Bibliometric analysis of the top-cited gastroenterology and hepatology articles

Objective: To identify the top-cited articles in gastroenterology and hepatology, and analyse their characteristics. Methods: Two searches were conducted in the Science Citation Index Expanded database; a search of 69 journals under the category 'Gastroenterology and Hepatology' (list A) and a keyword search of all journals (list B). The search results were analysed and the inter-rater coefficient of agreement between evaluators was measured using Cohen kappa . Results: The number of citations varied from 1049 to 2959 in list A and from 1929 to 5500 in list B. In both lists, the majority of articles were research papers. No significant correlations were found between the number of citations and the number of years since publication (R-2=0.00992, p=0.473 and R-2=0.00202, p=0.757, respectively). However, the mean number of citations of papers published before the year 2000 was lower than those published after 2000 (36.70 +/- 19.31 vs 106.03 +/- 39.22). No correlation was found between number of authors and the number of citations (R-2=0.04352, p=0.130), but strong correlations were found between the number of institutes involved or number of countries and the number of citations (R-2=0.275, p<0.001 and R-2=0.16181, p=0.003, respectively). Females were under-represented in authorship (45 vs 254, p=0.004). Only 21 papers (of 54) in list A were supported by grants. No correlation was found between number of grants received and the number of citations (R-2=0.02573, p=0.247). The inter-rater agreement between evaluators had a Cohen kappa coefficient 0.76-0.84. Conclusions: Top-cited articles were not only published in highly ranked journals specialising in Gastroenterology and Hepatology but also in 14 journals not specialised in this field. The number of citations correlated with the number of institutes and the number of countries involved but not with the number of grants received or the number of authors. Females were under-represented in the authorship.