Impact Factor, h-Index, and Alternative Metrics: How Should We Measure the Impact of Publications in Plastic Surgery?

Abstract

The prestige of academic journals is largely determined based on impact factor, and the prestige of authors is based on h-indices.1,2 Despite their widespread acceptance, these citation-based metrics have inherent drawbacks, resulting in increasing interest in alternative metrics (altmetrics). Impact factors originated from researchers’ desire to gauge the “scientific prestige” of academic journals.1,3 A measure of the relative frequency with which an “average” article in a journal has been cited, impact factor is calculated by dividing the number of article citations from a particular journal by the number of publications in that journal over a 2-year period (Fig. 1). By design, this formula overvalues large-readership, far-reaching journals and undervalues niche, specialty journals with lower readership—a concern for plastic surgery journals.1,3Fig. 1.: The impact factor equation.The h-index is used to evaluate an individual researcher’s scientific output. It attempts to correlate the quantity of articles an author has published with the number of times those articles have been cited. Drawbacks include the lag of citation of publications of influential work and the limited size of the field in which an author publishes.4 Despite these shortcomings, impact factor and h-index are both heavily used within plastic surgery. A side effect of the “publish or perish” mentality, many authors are willing to pay high prices to have their research published in journals with high impact factors.1 This financial outflux is not unwarranted—having high–impact factor journal publications has been shown to help secure tenure positions, promotions, and committee appointments.3 In addition, h-indices have been cited as crucial to faculty promotion decisions.5 With the questionable relevance of these traditional measures of academic success and their continued emphasis, altmetrics have emerged. Although traditional metrics only account for research shared within the academic community, altmetrics generally account for the fact that—especially within plastic surgery—dissemination of information on the Internet and through social media platforms has risen to prominence, and scientific research is reaching a larger audience than ever before.2 The Altmetric Attention Score tracks mentions of research on platforms such as blogs, news channels, and social media, and then weights each mention to account for each platform’s degree of influence on readers.2 With the increasing popularity of online citation management programs, another altmetric is the Mendeley readership score, which is based on the frequency with which an article is “collected” in users’ personal Mendeley libraries and also accounts for the academic ranks of the researchers “collecting” an article.2 Although critics of altmetrics argue that these measures gauge the impact of research on the general public, not the scientific community, social media directly impact traditional, citation-based metrics. One article found that coverage of medical research in popular media amplifies the number of scientific citations that research receives for at least 10 years thereafter.3 With clear overlap existing between the relevance of both traditional and altmetrics of academic research in plastic surgery (Table 1), it is our view that altmetrics should not replace citation-based metrics, but should be incorporated into the evaluation of journals and of many plastic surgeons’ research prowess. Table 1. - Summary of the Meanings of Impact Factor, h-Index, and Altmetrics Term Definition Impact factor Scientific prestige of a journal, based on relative number of academic citations h-index Scientific prestige of an author, based on relative importance of an author’s publications Altmetrics Alternative citation-based metrics of a journal’s or an author’s scientific prestige; dissemination of scientific articles in nonacademic areas; influence “at large” DISCLOSURE The authors have no financial interests in this document and have received no external support related to this article.