Home CHEST Thought Leaders Impact Factor: What's in a Number?

Impact Factor: What's in a Number?

Dr. IrwinBy Richard S. Irwin, MD, Master FCCP

About the Author: Richard S. Irwin is editor in chief of CHEST.

The answer to this question, quite simply, is our reputation. The new Journal Citation Report Impact Factor (IF) numbers for 2012 were released recently, and we are pleased that CHEST's IF for 2012 has increased from 5.25 to 5.85. This puts CHEST in 4th place out of 50 journals in the Respiratory Systems category and in 3rd place out of 27 journals in the Critical Care category.

The regular impact factor is calculated by the number of citations received per paper published in the journal during the previous 2 years (eg, the impact factor for 2012 was computed by adding the citations in 2010 and 2011 and then dividing this number by the number of articles published in CHEST during 2010 and 2011). In the past, ISI (the company that publishes the impact factor and related metrics) has been criticized by some who said that the 2-year window for citations was simply an arbitrary number. In the past few years ISI has added a more meaningful “5-Year Impact Factor” measure. For the 5-Year IF, CHEST now ranks second in the Critical Care category.

And, for the Immediacy Index in both the Respiratory and Critical Care categories, CHEST moved from 4th place in 2011 to 1st place in 2012, which indicated that the material we publish is quickly cited by others. If there were a Sleep Medicine category in the Journal Citation Reports, CHEST would be the top-ranked journal, compared with the major sleep medicine journals.

CHEST Journal impact factor 

The Eigenfactor uses a similar methodology to the IF, but it removes citations related to other articles published within the same journal. The Eigenfactor for CHEST ranks us 2nd in both the Respiratory and Critical Care categories. Seeing all of the numbers in the above table gives us great satisfaction and is a source of pride. In our January editorial “Spread the Word About the Journal in 2013: From Citation Manipulation to Invalidation of Patient-Reported Outcomes Measures to Renaming the Clara Cell to New Journal Features,” we wrote about a growing trend in journal publication—excessive self-citation. This is a form of citation manipulation whereby authors are encouraged to include references that have been included solely for the purpose of increasing citations to a particular author’s or journal’s work.

Citation manipulation is recognized as its own form of scientific misconduct, and this trend must be discouraged. I have, and will continue to take a stand, against citation manipulation preferring instead to rely on solid, good research and investigative methods.

As its editorial policy, CHEST does not participate in citation manipulation. In our minds, citation manipulation constitutes as scientific misconduct (because it qualifies as misrepresentation) and should not be tolerated. We will not game the system in any manner simply to raise our score.

I take pride in the integrity of the Journal and stand behind our decision. This is why our Eigenfactor results that take into account self-citations is so exciting and provides us much cause for celebrating. We achieved our results through publishing honest, good research.

To see more about CHEST rankings, visit the About Chest Publications page on the Journal site.