Cross-sectional examination of current and future trends and attributes of the presidents of the American Association of Neurological Surgeons and the Congress of Neurological Surgeons societies

Abstract

Objective

The present study aimed to analyze the academic attributes of the presidents of the American Association of Neurological Surgeons (AANS) and the Congress of Neurological Surgeons (CNS) over the past four decades to elucidate the trajectories of these societies' leaderships.

Methods

Forty-three AANS and 43 CNS presidents of the past four decades were identified. Demographic and research productivity data were collected from publicly available sources.

Results

Compared to AANS presidents, CNS presidents were younger (median = 48 years vs. 59.5 years; p < 0.001), had fewer years of practice prior to their election (15 years vs. 28 years; p < 0.001), had higher NIH funding rate (37.2% vs. 11.6%; p = 0.01), and higher rate of practicing at academic institutions (93% vs. 74.4%; p = 0.04). The CNS presidents had a comparable median number of publications at election (AANS: 72 vs. CNS: 94 publications, p = 0.78) but a higher median h-index scores (AANS: 28 vs. CNS: 59; p = 0.04). In the multiple linear regression analysis, vascular subspecialty (β = 0.21 [95% CI: 0.09–0.34]; p = 0.002) and practicing in a non-academic institution (β = 0.23 [95% CI: 0.08–0.39]; p = 0.007) were predictors for later election for AANS presidency.

Conclusions

We characterized the attributes of AANS and CNS presidents to serve as useful references for career trajectories for junior neurosurgeons and trainees. Research and academic presence seem to be associated with early election to both societies.

1. Introduction

On October 10, 1931, a group of neurosurgeons, namely R. Glenwood Spurling, Van Wagenen, Eustace Semmes, and Temple Fay, met at the Hotel Raleigh in Washington, D.C., and laid out the ground rules of establishing the Harvey Cushing Society, which later became the American Association of Neurological Surgeons (AANS).¹ Many neurosurgeons at the time felt that the existing Society of Neurological Surgeons was overly exclusive, prompting this initiative.¹ After the blessing of Dr. Cushing, the society held its first meeting in Boston on May 6, 1932. The society elected William P. Van Wagenen as the first president and committed to electing a new president annually.^1,2

In a similar attempt, several neurosurgeons envisioned and established an additional society called the Congress of Neurological Surgeons (CNS) after returning from World War II on May 10, 1951.³ The society's name was chosen carefully, excluding the word ‘American’ to reflect its vision of inclusivity beyond the Atlantic and offering membership to young neurosurgeons worldwide with a 45-year age limit.³ The first CNS meeting was held in 1951 in Memphis, TN.³ The society then continued its annual meetings, electing a new president yearly. The two societies evolved and expanded simultaneously, serving the neurosurgical community while preserving their distinct objectives and purposes.^3,4

Over the years, the bylaws of both the AANS and CNS have evolved in tandem with the changing landscape of neurosurgery and societal norms. Initially, the AANS bylaws reflected the founders' desires to ensure a breadth of representation within the field, outlining the annual election of a president to foster rotating leadership. The election process was grounded in the principles of democracy, acknowledging every member's equal rights to lead the society. The CNS, meanwhile, instituted an age limit in its bylaws to maintain its founding vision of fostering youthful vigor in neurosurgery. This unique stipulation underscores the society's commitment to empowering young professionals in the field. Membership stipulations, too, have adapted to changing times. The AANS, initially created as a response to perceived exclusivity, focused on creating an inclusive environment that valued diverse voices in neurosurgery. On the other hand, the CNS, with its term ‘Congress’ and lack of the term ‘American', intended to represent a truly global community of neurosurgeons, thereby extending its reach beyond the Atlantic. Both societies have since continually refined their bylaws to stay attuned to the shifting contours of the neurosurgical field. This evolution of the bylaws mirrors the shift in societal norms and the recognition of neurosurgery as a global and dynamic profession.

