The effect of online status on the impact factors of general internal medicine journals.
BACKGROUND
We sought to determine the effects of becoming available online on impact factors of general medicine journals.


METHODS
Through MEDLI NE with an institutional subscription, the 2004 online status of "Medicine, General and Internal" journals listed in the Institute for Scientific Information (ISI ) Journal Citation Reports (JCR) was classified as full text on the Net (FU TON), abstract only, or no abstract available (NAA)/unavailable in MEDLI NE. Similarly, through use of a home computer without an institutional subscription, the 2004 online status of the same journals was determined. For each journal, impact factors for 1992 to 2003 were obtained.


RESULTS
Of the 102 "Medicine, General and Internal" journals listed in the ISI JCR, 71 (70%) existed in both pre-Internet (1992) and Internet (2003) eras. Of these 71 journals, those available as FU TON in 2004 had higher median impact factors than non-FU TON journals in 1992 (p < 0.0001> and 2003 (p < 0.0001). Journals that became available online, at least partially, had significant increases in median impact factors from 1992 to 2003 (p< 0.0001 for journals that became available as FUTON and for journals that provided an abstract only. However, journals that became available as FUTON had a greater increase in median impact from 1992 to 2003 than other journals (p = 0.002). Similar results were obtained using impact factor data according to journal online status through use of a home computer without an institutional subscription and for English-language journals only.


CONCLUSIONS
Becoming available online as FUTON is associated with a significant increase in journal impact factor.
Mueller
P S
PS
Division of General Internal Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA.
Murali
N S
NS
Cha
S S
SS
Erwin
P J
PJ
Ghosh
A K
AK
D015706:Bibliometrics; D016206:Databases, Bibliographic; D006801:Humans; D007388:Internal Medicine; D020407:Internet / Q000706:statistics & numerical data*; D009862:Online Systems; D010506:Periodicals as Topic / Q000706:statistics & numerical data*; D011643:Publishing / Q000639:trends*; D012189:Retrospective Studies