Productivity of authors in the field of diabetes: bibliographic analysis of trial publications

Objective To determine whether trial publications of glucose lowering drugs are dominated by a small group of highly prolific authors (“supertrialists”) and to identify some of their characteristics. Design Bibliographic analysis of trial publications. Data sources and review methods We searched PubMed for all randomised controlled trials (RCTs) relating to glucose lowering drugs published between 1 January 1993 and 31 December 2013. From these publications we identified the 110 most prolific authors using PubReMiner. The 991 RCTs they published were examined for various characteristics such as author number, commercial sponsorship, company authorship, conflicts of interest, etc. The track record of the top 11 authors was studied in more detail. Main outcome measure Proportion of articles published by the top 110 and the top 11 authors. Results 3782 articles from 13 592 authors were identified. The top 110 authors were named in 1227 (32.4%) of all articles, and the top 11 authors in 397 (10.5%) of all articles. The top 110 authors published 991 RCTs for a median of 20 (range 4-77) RCTs per author; the top 11 published 354 RCTs for a median of 42 (36-77) RCTs per author. Of the 110 top authors, 48 were employed by a pharmaceutical company. Of the 991 RCTs, 906 were commercially sponsored. Of 704 articles that could be assessed for conflicts of interest, only 42 (6%) were considered fully independent. Medical writing assistance was acknowledged in 439 (44.3%) of 991 RCTs. Conclusion The past two decades have seen an explosive increase in the number of published clinical trials regarding glucose lowering treatment. Some authors have made a disproportionate contribution to the therapeutic evidence base; one third of the RCT evidence base on glucose lowering drug treatment for diabetes was generated by <1% of authors. Of these, 44% were company employees and 56% were academics who work closely with the pharmaceutical companies.