Considering the storied history of these societies and their leadership, we sought to analyze the leadership qualities and attributes of these two societies, in terms of training, practice patterns, and geographic location. Given the lack of data from previous generations, we focused our analysis on leadership in the last four decades.

2. Methods

2.1. President and career attribute selection

A list of the AANS and CNS presidents during the last four decades was obtained from the official websites of the AANS (https://www.aans.org) and CNS (https://www.cns.org) societies. Forty-three AANS and 43 CNS presidents were identified. President names and election dates were collected from the corresponding websites (i.e., AANS and CNS websites). The following variables were collected for all presidents: age, sex, residency program attended, residency geographical region, base of practice at time of election, practice geographical region, practice type, number of years in practice prior to the election, neurosurgical subspecialty, total number of publications, total publications obtained prior to election, h-index, additional degrees obtained prior to the election, history of National Institutes of Health (NIH) funding, number of R01 grants, and total NIH funding amount.

2.2. Data collection

As of October 2022, the AANS and CNS official websites – corroborated by Society of Neurological Surgeons (SNS) biographies (https://www.societyns.org/) and online curriculum vitae – were used to determine the year of presidency election (N = 66; 100%), age at election (N = 60; 91%), residency program attended (N = 66; 100%), location of practice at election (N = 66; 100%), subspecialty (N = 66; 100%), academic position at election (N = 66; 100%), additional degrees (N = 66; 100%). The presidents' residency programs and the location of practice at the election were classified based on geographical regions, using United States Census Bureau-designated regions and divisions.⁵

Additionally, AANS and CNS presidents' subspecialties were determined using the primary subspecialty listed on AANS or CNS profiles (N = 59; 89%). If no subspecialty was listed on a given AANS or CNS profile, curriculum vitae was searched for records of fellowship training to determine the subspecialty interest. The subspecialty focus was deemed general if the additional search methods could not find a subspecialty focus. In sum, 90.9% (n = 60) of total presidents were subspecialists and grouped as vascular, skull base, neuro-oncology, pediatric, functional/epilepsy, and spine/trauma.

The total publications at time of election and h-index scores of presidents at the time of study were collected using the Scopus database (https://www.scopus.com/). Federal funding has been shown to reflect academic productivity and accordingly was included as a metric in this study.⁶ Concordant with previous literature,⁷ The NIH RePORTER database (https://reporter.nih.gov/) was used to identify AANS and CNS presidents that received NIH grants over the course of their careers; presidents who were not included in the report were assumed to never have been funded by NIH grants due to the high quality of the database.

2.3. Statistical analysis

Continuous variables were reported as medians and interquartile ranges (IQR), while categorical variables were reported as frequencies and percentages. Chi-square was used to test differences between categorical variables, while Mann–Whitney U-tests were used to test the difference between continuous variables. Pearson correlation coefficient was used to identify linear correlations and trends of multiple factors across the four decades. Two multiple regression models for AANS and CNS presidents, separately, were conducted to investigate factors influencing the years of practice prior to the election. Non-linearity, heteroscedasticity, and the presence of influential values were tested in the models. The models suffered from heteroscedasticity; therefore, the outcome variable (years of practice prior to election) was log-transformed to reduce heteroscedasticity. A two-tailed p-value <0.05 was deemed to be significant for all analyses. R Program (Version 4.1.1, 2021.09.0 RStudio, Inc., R Foundation for Statistical Computing, Vienna, Austria) was used for all statistical analyses.

