title: Global myeloma research clusters, output, and citations: a bibliometric mapping and clustering analysis.
abstract: BACKGROUND
  International collaborative research is a mechanism for improving the development of disease-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.
  
  
  RESULTS
  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 co-authorship 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% increase. This increase is high compared to the 24% and 14% increases observed for lymphoma and leukaemia. The major proportion (>90% of publications) was from the US and EU over the study period. The output and impact in terms of citations, identified several successful groups with a large number of intra-cluster collaborations in the US and EU. The US-based myeloma clusters clearly stand out as the most productive and highly cited, and the European Myeloma Network members exhibited a doubling of collaborative publications from 2005 to 2009, still increasing up to 2013.
  
  
  CONCLUSIONS
  Multiple myeloma research output has increased substantially in the past decade. The fragmented European myeloma research activities based on national or regional groups are progressing, but they require a broad range of targeted research investments to improve multiple myeloma health care.
authors: Medical Library, Aalborg University Hospital, Aalborg, Denmark.
authors: Jens Peter
authors: JP
authors: Andersen
authors: Department of Haematology, Aalborg University Hospital, Aalborg, Denmark; Clinical Cancer Research Center, Aalborg University Hospital, Aalborg, Denmark; Department of Clinical Medicine, Aalborg University, Aalborg, Denmark.
authors: Martin
authors: M
authors: Bøgsted
authors: Department of Haematology, Aalborg University Hospital, Aalborg, Denmark; Clinical Cancer Research Center, Aalborg University Hospital, Aalborg, Denmark; Department of Clinical Medicine, Aalborg University, Aalborg, Denmark.
authors: Karen
authors: K
authors: Dybkær
authors: Department of Hematology Sahlgrenska Hospital, Gothenburg, Sweden; European Myeloma Network Board, Aalborg, Denmark.
authors: Ulf-Henrik
authors: UH
authors: Mellqvist
authors: The Institute of Cancer Research Haematology & Oncology, London, United Kingdom; European Myeloma Network Board, Aalborg, Denmark.
authors: Gareth J
authors: GJ
authors: Morgan
authors: Nationales Centrum für Tumorerkrankungen, Heidelberg, Germany; European Myeloma Network Board, Aalborg, Denmark.
authors: Hartmut
authors: H
authors: Goldschmidt
authors: Department of Clinical Therapeutics, University of Athens, Alexandra General Hospital, Athens, Greece; European Myeloma Network Board, Aalborg, Denmark.
authors: Meletios A
authors: MA
authors: Dimopoulos
authors: Department of Internal Medicine II, University of Würzburg, Würzburg, Germany; European Myeloma Network Board, Aalborg, Denmark.
authors: Hermann
authors: H
authors: Einsele
authors: Universidad de Navarra, Pamplona, Spain; European Myeloma Network Board, Aalborg, Denmark.
authors: Jesús
authors: J
authors: San Miguel
authors: Department of Hematology, University of Turin, Turin, Italy; European Myeloma Network Board, Aalborg, Denmark.
authors: Antonio
authors: A
authors: Palumbo
authors: Erasmus University Hospital, Department of Hematology, Rotterdam, The Netherlands; European Myeloma Network Board, Aalborg, Denmark.
authors: Pieter
authors: P
authors: Sonneveld
authors: Department of Haematology, Aalborg University Hospital, Aalborg, Denmark; European Myeloma Network Board, Aalborg, Denmark; Clinical Cancer Research Center, Aalborg University Hospital, Aalborg, Denmark; Department of Clinical Medicine, Aalborg University, Aalborg, Denmark.
authors: Hans Erik
authors: HE
authors: Johnsen
mesh_terms: D015706:Bibliometrics; D016000:Cluster Analysis; D006801:Humans; D009101:Multiple Myeloma; D011642:Publications; D015203:Reproducibility of Results; D012106:Research; D013997:Time Factors
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