What can we learn from top-cited articles in inflammatory bowel disease? A bibliometric analysis and assessment of the level of evidence

Background and objectives Despite increasing number of publications in inflammatory bowel disease (IBD), no bibliometric analysis has been conducted to evaluate the significance of highly cited articles. Our objectives were to identify the top-cited articles in IBD, assessing their characteristics and determining the quality of evidence provided by these articles. Design and outcome measures IBD and related terms were used in searching the Web of Science to identify English language articles. The 50 top-cited articles were analysed by year, journal impact factor (JIF), authorship, females in authorship, institute, country and grants received. The level of evidence was determined using the Oxford Centre for Evidence-Based Medicine guidelines. Results The number of citations varied from 871 to 3555 with a total of 74 638, and a median 1339.50 (IQR=587). No correlations were found between the number of citations and number of years since publication (r=0.042, p=0.771), JIF (r=0.186, p=0.196), number of authors (r=0.061, p=0.674), females in authorship (r=0.064, p=0.661), number of institutes (r=0.076, p=0.602), number of countries (r=0.101, p=0.483) or number of grants (r=-0.015, p=0.915). The first authors were from the USA (n=24), the UK (n=6), Germany (n=5), France (n=5), Belgium (n=3) and Canada (n=3). The levels of evidence were 12 articles at level 1b, 9 articles at level 3a and 15 articles at level 3b and fewer were at other levels. Conclusions Research papers represented 66% of articles. The majority of items have reasonably high levels of evidence, which may have contributed to the higher number of citations. The study also shows a gender gap in authorship in this area.