World Neurosurg. 2018 Jul 25. pii: S1878-8750(18)31622-X. [Epub ahead of print]
BACKGROUND: In academic specialties such as neurosurgery, bibliometrics are often used to guide readers, academic institutes and researchers to make objective assessment of journals. Recently, new indices have been developed to overcome the shortcomings of the widely-used Impact Factor. The objective of our study is to investigate the correlations among six of the commonly used bibliometric indices (Impact Factor, SCImago Journal indicator, SCOPUS h-index, Google h-index, Eigenfactor, Article Influence Score) in Neurosurgical and Spinal Surgical journals.METHODS: A list of all Neurosurgical and Spinal Surgical journals is compiled using the databases of SCOPUS®, Clarivate Analytics (Thomson Reuters) and National Library of Medicine Catalog. Journals that are not surgically-orientated, non-English journals and nursing journals are excluded. Bivariate Spearman's ranking correlation tests were performed.
RESULTS: 54 journals are included, of which 14 are spine-themed. High positive correlations are obtained among the bibliometric indices of Neurosurgical (non-spinal) journals (p < 0.05 in all pairs). Median values are 1.54, 0.66, 53, 25, 0.0035 and 0.46 for Impact Factor, SCImago Journal rank indicator, SCOPUS h-index, Google h-index, Eigenfactor, Article Influence Score respectively. However, the correlations for Spinal Surgical journals are more variable, which is likely to be due to its small sample size.
CONCLUSIONS: Despite the different mathematical basis among the citation-based bibliometric indices studied, they have strong correlations in ranking Neurosurgical journals. This study provides evidence that the newer indices may be used interchangeably with the Impact Factor in this context, and they may, theoretically, mitigate some the shortcomings of the Impact Factor.
Keywords: Academic neurosurgery; Bibliometrics; Citations; Eigenfactor; Impact; h-index