3. Results

3.1. AANS and CNS presidents characteristics

Since 1980, 43 AANS and 43 CNS presidents have been elected yearly. The median president age at election was 59.5 years (IQR, 56–61.8) in the AANS group and 48 years (IQR, 46–48) in the CNS group (Table 1; p < 0.001). Mirroring the age difference between the two societies' presidents, the median years of practice at the time of election was higher among AANS presidents (28 years [IQR, 25–30]), compared to CNS presidents (15 years [IQR, 14–16]; p < 0.001). AANS presidents’ age has been within a constant range during the past four decades and no linear correlation with time was found (Pearson correlation coefficient [r] = 0.22 [95% CI: −0.10–0.51]; p = 0.18; Fig. 1A). However, among CNS presidents, age has significantly increased with time (r = 0.55 [95% CI: 0.30–0.74]; p < 0.001; Fig. 1A). However, the range of years of practice prior to the election has been constant during the past four decades among both AANS (r = −0.14 [95% CI: −0.18–0.43]; p = 0.39; Fig. 1B) and CNS (r = 0.16 [95% CI: −0.15–0.44]; p = 0.30; Fig. 1B) presidents. While only two women were among the elected AANS presidents during the past four decades, all CNS presidents have been males (Table 1; p = 0.47). Almost all AANS presidents were white (N = 42; 97.7%), while CNS presidents have an insignificant less white race predominance (N = 37; 86%; p = 0.12). The rest of the CNS presidents were Asians (3; 7%), Middle Eastern or North African (2; 4.7%), and African American (N = 1; 2.3%).

Table 1.

Comparative table of cohort demographics and characteristics.

Variable	All (N = 86)	AANS (N = 43)	CNS (N = 43)	P-value
Age, median (IQR)	50 (47.5–59)	59.5 (56–61.8)	48 (46–48)	< 0.001
Mele sex, No. (%)	84 (97.7)	41 (95.3)	43 (100)	0.47
Race				0.12
White	79 (91.9)	42 (97.7)	37 (86)
Asian	3 (3.5)	0	3 (7)
Middle Eastern or North African	2 (2.3)	0	2 (4.7)
African American	1 (1.2)	0	1 (2.3)
Unknown	1 (1.2)	1 (2.3)	0
Years in practice prior to election, median (IQR)	19 (15–28)	28 (25–30)	15 (14–16)	< 0.001
Practice type at election				0.04
Academic	72 (83.7)	32 (74.4)	40 (93)
Non-academic	14 (16.3)	11 (25.6)	3 (7)
Department chairmen at the time of election	31 (36)	17 (39.5)	14 (32.6)	0.65
Not a department chairman at time of election, but held a department chair previously	2 (3.6)a	2 (7.7)*	0	0.41
Had prior service in the same society	37 (43)	10 (23.3)	27 (62.8)	< 0.001
Had prior leadership in another neurosurgical society	70 (81.4)	37 (86)	33 (76.7)	0.28
Prior CNS presidency before election for AANS		8 (18.6)
Presidents with NIH funding	21 (24.4%)	5 (11.6)	16 (37.2)	0.01
Number of R01s per NIH-funded president, median (IQR)	0 (0–5)	0 (0–0)	0.5 (0–5.8)	0.27
Total amount of grant, median (IQR)	$977,136 (440,170–3,163,319)	$1,492,678 (358,020–1,586,889)	$972,444.5 (594,382–3,408,050.8)	0.69
Number of publications at election, median (IQR)	92 (42–148)	72 (30–165)	94 (57–143)	0.78
H-index, median (IQR)	40.5 (22–57)	28 (16–52)	59 (31–59.5)	0.04

Data are reported as medians (IQR), or frequencies (%).

IQR, interquartile range.

^aThe percentage is relative to the presidents who were not holding a department chair at the time of election.

Fig. 1.

Scatter plot of president age (1. A; AANS: r = 0.22 [95% CI: −0.10–0.51]; p = 0.18; CNS: r = = 0.55 [95% CI: 0.30–0.74]; p < 0.001) and number of years of practice (1. B; AANS: r = −0.14 [95% CI: −0.18–0.43]; p = 0.39; CNS: r = 0.16 [95% CI: −0.15–0.44]; p = 0.30) at election.

