OBJECT: The h index is a recently developed bibliometric that assesses an 
investigator's scientific impact with a single number. It has rapidly gained 
popularity in the physical and, more recently, medical sciences.
METHODS: The h index for all 1120 academic neurosurgeons working at all 
Electronic Residency Application Service-listed training programs was determined 
by reference to Google Scholar. A random subset of 100 individuals was 
investigated in PubMed to determine the total number of publications produced.
RESULTS: The median h index was 9 (range 0-68), with the 75th, 90th, and 95th 
percentiles being 17, 26, and 36, respectively. The h indices increased 
significantly with increasing academic rank, with the median for instructors, 
assistant professors, associate professors, and professors being 2, 5, 10, and 
19, respectively (p < 0.0001, Kruskal-Wallis; all groups significantly different 
from each other except the difference between instructor and assistant professor 
[Conover]). Departmental chairs had a median h index of 22 (range 3-55) and 
program directors a median of 17 (range 0-62). Plot of the log of the rank 
versus h index demonstrated a remarkable linear pattern (R(2) = 0.995, p < 
0.0001), suggesting that this is a power-law relationship.
CONCLUSIONS: A survey of the h index for all of academic neurosurgery is 
presented. Results can be used for benchmark purposes. The distribution of the h 
index within an academic population is described for the first time and appears 
related to the ubiquitous power-law distribution.