Recent trends in biomedical informatics: a study based on JAMIA articles

Abstract

In a growing interdisciplinary field like biomedical informatics, information dissemination and citation trends are changing rapidly due to many factors. To understand these factors better, we analyzed the evolution of the number of articles per major biomedical informatics topic, download/online view frequencies, and citation patterns (using Web of Science) for articles published from 2009 to 2012 in JAMIA. The number of articles published in JAMIA increased significantly from 2009 to 2012, and there were some topic differences in the last 4 years. Medical Record Systems, Algorithms, and Methods are topic categories that are growing fast in several publications. We observed a significant correlation between download frequencies and the number of citations per month since publication for a given article. Earlier free availability of articles to non-subscribers was associated with a higher number of downloads and showed a trend towards a higher number of citations. This trend will need to be verified as more data accumulate in coming years.

Figure 1

Breakdown of number of accepted articles (line plot, right axis), average number of citations for articles published each year from 2009 to 2012 (bar plot, left axis), grouped by year in which the citation appeared (X-axis). (A) and (B)–(J) show the breakdown of citations for all articles and for articles in nine different categories, respectively. Note that the scale for the right axis, which represents the number of published articles, varies depending on the topic, while the left axis is fixed. ACPA, average number of citations per article; NLP, natural language processing.

Figure 2

Downloads per month (DPM) versus citations per month for all articles in the past 4 years. DPM include full-text online views and PDF downloads.

Figure 3

Boxplots for citations per month displaying citation trends from 2009 to 2012. (A) Boxplots of open access plus free articles and embargoed articles, and p values for comparisons that are powered to detect significant differences (β=0.2). (B) Comparisons among open access (that is, free on online publication), free (that is, free on publication in a journal issue), and embargoed articles for 2011 and 2012. Note that 2009 did not have open access or free articles, and 2010 did not have an open access option. Analyses for 2012 are preliminary given the relatively short time from publication to the time all data were collected in mid-2013.

Figure 4

Citations (in two consecutive years including year of publication) for articles published in 2010 and 2011. The difference between freely available (free in 2010 or open access plus free in 2011) and embargoed articles was evaluated using a two-sample t-test. The test was not sufficiently powered for comparisons of 2010 articles.