3.1.1. Training and location of practice

The 86 presidents of both societies were trained across the country at various training programs that did not differ by society (p = 0.14). Among the AANS presidents, the most frequent residency programs were the Washington University in St. Louis (N = 6), University of Tennessee (N = 4), Massachusetts General Hospital (N = 3), and Columbia University (N = 3) (Fig. 2A). For the CNS presidents, the University of Pittsburgh (N = 4), University of Michigan (N = 4), and Massachusetts General Hospital (N = 4) were the most common neurosurgery residency programs attended (Fig. 2B). The states in which presidents trained differed by society (p = 0.03). Six AANS presidents trained in Missouri and 6 others in New York state, while 6 CNS presidents trained in Pennsylvania and 5 in Massachusetts (Fig. 2C and D). The geographical regions of residency training also differed by society (p = 0.02). The south was where most AANS presidents (N = 24; 59%) completed their residency training, whereas the northeast was the most common region where CNS presidents (N = 15; 36.6%) had their residency training (Fig. 2E and F).

Fig. 2.

Pie chart of residency training programs among AANS (2. A) and CNS (2. B) presidents (p = 0.14); Geographical maps of residency training locations of AANS (2. C) and CNS (2. D) presidents by state (p = 0.03); pie chart of Residency Training of AANS (2. E) and CNS (2. F) Presidents by United States Regions (p = 0.02); two AANS president and two CNS president were trained in Canada, and they were not included in the figure.

At the election, a higher rate of presidents practicing at non-academic institutions was found among AANS presidents (N = 11; 25.6%) compared to CNS presidents (N = 3; 7%; p = 0.04; Table 1). However, neither the institution of practice (p = 0.34; Fig. 3A and B) nor the geographical state (p = 0.26; Fig. 3C and D) differed by society, and the practice of most AANS and CNS presidents at the time of their election was scattered across states. At the election, New York (N = 5), California (N = 4), and North Carolina (N = 4) were the most common states where AANS presidents were based (Fig. 3C). At the same time, Ohio (N = 5), Georgia (N = 3), New York (N = 3), Pennsylvania (N = 3), North Carolina (N = 3), and Florida (N = 3) were the most frequent states where CNS presidents were based (Fig. 3D). Like states, the geographical region did not differ by society (p = 0.21), and the south was the most common region where presidents of AANS (N = 22; 52.4%) and CNS (N = 16; 37.2%) societies practiced their profession (Fig. 3E and F).

Fig. 3.

Pie chart of bases of practice of AANS (3. A) and CNS (3. B) presidents (p = 0.34); geographical maps of bases of practice of AANS (3. C) and CNS (3. D) presidents by state (p = 0.26); pie chart of the bases of practice of practice of AANS (3. E) and CNS (3. F) presidents by United States regions (p = 0.21); one AANS president was based in the University of Toronto, Canada, and was not included in the figure.

3.2. Academic and research productivity

At the time of their election, all presidents who were based at academic institutions (N = 72) were full professors, while 17 (39.5%) AANS and 14 (32.6%; p = 0.65) CNS presidents held department chair positions (Table 1). Of presidents who were not chairpersons (N = 55), 2 AANS presidents had held department chairs prior to their election (p = 0.41; Table 1). Among AANS presidents, 10 (23.3%) had prior service in the society before being elected, whereas 27 (62.8%) CNS presidents had previous service in the society before their election (p < 0.001). Comparatively, 37 (86%) AANS presidents and 33 (76.7%) CNS presidents had had prior leadership roles in other neurosurgical societies before their election (p = 0.28). Of these prior leadership roles, 8 (18.6%) AANS presidents had served as CNS presidents previously.

