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(16) 1 Feb 2009

The Impact of the Impact Factor

There are several defining moments in the life of a medical journal: the inaugural issue, appointment of a new editor, and achieving MEDLINE indexing through the National Library of Medicine. There other important but less well understood milestones: coverage in Current Contents, the Science Citation Index, and in Journal Citation Reports. Why is a journals coverage in these works so important? These steps are necessary to allow the determination of a journals annual impact factor.

I have the good fortune of personally knowing Dr. Eugene Garfield, the creative genius behind the development and implementation of the journal impact factor 40 years ago. Dr. Garfield is Founder & Chairman Emeritus of the Institute for Scientific Information (ISI), now Thomson Reuters, the organization responsible for publishing the impact factors. Dr. Garfield and I have engaged in many discussions over the years concerning the scientific and medical literature and how published findings are evaluated and disseminated in the current print and electronic publishing environment. I have gained much insight into the complexities of the publishing world through these conversations and have developed an appreciation of the process and significance of the impact factor in the world of academic medicine.

The Journal Impact Factor is based on the annual Journal Citation Report (JCR) prepared by Thomson Reuters. The main purpose of the JCR is to provide quantitative data for evaluating journals. The impact factor (IF) is one of several indicators of the influence of a journal and its ranking within its specialty. The IF is a measure of the frequency with which the “average substantive article” (meaning review articles, original contributions) in a journal is cited over a given period of time. The methodology allows comparison of journals regardless of size. The current IF for a given journal is calculated based on citations to articles published in a recent two-year period. The IF for a given year is actually published the following year as it cannot be calculated until all issues for that year have been published. As an example, a journal’s 2008 IF is calculated as follows:

A = the number of times articles published in 2006-7 were cited in journals indexed in the Science Citation Index during 2008. This index includes all of the leading journals covered in MEDLINE.

B = the total number of articles published in the journal in 2006-7

A/B = 2008 journal impact factor

There are many applications of the journal impact factor and citation analysis. These include market research for publishers and advertisers but are especially crucial for the management of library journal collections. For those in the academic world, the greatest impact of the impact factor is its use as a gross indicator or approximation of the prestige (or should I say “impact”) of the journals an author has published in. While other considerations are important in assessing the quality of a journal such as peer review, productivity, rapidity of publication, and subject specialty citation rates, the IF is a defined, generally accepted and surprisingly reproducible quantitative value. Some universities use the IF to assess the suitability of a candidate’s academic qualifications for appointment and promotion.

The CJU was inaugurated in 1994 and the first Editor-in-Chief was Dr. Laurence Klotz. In 2000, the journal was selected for MEDLINE coverage with all articles from the first issue retroactively indexed in MEDLINE. Under the guidance of the CJU’s current Editor-in-Chief, Dr. Gabriel Haas, the journal’s quality, citation rate, North American and International reach has expanded dramatically. Now, the important journey towards calculating our impact factor will truly elevate the CJU to international standards among leading publications.

In 2008, the CJU began the formal process of being assigned an impact factor. Later that year, the CJU was notified by the Current Contents/Clinical Medicine editorial staff that it was accepted for coverage, the key first step in the process that generates data for the Journal Citation Report. Listing in Current Contents/Clinical Medicine means our journal is now fully indexed in the online Web of Science, the electronic version of the Science Citation Index. This is a distinction extended to only the best quality urology and other journals worldwide. Based on the procedures outlined, we anticipate the first annual impact factor in 2010.

The publisher and the Editorial Board of The Canadian Journal of Urology are honored to be included in this select group of publications. We look forward to the effects of being included in this important evaluation process through the Journal Citation Report and seeing our impact factor grow over the coming years.

Leonard G. Gomella, MD Philadelphia, Pennsylvania, USA Associate Editor


© The Canadian Journal of Urology™; 16(1); February 2009