Impact factor: a valid measure of journal quality?

J Med Libr Assoc. 2003 Jan;91(1):42-6.


Objectives: Impact factor, an index based on the frequency with which a journal's articles are cited in scientific publications, is a putative marker of journal quality. However, empiric studies on impact factor's validity as an indicator of quality are lacking. The authors assessed the validity of impact factor as a measure of quality for general medical journals by testing its association with journal quality as rated by clinical practitioners and researchers.

Methods: We surveyed physicians specializing in internal medicine in the United States, randomly sampled from the American Medical Association's Physician Masterfile (practitioner group, n = 113) and from a list of graduates from a national postdoctoral training program in clinical and health services research (research group, n = 151). Respondents rated the quality of nine general medical journals, and we assessed the correlation between these ratings and the journals' impact factors.

Results: The correlation between impact factor and physicians' ratings of journal quality was strong (r2 = 0.82, P = 0.001). The correlation was higher for the research group (r2 = 0.83, P = 0.001) than for the practitioner group (r2 = 0.62, P = 0.01).

Conclusions: Impact factor may be a reasonable indicator of quality for general medical journals.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Validation Study

MeSH terms

  • Adult
  • Bibliometrics
  • Female
  • Humans
  • Internal Medicine / statistics & numerical data
  • Library Collection Development / standards
  • Male
  • Middle Aged
  • Periodicals as Topic / classification
  • Periodicals as Topic / standards*
  • Periodicals as Topic / statistics & numerical data*
  • Physicians / statistics & numerical data
  • Random Allocation
  • Reproducibility of Results
  • Research Personnel / statistics & numerical data
  • Sex Factors
  • Social Change*
  • Surveys and Questionnaires
  • United States / epidemiology