Comparison of the Impact Factors of the Most-Cited Cardiovascular Journals: Why a Median-Based Impact Factor Is to Be Preferred

Abstract

In this article, I show that the distribution of citations to papers published by the top 30 journals in the category Cardiac & Cardiovascular Systems of the Web of Science is extremely skewed. This skewness is to the right, which means that there is a long tail of papers that are cited much more frequently than the other papers of the same journal. The consequence is that there is a large difference between the mean and the median of the citation of the papers published by the journals. I further found that there are no differences between the citation distributions of the top 4 journals European Heart Journal, Circulation, Journal of the American College of Cardiology, and Circulation Research. Despite the fact that the journal impact factor (IF) varied between 23.425 for Eur Heart J and 15.211 for Circ Res with the other 2 journals in between, the median citation of their articles plus reviews (IF Median) was 10 for all 4 journals. Given the fact that their citation distributions were similar, it is obvious that an indicator (IF Median) that reflects this similarity must be superior to the classical journal impact factor, which may indicate a nonexisting difference. It is underscored that the IF Median is substantially lower than the journal impact factor for all 30 journals under consideration in this article. Finally, the IF Median has the additional advantage that there is no artificial ranking of 128 journals in the category but rather an attribution of journals to a limited number of classes with comparable impact.