title: Reliability of disclosure forms of authors' contributions.
abstract: BACKGROUND
  The contribution disclosure forms used by medical journals to assess and confirm authorship are surveys of self-reported behaviour that follow the cognitive rules of psychometric instruments. We sought to analyze how autobiographical memory, defined as memory for events and issues related to oneself, affected the reliability of contribution forms for the judging of authorship of research articles.
  
  
  METHODS
  We conducted a prospective study, which ultimately included 919 authors of 201 articles submitted to a general medical journal from July 2001 through December 2002. A authorship disclosure form with a checklist of 11 possible contribution choices for all authors was sent first to each article's corresponding author, who was asked to fill it out for all authors. A blank form was then sent to each author individually to disclose his or her own contribution to that article. The main outcome measure was test- retest differences between the corresponding authors' self-declarations, expressed in percent as the gross difference rate (GDR) for each article.
  
  
  RESULTS
  More than two-thirds of the corresponding authors (69.7%) differed in at least 1 contribution choice between the 2 disclosure statements made about their own contributions. The reliability of their answers was low to moderate (GDRs > 10%), especially for contributions on the provision of study materials or patients or final approval of the article (GDR 22.9%), guarantor of the study (GDR 20.9%) and drafting of the manuscript (GDR 20.4%). As a proxy for their coauthors' contributions, corresponding authors also differed from them in the perception of noncorresponding authors' contributions, disagreeing in 69.4% of cases. Of the 718 noncorresponding authors, 204 (28.4%) met all the criteria for authorship set out by the International Committee of Medical Journal Editors according to the statement given by the corresponding author. When they described their own contributions, this prevalence increased to 40.5%.
  
  
  CONCLUSIONS
  Psychological factors such as autobiographical memory may confound contribution disclosures as an evaluation tool for authorship on scientific articles and affect responsible authorship and publication practices.
authors.affiliation: Department of Medical Statistics and Medical Informatics, School of Medicine, Josip Juraj Strossmayer University, Osijek, Croatia.
authors.forename: Vesna
authors.initials: V
authors.lastname: Ilakovac
authors.forename: Kristina
authors.initials: K
authors.lastname: Fister
authors.forename: Matko
authors.initials: M
authors.lastname: Marusic
authors.forename: Ana
authors.initials: A
authors.lastname: Marusic
mesh_terms: D001319:Authorship; D015706:Bibliometrics; D017523:Croatia; D030881:Disclosure; D035081:Editorial Policies; D006801:Humans; D008373:Manuscripts as Topic; D008568:Memory; D010506:Periodicals as Topic; D011446:Prospective Studies