The presidents’ subspecialties did not vary by society (p = 0.07). Most AANS and CNS presidents were subspecialized in vascular and spine/trauma (Fig. 4A and B). Eight AANS and 8 CNS presidents had additional academic degrees (Fig. 4C), with comparable rates between the societies (p = 0.05). However, 16 (37.2%) CNS presidents had NIH funding, compared to 5 (11.6%) AANS presidents (p = 0.01; Table 1). The total amount of funding was comparable – (AANS: $1,492,678 [IQR, 358,020–1,586,889] vs. CNS: $972,444.5 [IQR, 594,382–3,408,050.8]; p = 0.69). The total amount of funding among AANS (r = 0.14 [95% CI: −0.17–0.42]; p = 0.37) and CNS (r = 0.30 [95% CI: −0.003–0.55]; p = 0.05) presidents was stable during the past four decades (Fig. 5A). Similarly, among those who were NIH funded, AANS and CNS presidents had a comparable median number of R01s (AANS: 0 [IQR, 0 - 0] vs. CNS: 0.5 [IQR, 0–5.8]; p = 0.27; Table 1). CNS presidents had a higher median h-index (AANS: 28 [IQR, 16–52] vs. CNS: 59 [IQR, 31–59.5]; p = 0.04) and a comparable median number of publications at time of election (AANS: 72 publications [IQR, 30–165] vs. CNS: 94 publications [IQR, 57–143]; p = 0.78). The number of publications at the time of election has been significantly increasing with time among both AANS (r = 0.44 [95% CI: 0.14–0.66]; p = 0.004) and CNS (r = 0.53 [95% CI: 0.26–0.72]; p < 0.001) presidents (Fig. 5B).

Fig. 4.

Pie chart of the subspecialty of AANS (4. A) and CNS (4. B) presidents (p = 0.07); bar chart (4. C) of the additional degrees among the AANS and CNS presidents (p = 0.05).

Fig. 5.

Scatter plot of president number of publications at election (AANS: r = 0.14 [95% CI: −0.17–0.42]; p = 0.37; CNS: r = 0.30 [95% CI: −0.003–0.55]; p = 0.05).

3.3. Multivariate analysis of the duration of practice before election

Two multiple regression models were generated for each society's presidents' group to investigate whether any factor influenced the number of years of practice prior to the presidency election. The variables included president race, residency geographical region (Northeast, South, Midwest, West), geographical region of the location of practice at the time of the election, subspecialty focus (vascular, skull base, neuro-oncology, pediatric, functional/epilepsy, and spine/trauma), type of additional degree(s) (Ph.D., MSs, MBA, JD), type of practice at the time of election (academic or non-academic), acquisition of an NIH grant, number of publications at the election, holding a department chair position, prior leadership in other neurosurgical society, prior service in the same society, and prior CNS presidency (in AANS model only).

The AANS (F [21, 14] = 3.72, p = 0.007, R² = 0.85) and CNS (F [25, 11] = 1.46; p = 0.26, R² = 0.77) models were conducted to predict the years of practice before presidency election. With controlling the other variables, vascular subspecialty (β = 0.21 [95% CI: 0.09–0.34]; p = 0.002) and practicing in a non-academic institution (β = 0.23 [95% CI: 0.08–0.39]; p = 0.007) were predictors for later election for AANS presidency. In contrast, none of the factors significantly predicted election recency among the CNS society, although the results showed multiple univariable trends in research and academic productivity.

3.3.1. Early versus late presidents

Despite AANS presidents from 2001 to 2022 sharing similar demographics, training, and practice with presidents from 1980 to 2000 (Supplementary Table 1), their CNS counterparts differed significantly in some aspects. CNS presidents from 2001 to 2022 were older at election (48.0 years, [IQR 48.0-49.0] vs. 46.0 years, [IQR 45.0-47.3], p < .001), had longer pre-election practice (16.0 years [IQR 15.0-16.0] vs. 15.0 years [IQR 13.0-15.0], p = .02), and had more publications (123.5, IQR 57.3-190.3 vs. 58.0, IQR 26.0-92.0, p = .01) (Supplementary Table 2).

