A Proof of Concept for Applying the Radicchi Index (hf) to Compare Academic Productivity and Scientific Impact Among Medical Specialties.

Many indices have been developed to assess the impact of scientific publications by investigators, disciplines, and institutions. The h-index has emerged as a leading tool in the assessment of the productivity of authors. Differences in publication and citation opportunity among specialties create inappropriate conclusions when the h-index is used to compare authors across different disciplines. An alternative, the Radicchi index, hf, has been proposed to assess the impact of publications across disciplines. We curated a database of all articles published from 2002 to 2015 from the 3 highest impact factor medical journals: New England Journal of Medicine (NEJM), the Lancet, and the Journal of American Medical Association (JAMA). With this database, articles were categorized into medical subspecialties. We calculated the respective h-index and Radicchi index of each specialty. We found that the Radicchi index eliminated variability associated with publication and citation opportunity between different specialties when compared to the h-index. The Radicchi index is a useful measure of scientific impact and productivity that advances the h-index by allowing interspecialty comparisons. There remains a need to define a researcher's specialty designation especially if he/she conducts multidisciplinary research.