Researcher contributions and fulfillment of ICMJE authorship criteria: analysis of author contribution lists in research articles with multiple authors published in radiology. International Committee of Medical Journal Editors.

PURPOSE To determine the number of researchers who fulfill the International Committee of Medical Journal Editors (ICMJE) authorship criteria and to evaluate individual contributions. MATERIALS AND METHODS The author contribution lists of Radiology articles published between 1998 and 2000 with at least three authors were reviewed. The fulfillment of ICMJE criteria for authorship and the contribution percentage were assessed according to each researcher's position in the byline and nationality (American vs international), number of researchers per article, and year of publication. RESULTS Sixty-eight percent of researchers fulfilled the ICMJE authorship criteria. Position in the byline indicated a significant difference in fulfillment (P <.001): 98.9% and 85.3% for the first and second authors, respectively, and 52.8% and 66.5% for the middle and last authors, respectively. American researchers had a higher percentage (78%) of fulfillment than did international researchers (57%) (P <.001). Fulfillment decreased as the number of authors per article increased (P <.001), although there was no significant change throughout 1998-2000. The mean contribution percentages decreased greatly from first to second to last to middle authors. American researchers had a significantly larger mean contribution percentage than did international researchers. Of the total 6,686 researchers, 2,316 (35%) contributed to one or two categories. This rate was higher for middle and international authors. CONCLUSION The 68% fulfillment of criteria for authorship was closely related to the large number of researchers contributing to one category or to categories belonging to the same ICMJE criterion.