4. Discussion

Since their establishment, the AANS and CNS societies have driven the development and advancement of neurosurgery and fostered a spirit of scientific advancements. To understand these societies' leadership attributes, we analyzed the data of the presidents of these two societies during the past four decades. Our results indicate a general similarity between these two societies' presidents, with some differences and trends as time evolved.

In our analysis, CNS presidents were significantly younger (48 years [IQR, 46–48]) than AANS presidents (59.5 years [IQR, 56–61.8], p < 0.001). This is primarily due to the age limit that was established by the founding fathers of the CNS society.³ That said, we found that the age of CNS presidents has been increasing with time, indicating that CNS is progressively electing older neurosurgeons, approaching the age range of AANS presidents. According to the most recent CNS society bylaws, the age limit had been increased to 49.⁸⁷ Interestingly, only the AANS society had presidents who were women in the past 4 decades (2 total, 2.3%). These results are lower than the general female representation in the field of neurosurgery (12.1%).⁹ However, given the significant growth of women in neurosurgery, we expect and encourage an increase in women holding leadership positions in various neurosurgical societies.

Interestingly, the geographical state and location of residency programs differed by society. While more AANS presidents trained in Missouri and New York states, more CNS presidents were trained in Pennsylvania and Massachusetts. However, when examining the training sites by geographical regions, we found that most AANS presidents were trained in the South, while most CNS presidents had their training in the Northeast. In contrast, the geographical states and regions where presidents were practicing at the time of election were not different by society. Additionally, we found a significantly higher rate of holding academic practices at the time of election among CNS than AANS presidents. Based on the bylaws of these two societies, there were no requirements concerning the type of practice for presidency election.^8,10 These data may imply more emphasis on academic merit among the CNS society, contrasting more emphasis on clinical seniority among the AANS society, as evidenced by the significant age difference between the two societies’ presidents (48 years [IQR, 46–48] vs. 59.5 years [IQR, 56–61.8], p < 0.001).

Current eligibility criteria for presidential election, as stated in the bylaws of both societies, are indicative of the societies' evolving principles and should be taken into consideration by future presidential hopefuls. The AANS requires candidates to have demonstrated history of contribution to the society, without specific mention of age or gender. On the other hand, the CNS bylaws indicate an age limit for presidential candidates, although this limit has been increased in recent years, demonstrating a trend towards electing more experienced individuals. While no explicit gender preferences are stated in either society's bylaws, the underrepresentation of women in these leadership positions suggests a potential area for continued development and evolution of the bylaws to promote increased diversity and equality. Furthermore, while academic achievement and a track record of leadership roles in other neurosurgical societies are not explicitly required, our data suggest these aspects may play a significant role in the election outcomes. Thus, future candidates for presidency should be aware of these unwritten expectations and strive to contribute meaningfully to their societies, excel academically, and engage in leadership roles in the neurosurgical community.

Most AANS and CNS presidents specialized in vascular or spine/trauma. These results are concordant with another study that examined the research productivity of neurosurgical residents and found these two subspecialties to be the most common fields of their research, possibly, indicating more active faculties and research output in these subspecialties.¹¹ Flanigan et al⁷ studied the neurosurgical department chairs in the United States and found that most chairs were specialized in vascular and skull base/tumors. Similarly, Plute et al¹² showed the vascular and spine/trauma were the most common subspecialities focus among United States neurosurgery program directors. This might likely reflect the rate of specialization in these subspecialties among all neurosurgeons in the field.¹³

