Network Analysis of Past NASBS Presidents

Background: Past presidents of the NASBS include pioneers and leaders across multiple disciplines in skull base surgery. Since the inception of the NASBS, there have been major paradigm shifts in the management of skull base pathology. Little is known about the relative contributions and interactions of the past presidents and skull base centers.

Objectives: The primary objectives of this study are: (1) Measure academic contributions of past presidents; (2) Identify influential nodes of academic collaboration; (3) Identify opportunities for future collaboration.

Methods: Peer-reviewed publications of past presidents of NASBS from 1964 to July 2019 were identified using the Scopus author name search. Author and abstract records were collected in an SQL database for offline processing. Duplicate author profiles and alternate spellings were merged via automated similarity matching followed by manual review using institution affiliation and publication history. Network structures were constructed and analyzed using the graph-tool python library to produce a weighted co-authorship network base and compute centrality measures. Girvan–Newman clustering was applied to identify community structure. Network maps were then produced using Gephi’s network visualization software with force-directed layout algorithms.

Results: The coauthor network of 29 presidents was fully connected, with a maximum shortest-path distance between presidents of 5. The mean number of connections from each node without respect to weighting was 5.31 (SD 3.53), and the mean number of connections with weighting was 8.40 (SD 7.28). The number of unweighted connections ranged from 1 to 14 and weighted connections ranged from 0.25 to 24.7. A total of 12 members (41.4%) had weighted connections above the mean. Girvan–Newman clustering identified three communities with two that covered 93% of the network. The largest communities contained 14 and 13 presidents and had mean unweighted connections of 5.79 and 5.31 and mean weighted connections of 10.10 and 7.45, respectively. The largest community had seven presidents with magnitude of weighted connections above the mean and the next largest community had five members with weighted connections above the mean. The number of connections was correlated with h-index, both unweighted (r ² = 0.34) and weighted (r ² = 0.26).

Conclusion: Network mapping of past presidents of the NASBS helps to capture the history of the NASBS and reveals areas of concentration and influence within the specialty.