Global myeloma research clusters, output, and citations: A bibliometric mapping and clustering analysis

Background: International collaborative research is a mechanism for improving the development of dis-ease- specific therapies and for improving health at the population level. However, limited data are available to assess the trends in research output related to orphan diseases. Methods and Findings: We used bibliometric mapping and clustering methods to illustrate the level of fragmentation in myeloma research and the development of collaborative efforts. Publication data from Thomson Reuters Web of Science were retrieved for 2005-2009 and followed until 2013. We created a database of multiple myeloma publications, and we analysed impact and coauthorship density to identify scientific collaborations, developments, and international key players over time. The global annual publication volume for studies on multiple myeloma increased from 1,144 in 2005 to 1,628 in 2009, which represents a 43