title: [Original articles in the Netherlands Tijdschrift voor Geneeskunde in the second part of the 20th century: type of research described and the number and background of authors].
abstract: OBJECTIVE
  To determine the quantitative changes in methods and number of authors of original articles (OA) describing a (medical) scientific study in the Nederlands Tijdschrift voor Geneeskunde (NTvG) during 6 volumes in the second part of the 20th century.
  
  
  METHODS
  Retrospective bibliometric.
  
  
  METHODS
  All OA published in 1949, 1959, 1969, 1979, 1989 and 1999 were screened on describing a (medical) scientific study, the method used, the number of authors, (medical) students or interns being part of the author list, the number of disciplines of the authors and the institutes where the authors did the study.
  
  
  RESULTS
  The volumes mentioned contained 888 OA. The percentage of OA describing the used method increased from 47 in 1949 to 98 in 1999. In these OS 52% of the designs were retrospective. The proportion of prospective studies increased, but never met 25% of all OA. The median number of authors increased from 1 (range: 1-5) in 1949 to 5 (1-16) in 1999. The median number of disciplines of the authors increased from 1 (1-2) in 1949 to 3 (1-6) in 1999. The percentage of OA with students or interns being part of the author list varied from 1 in 1949 to 13 in 1999. In 1969-1999 most OA were received from authors from universities or academic hospitals. The percentage of OA received from authors from academic hospitals in collaboration with general hospitals increased from 0 in 1949 to 15 in 1999. Randomized clinical trials and prospective studies were mainly received from authors from universities or academic hospitals. The part of retrospective studies was largest among OA received from authors from general hospitals (58%).
  
  
  CONCLUSIONS
  In the second part of the 20th century the OA published in the NTvG changed. The number of authors increased. In recent years most authors were from universities or academic hospitals, although the proportion written by authors from these institutes in collaboration with those from general hospitals increased. Most OA described retrospective studies, the proportion received from authors from general hospitals being the largest. The percentage of OA describing prospective studies increased over the years.
authors.forename: J J
authors.initials: JJ
authors.lastname: van Ieperen
authors.forename: A J
authors.initials: AJ
authors.lastname: Overbeke
authors.forename: W
authors.initials: W
authors.lastname: Hart
mesh_terms: D001319:Authorship; D015706:Bibliometrics; D006801:Humans; D009426:Netherlands; D010506:Periodicals as Topic / Q000706:statistics & numerical data* / Q000639:trends; D011446:Prospective Studies; D016032:Randomized Controlled Trials as Topic / Q000706:statistics & numerical data; D012106:Research / Q000706:statistics & numerical data*; D012189:Retrospective Studies
vernacular_title: Oorspronkelijke stukken in het Nederlands Tijdschrift voor Geneeskunde in de tweede helft van de 20e eeuw: aard van de beschreven onderzoeken en aantal en achtergrond van de auteurs.