An analysis of factors contributing to PubMed's growth
During the period 20042013 more than 7.3 million journal articles were added in PubMed, a 48.9% increase from 2003. Recently launched journals showed the greater annual increase in published articles, but, overall, older journals contributed most of the articles. The change in open access articles was higher than subscription access (80.8% vs 54.7%) from 2004 to 2013. Asian (114%) and European (34.9%) first author affiliation increased at a higher rate than American publications (7.9%). English remained the predominant language of publications. USA- and England-based organizations published a gradually increasing body of literature.
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