title: A bibliometric study of the scientific publications on patient-reported outcomes in rheumatology.
abstract: We have conducted a bibliometric study of the scientific publications on patient-reported outcomes in the field of rheumatology.
  
  
  
  SCOPUS was the database used in this bibliometric study. We performed two searches. The main search involved selecting the documents published between 2000 and 2014 limited to top-tier journals addressing rheumatic and musculoskeletal diseases, using specific descriptors together with the operator and main descriptor "patient-reported outcomes" (PROs), and we performed a secondary search, with the following specific descriptors: "pain," "functional capacity," and "fatigue." We used bibliometric indicators for articles distribution (Price's law for the increase of scientific literature and Bradford's law for dispersion of articles). We also calculated the participation index of the different countries.
  
  
  
  A total of 983 original articles were published between 2000 and 2014. Our results confirmed the fulfilment of Price's law (correlation coefficient r = 0.9385 after linear adjustment). The average number of articles per Bradford Zone was 327.6. A total of 30 different journals were published. The type of growth for the descriptors "pain" (r2= 0.5417 compared to r2= 0.4839) and "fatigue" (r2= 06276 compared to r2= 0.5544) is exponential, whereas it is linear for the descriptor "functional capacity" (r2= 0.6769 compared to r2= 0.3779).
  
  
  
  This study revealed significant linear growth of patient-related outcomes in global terms, as well as upward trends for most of the citation-based bibliometric indices, especially significant from 2010 to 2014. Pain and fatigue have greater growth as PRO concepts.
authors.affiliation: Health Sciences Faculty, Camilo José Cela University, Madrid, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Redondo
authors.affiliation: Health Sciences Faculty, Camilo José Cela University, Madrid, Spain; Department of Rheumatology, Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IDISSC), Hospital Clinico San Carlos, Madrid, Spain. Electronic address: lleon.hcsc@salud.madrid.org.
authors.forename: Leticia
authors.initials: L
authors.lastname: Leon
authors.affiliation: Health Sciences Faculty, Camilo José Cela University, Madrid, Spain.
authors.forename: Francisco Javier
authors.initials: FJ
authors.lastname: Povedano
authors.affiliation: Department of Rheumatology, Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IDISSC), Hospital Clinico San Carlos, Madrid, Spain.
authors.forename: Lydia
authors.initials: L
authors.lastname: Abasolo
authors.affiliation: Health Sciences Faculty, Camilo José Cela University, Madrid, Spain.
authors.forename: Miguel Angel
authors.initials: MA
authors.lastname: Perez-Nieto
authors.affiliation: Health Sciences Faculty, Camilo José Cela University, Madrid, Spain; Neuropsychopharmacology Unit, Hospital 12 de Octubre Research Institute (i+12), Madrid, Spain.
authors.forename: Francisco
authors.initials: F
authors.lastname: López-Muñoz
mesh_terms: D015706:Bibliometrics; D006801:Humans; D000071066:Patient Reported Outcome Measures; D012216:Rheumatic Diseases / Q000628:therapy*; D012219:Rheumatology
keywords: Bibliometric indices; Patient-reported outcomes