The Author Impact Factor as a Metric to Evaluate the Impact of Neurosurgical Researchers

OBJECTIVE: The objective of this study was to assess the Author Impact Factor (AIF) as a useful metric and as a complement to the h-index among neurosurgical researchers. METHODS: The 5-year AIF and h-index were compared among 3 groups of researchers: 1) the 100 most prolific of all time within general neurosurgical journals ("Experienced"), 2) the 100 most prolific during the 2015-2019 period within general neurosurgical journals ("Trending Group"), and 3) the 100 postgraduation year 7 neurosurgical residents with the highest h-index ("Amateur"). RESULTS: The Amateur group had a lower median h-index than the Experienced (6 vs. 55; P < 0.001) and Trending (6 vs. 43; P < 0.001) groups. The highest h-index of the Amateur group (24) was lower than the first quartile of the Experienced (46.25) and Trending (26.00) groups. The Amateur group had a lower median 5-year AIF than the Experienced (2.15 vs. 3.17; P < 0.001) and Trending (2.15 vs. 2.85; P = 0.02) groups. Unlike the h-index, the gap between the 5-year AIF distribution of the Amateur group and other groups was not profound. Although there was a positive correlation between the metrics in the 3 groups, they did not proxy for each other. For instance, while the h-index of some experienced authors that have not published recently was high, their AIFs were zero. Also, some Amateur authors published very impactful articles and had a high 5-year AIF. However, since their number of publications is inevitably low, their h-index were low. CONCLUSIONS: The AIF provides intuitive and complementary information to the h-index regarding the research output of neurosurgical authors.