Google Scholar journal metrics: Comparison with impact factor and SCImago journal rank indicator for nuclear medicine journals

Introduction: In the current study, we compared h5-index provided by Google Scholar (GS), impact factor (IF) provided by web of sciences (WOS), and SCImago journal rank indicator (SJR) provided by SCOPUS for quality assessment of nuclear medicine journals. Methods: 2013 h5-index, 2012 IF, and 2011 SJR of nuclear medicine journals were extracted from their publishers namely GS, WOS, and SCOPUS. Rank of each journal according to each index was provided. Spearman correlation was used for evaluation of the correlation between metrics. Results: Overall 22 journals were identified. Spearman correlation coefficients between h5-index and other journal metrics were 0.907 for 2012 IF, 0.979 for 2011 JCR, and 0.978 for 2011 SCOPUS h-index (all p-values<0.00001). Wilcoxon signed ranks test showed no statistically meaningful difference between rankings according to h5-index and other journal metrics (p values of 0.589, 0.565, and 0.542 for 2012 IF, 2011 SJR, and 2011 SCOPUS h-index respectively). Conclusion: The new GS journal metrics are reliable tools for quality assessment of the nuclear medicine journals. In our opinion, h5-index, IF, and SJR should be used in a combination as their combination would give a more holistic view of journal quality. Development of new journal metrics in addition to SJR and IF by GS should be welcomed by the scientific community.