title: Comparison between two five year periods (1998/2002 and 2003/2007) on the production, impact and co-authorship of publications on tobacco and smoking by Spanish authors using the Science Citation Index.
abstract: OBJECTIVE
  The aim of this study was to compare the production, impact and co-authorship of publications by Spanish authors on smoking and tobacco between two time periods (1998/2002 vs 2003/2007) using Science Citation Index (SCI).
  
  
  METHODS
  The literature search was performed in the SCI-Expanded on 20 November 2008. All types of documents by Spanish authors were selected. The search was restricted to the title, and the key words used were "smok*" and "tobac*". The statistical analysis was descriptive (95% CI).
  
  
  RESULTS
  A total of 588 documents were obtained, with 399 (67.85%) original papers, 54 (9.18%) letters to the editor, and 35 (5.95%) editorials. Productivity increased between the 98/02 to 03/07 periods: 234 (39.8%) documents versus 354 (60.2%). We have found significant differences between the two periods (98/02 vs 03/07) in total mean annual documents (47 ± 8 vs 71 ± 16 [p=0.024]) and total mean annual original papers (34 ± 6 vs 46 ± 9 [p=0.041]). The mean number of citations per document was 14.1 ± 2.1 for 98/02 period and 5.6 ± 2.5 for 03/07 period (p=0.003). The co-authorship annual index had increased; with a mean of 6.77 signatures/document for 98/02 period to a mean of 6.87 for 03/07 period. Authors and institution networks collaborations had increased between the two periods.
  
  
  CONCLUSIONS
  Spanish production and co-authorship of documents on smoking and tobacco have increased between these two periods. The earlier period documents received more citations.
authors.affiliation: Servicio de Neumología, Hospital Infanta Elena, Valdemoro, Madrid, Spain. igo01m@gmail.com
authors.forename: José Ignacio
authors.initials: JI
authors.lastname: de Granda-Orive
authors.forename: Adolfo
authors.initials: A
authors.lastname: Alonso-Arroyo
authors.forename: Santiago José
authors.initials: SJ
authors.lastname: Villanueva Serrano
authors.forename: Rafael
authors.initials: R
authors.lastname: Aleixandre-Benavent
authors.forename: Gregorio
authors.initials: G
authors.lastname: González-Alcaide
authors.forename: Francisco
authors.initials: F
authors.lastname: García-Río
authors.forename: Carlos Andrés
authors.initials: CA
authors.lastname: Jiménez-Ruiz
authors.forename: Segismundo
authors.initials: S
authors.lastname: Solano-Reina
authors.forename: Francisco
authors.initials: F
authors.lastname: Roig-Vázquez
mesh_terms: D001319:Authorship; D016206:Databases, Bibliographic; D055811:Journal Impact Factor; D011643:Publishing / Q000706:statistics & numerical data*; D012907:Smoking; D013030:Spain; D013997:Time Factors; D014026:Nicotiana