Worldwide research productivity in the field of rheumatology from 1996 to 2010: a bibliometric analysis

Methods. Articles published in 39 rheumatology journals from 1996 to 2010 were screened using the Scopus database. The number of articles, citations, Hirsch indices (h-indices) and international collaborations were determined for countries or regions. Publication activity was adjusted for the top 35 countries categorized by population size and gross domestic product (GDP). Results. A total of 43 808 articles were identified. The time trend of the number of articles showed an increase of 2.95-fold between 1996 and 2010. Western Europe and northern America were the most productive world areas, producing 52.4% and 23.1% of the available literature, respectively. The USA published the most articles, followed by the UK and Germany. The USA, the UK and the Netherlands had the highest h-indices (169, 137 and 117, respectively) and ranked about the same when total citations were used. However, Ireland had the highest average citations per article (48.33), followed by Denmark (40.19) and the Netherlands (39.86). Positive associations between the total number of publications/citations and population/GDP were observed (P < 0.01). Scandinavian countries ranked the highest after adjusting for population and GDP. Conclusion. The USA and Western Europe clearly dominate the production of scientific publications in rheumatology. However, some smaller European countries have high scientific output relative to their size.