The contributor roles for randomized controlled trials and the proposal for a novel CRediT-RCT.

Background: The past decade has witnessed a rapid increase in the number of contributors per article, which has made explicitly defining the roles of each contributor even more challenging. The Contributor Roles Taxonomy (CRediT) was developed to explicitly define author roles, but there is a lack of empirical data on how CRediT is used in clinical trials. This study aimed to provide empirical data on the use of CRediT in randomized controlled trials (RCTs) and discuss some limitations of CRediT. A new taxonomy (CRediT-RCT) is proposed to explicitly define the author roles in RCTs.

Methods: The electronic database of PubMed was searched from July 2017 to October 2019 to identify component trials with a randomized controlled design. Publications from the Public Library of Science (PLoS) were included because they embed the CRediT roles within the authors' metadata rather than solely as a separate paragraph of text.

Results: A total of 446 articles involving 4,185 authors were included in the study. Most authors participated in the study's conceptualization (44.9%) and investigation (48.8%), but only a fraction of the authors participated in software management (7.4%). Many CRediT roles were correlated with each other: the strongest correlation was the one between funding acquisition and conceptualization (correlation metric =0.39), followed by the one between conceptualization and methodology (0.37). The authors who acquired funding (OR: 2.06; 95% CI: 1.54-2.76; P<0.001), did project administration (OR: 1.54; 95% CI: 1.17-2.03; P=0.002), performed supervision (OR: 2. 60; 95% CI: 1.93-3.52; P<0.001), wrote the original draft (OR: 4.83; 95% CI: 3.54-6.60; P<0.001), or were the first author (OR: 7.85; 95% CI: 5.71-10.87; P<0.001), were more likely to be the corresponding author. Also, while the original draft writing was significantly associated with the designation of the first author (OR: 37.49; 95% CI: 25.29-57.57; P<0.001), the first author did not perform review and editing (OR: 0.55; 95% CI: 0.40-0.75; P<0.001), supervision (OR: 0.49; 95% CI: 0.36-0.67; P<0.001), or resource management (OR: 0.71; 95% CI: 0.50-1.00; P=0.053). We further propose a novel Contributor Roles Taxonomy for Randomized Controlled Trials (CRediT-RCT) which includes 10 roles.

Conclusions: The present study provides empirical data on the use of CRediT for RCTs, and some limitations of the taxonomy are discussed. We further propose a new CRediT-RCT which includes 10 roles.