(s): Chew, M (Chew, Mabel); Villanueva, EV (Villanueva, Elmer V.); 
Van Der Weyden, MB (Van Der Weyden, Martin B.) 

Title: Life and times of the impact factor: retrospective analysis of 
trends for seven medical journals (1994-2005) and their Editors' views 

Source: JOURNAL OF THE ROYAL SOCIETY OF MEDICINE, 100 (3): 142-150 MAR 
2007 

Language: English 

Document Type: Article 

Keywords Plus: CITATION; QUALITY; SCIENCE 

Abstract: Objective (1) To analyse trends in the journal impact factor 
(IF) of seven general medical journals (Ann Intern Med, BMJ, CMAJ, JAMA 
Lancet, Med J Aust and N Engl J Med) over 12 years; and (2) to ascertain 
the views of these journals' past and present Editors on factors that had 
affected their journals' IFs during their tenure, including direct 
editorial policies.
Design Retrospective analysis of IF data from ISI Web of Knowledge Journal 
Citation Reports-Science Edition, 1994 to 2005, and interviews with 
Editors-in-Chief.
Setting Medical journal publishing.
Participants Ten Editors-in-Chief of the journals, except Med J Aust, who 
served between 1999 and 2004.
Main outcome measures IFs and component numerator and denominator data for 
the seven general medical journals (1994 to 2005) were collected. IFs are 
calculated using the formula: (Citations in year z to articles published 
in years x and y)/(Number of citable articles published in years x and y), 
where z is the current year and x and y are the previous two years. 
Editors' views on factors that had affected their journals' IFs were also 
obtained.
Results IFs generally rose over the 12-year period, with the N Engl J Med 
having the highest IF throughout. However, percentage rises in IF relative 
to the baseline year of 1994 were greatest for CMAJ (about 500%) and JAMA 
(260%). Numerators for most journals tended to rise over this period, 
while denominators tended to be stable or to fall, although not always in 
a linear fashion. Nine of ten eligible editors were interviewed. Possible 
reasons given for rises in citation counts included: active recruitment of 
high-impact articles by courting researchers; offering authors better 
services; boosting the journal's media profile; more careful article 
selection; and increases in article citations. Most felt that going online 
had not affected citations. Most had no deliberate policy to publish fewer 
articles (lowering the IF denominator), which was sometimes the unintended 
result of other editorial policies. The two Editors who deliberately 
published fewer articles did so as they realized IFs were important to 
authors. Concerns about the accuracy of ISI counting for the IF 
denominator prompted some to routinely check their IF data with SI. All 
Editors had mixed feelings about using IFs to evaluate journals and 
academics, and mentioned the tension between aiming to improve IFs 
and 'keeping their constituents [clinicians] happy.'
Conclusions IFs of the journals studied rose in the 12-year period due to 
rising numerators and/or falling denominators, to varying extents. Journal 
Editors perceived that this occurred for various reasons, including 
deliberate editorial practices. The vulnerability of the IF to editorial 
manipulation and Editors' dissatisfaction with it as the sole measure of 
journal quality lend weight to the need for complementary measures. 

Addresses: Univ Sydney, Discipline Gen Practice, Sydney, NSW 2006, 
Australia; Monash Univ, Dept Rural & Indigenous Hlth, Moe, Vic, Australia
 
Reprint Address: Chew, M, Univ Sydney, Discipline Gen Practice, Sydney, 
NSW 2006, Australia. 

E-mail Address: mch3004 at gmail.com 

Cited Reference Count: 30 

Times Cited: 9 

Publisher: ROYAL SOC MEDICINE PRESS LTD 

Publisher Address: 1 WIMPOLE STREET, LONDON W1G 0AE, ENGLAND 

ISSN: 0141-0768 

29-char Source Abbrev.: J ROY SOC MED 

ISO Source Abbrev.: J. R. Soc. Med. 

Source Item Page Count: 9 

Subject Category: Medicine, General & Internal 

ISI Document Delivery No.: 149BU 

BMJ UPDATES : 
J CITATION REPORTS : 

SCI INNOVATION FRAME : 
*BIOL REP LTD

FAC 1000 WHAT FAC 10 : 

*COUNC MED SCI ROY
SOC IMP APPL HLTH RE : 

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