Although 39.5% of AANS and 32.6% of the CNS presidents were holding department chair positions at the time of election, they were more senior in age than the average neurosurgery department chairperson.⁷ We found that CNS presidents had a higher rate of NIH funding (37.2% vs. 11.6%, p = 0.01) but a comparable median number of R01s (0.5 [IQR, 0–5.8] vs. 0 [IQR, 0 - 0], p = 0.27) compared to AANS presidents. However, the total amount of funding acquired at the time of election was stable over time among both societies’ presidents. Comparatively, 23% of the neurosurgery department chairs in the United States had NIH R01 grants.⁷ While the number of publications (AANS: 72 vs. CNS: 94; p = 0.78) was comparable among the presidents of both societies, CNS presidents had a higher median h-index score (AANS: 28 vs. CNS: 59; p = 04). Khan et al¹³ analyzed the research productivity of 1225 academic neurosurgeons in the United States and found mean h-index scores of 24 and 31 among full professors and department chairs, respectively. Similarly, Spearman et al¹⁴ calculated the Google Scholar h-index for 1120 academic neurosurgeons; full professors and department chairs had 19 and 22 h-index score, respectively. These data illustrate that AANS and CNS presidents had higher h-index scores than the average full professors and department chairs, emphasizing that highly merited academic neurosurgeons typically lead these societies.

Ten (23.3%) AANS presidents and 27 (62.8%) CNS presidents had served in the same society before being elected (p < 0.001). These data illustrate a gradual claiming to a society presidency and a pattern of election based on an internal ladder, probably to ensure a candidate's capability and allow for exposure before their election. Additionally, we found 86% of AANS presidents and 76.7% of CNS presidents had had a prior leadership role in other neurosurgical societies before the election for AANS or CNS presidency. Of all AANS presidents, 18.6% had been CNS presidents before their AANS presidency. These data highlight the general interest in leadership roles among these societies' presidents.

4.1. Limitations

The present study endures several inherent limitations. First, the data were not acquired directly from the presidents and instead were extracted from electronic resources that are – except RePORTER and Scopus – potentially outdated. Second, we restricted the study period to the past four decades to limit the heterogeneity and maximize consistency among president characteristics, resulting in a relatively small sample size. Additionally, we could not thoroughly investigate the factors predicting presidency election as the study lacked data on the general pool of neurosurgeons at each time period. Therefore, it would be interesting for future studies to analyze all neurosurgeons with available data examining such factors affecting their probability of holding leadership positions in neurosurgical societies.

5. Conclusion

This study delineated AANS and CNS presidents’ current characteristics and attributes and predicted future trends to serves as a useful reference of career trajectories for young neurosurgeons and trainees. AANS and CNS presidents share many commonalities, such as high research and academic productivity and academic rank. Research and academic presence seem to be associated with early election to both societies.

Ethical approval

No patient approval was needed.

Funding

This research did not receive any specific grant from funding agencies in the public, commercial or not-for-profit sectors.

CRediT authorship contribution statement

Othman Bin-Alamer: Methodology, Writing – original draft, Data curation, Formal analysis, Investigation, Writing – review & editing. Tritan Plute: Data curation, Methodology, Writing – original draft. Arka N. Mallela: Writing – review & editing, Methodology. Rachel Jacobs: Methodology, Writing – review & editing. Constantinos G. Hadjipanayis: Methodology, Writing – review & editing. D. Kojo Hamilton: Methodology, Visualization, Writing – review & editing. Joseph C. Maroon: Resources, Writing – review & editing, Investigation, Validation. L. Dade Lunsford: Methodology, Supervision, Validation, Writing – review & editing. Robert M. Friedlander: Writing – review & editing, Methodology. Hussam Abou-Al-Shaar: Investigation, Formal analysis, Supervision, Conceptualization, Methodology, Project administration, Resources, Validation, Visualization, Writing – original draft, Writing – review & editing.

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

None.

Abbreviations

AANS

(American Association of Neurological Surgeons)

CNS

(Congress of Neurological Surgeons)

NIH

(National Institutes of Health)

SNS

(Society of Neurological Surgeons)

IQR

(interquartile ranges)

CEO

(Chief Executive Officer)

Appendix A. Supplementary data

The following are the Supplementary data to this article.