Study Comparing Traditional Versus Alternative Metrics to Measure the Impact of the Critical Care Medicine Literature.

Our objective was to evaluate the association between traditional metrics such as Impact Factor and Eigenfactor with respect to alternative metrics. The Altmetric Attention Score for the top nine pulmonary and critical care journals was compared with Impact Factor, Eigenfactor, and citations over two time periods (2007-2011 and 2012-2016). There was a significant increase in the Altmetric Attention Score (52 from 2007 to 2011 vs 1,061 from 2012 to 2016; < 0.001) but no significant differences in Total Citations, Impact Factor, or Eigenfactor. There was a strong positive correlation between citations and Altmetric Attention Score, negative correlations between Eigenfactor and Altmetric Attention Score for most journals, and no clear association between Impact Factor and Altmetric Attention Score. Over time, the digital reach of traditional publications has increased significantly, while no significant increase was noted for the traditional metrics. These findings likely reflect discussions of articles online that are not captured by traditional metrics and hence their impact on the community at large.