In an article posted to bioRxiv on October 22, 2015, four NIH scientists proposed a new bibliometric measure of article influence. This measure, called the Relative Citation Ratio (RCR), is presented as an alternative to using Journal Impact Factor to measure the influence of an individual article. RCR measures the citation rates of articles in a co-citation network, or the set of the articles that have been cited by articles that also cite the target article.
A beta of version of the NIH’s online tool to calculate relative citation ratio for articles in PubMed published between 1995 and 2013 can be found at iCite.