Global neurosurgery: the current capacity and deficit in the provision of essential neurosurgical care. Executive Summary of the Global Neurosurgery Initiative at the Program in Global Surgery and Social Change

Abstract

OBJECTIVE
Worldwide disparities in the provision of surgical care result in otherwise preventable disability and death. There is a growing need to quantify the global burden of neurosurgical disease specifically, and the workforce necessary to meet this demand.METHODS
Results from a multinational collaborative effort to describe the global neurosurgical burden were aggregated and summarized. First, country registries, third-party modeled data, and meta-analyzed published data were combined to generate incidence and volume figures for 10 common neurosurgical conditions. Next, a global mapping survey was performed to identify the number and location of neurosurgeons in each country. Finally, a practitioner survey was conducted to quantify the proportion of disease requiring surgery, as well as the median number of neurosurgical cases per annum. The neurosurgical case deficit was calculated as the difference between the volume of essential neurosurgical cases and the existing neurosurgical workforce capacity.RESULTSEvery year, an estimated 22.6 million patients suffer from neurological disorders or injuries that warrant the expertise of a neurosurgeon, of whom 13.8 million require surgery. Traumatic brain injury, stroke-related conditions, tumors, hydrocephalus, and epilepsy constitute the majority of essential neurosurgical care worldwide. Approximately 23,300 additional neurosurgeons are needed to address more than 5 million essential neurosurgical cases-all in low- and middle-income countries-that go unmet each year. There exists a gross disparity in the allocation of the surgical workforce, leaving large geographic treatment gaps, particularly in Africa and Southeast Asia.CONCLUSIONS
Each year, more than 5 million individuals suffering from treatable neurosurgical conditions will never undergo therapeutic surgical intervention. Populations in Africa and Southeast Asia, where the proportion of neurosurgeons to neurosurgical disease is critically low, are especially at risk. Increasing access to essential neurosurgical care in low- and middle-income countries via neurosurgical workforce expansion as part of surgical system strengthening is necessary to prevent severe disability and death for millions with neurological disease.

Full text

CLINICAL ARTICLE
ABBREVIATIONS HICs = high-income countries; LMICs = low and middle-income countries; PGSSC = Program in Global Surgery and Social Change; TBI = traumatic
brain injury; TSI = traumatic spinal injury; WFNS = World Federation of Neurosurgical Societies.
SUBMITTED June 21, 2017. ACCEPTED November 10, 2017.
INCLUDE WHEN CITING Published online April 27, 2018; DOI: 10.3171/2017.11.JNS171500.
Global neurosurgery: the current capacity and decit in
the provision of essential neurosurgical care. Executive
Summary of the Global Neurosurgery Initiative at the
Program in Global Surgery and Social Change
Michael C. Dewan, MD, MSCI,1,2 Abbas Rattani, MBe,1,3 Graham Fieggen, MD, MSc,4
Miguel A. Arraez, MD, PhD,5 Franco Servadei, MD,6 Frederick A. Boop, MD,7
Walter D. Johnson, MD, MBA, MPH,8 Benjamin C. Warf, MD,9,10 and Kee B. Park, MD1
1Global Neurosurgery Initiative–Program in Global Surgery and Social Change, Department of Global Health and Social
Medicine, Harvard Medical School, Boston, Massachusetts; 2Department of Neurological Surgery, Vanderbilt University
Medical Center, Nashville, Tennessee; 3Meharry Medical College School of Medicine, Nashville, Tennessee; 4Department of
Surgery, University of Cape Town, South Africa; 5Department of Neurosurgery, Carlos Haya University Hospital, Malaga, Spain;
6Department of Neurosurgery, Humanitas University and Research Institute, Milan, Italy; 7Department of Neurological Surgery,
University of Tennessee Health Sciences Center, LeBonheur Children’s Hospital Neurosciences Institute, Semmes-Murphey
Clinic, Memphis, Tennessee; 8Emergency & Essential Surgical Care Programme Lead, World Health Organization, Geneva,
Switzerland; 9Department of Neurological Surgery, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts;
and 10CURE Children’s Hospital of Uganda, Mbale, Uganda
OBJECTIVE Worldwide disparities in the provision of surgical care result in otherwise preventable disability and death.
There is a growing need to quantify the global burden of neurosurgical disease specically, and the workforce necessary
to meet this demand.
METHODS Results from a multinational collaborative effort to describe the global neurosurgical burden were aggre-
gated and summarized. First, country registries, third-party modeled data, and meta-analyzed published data were com-
bined to generate incidence and volume gures for 10 common neurosurgical conditions. Next, a global mapping survey
was performed to identify the number and location of neurosurgeons in each country. Finally, a practitioner survey was
conducted to quantify the proportion of disease requiring surgery, as well as the median number of neurosurgical cases
per annum. The neurosurgical case decit was calculated as the difference between the volume of essential neurosurgi-
cal cases and the existing neurosurgical workforce capacity.
RESULTS Every year, an estimated 22.6 million patients suffer from neurological disorders or injuries that warrant the
expertise of a neurosurgeon, of whom 13.8 million require surgery. Traumatic brain injury, stroke-related conditions,
tumors, hydrocephalus, and epilepsy constitute the majority of essential neurosurgical care worldwide. Approximately
23,300 additional neurosurgeons are needed to address more than 5 million essential neurosurgical cases—all in low-
and middle-income countries—that go unmet each year. There exists a gross disparity in the allocation of the surgical
workforce, leaving large geographic treatment gaps, particularly in Africa and Southeast Asia.
CONCLUSIONS Each year, more than 5 million individuals suffering from treatable neurosurgical conditions will never
undergo therapeutic surgical intervention. Populations in Africa and Southeast Asia, where the proportion of neurosur-
geons to neurosurgical disease is critically low, are especially at risk. Increasing access to essential neurosurgical care
in low- and middle-income countries via neurosurgical workforce expansion as part of surgical system strengthening is
necessary to prevent severe disability and death for millions with neurological disease.
https://thejns.org/doi/abs/10.3171/2017.11.JNS171500
KEYWORDS capacity; epidemiology; global; incidence; volume; workforce; worldwide
J Neurosurg April 27, 2018 1©AANS 2018, except where prohibited by US copyright law

M. C. Dewan et al.
J Neurosurg April 27, 20182
In 2015, the Lancet Commission on Global Surgery of-
fered a summary of the surgical burden and described
existing gaps in the provision of safe and affordable
surgical care worldwide.11 More than two-thirds of the
world’s population lack access to appropriate surgical and
anesthetic care, equating to an estimated 143 million nec-
essary surgical procedures that are left undone. This un-
treated surgical disease results in extreme economic costs
and profound disability and death.17
Within this tremendous burden of surgical disease re-
sides the contribution of neurosurgical disease. Obtaining
a reliable estimate of the volume of neurosurgical disease
requires addressing numerous challenges including sparse
epidemiological data, heterogeneous literature reporting,
and even competing denitions of disease entities. Fur-
thermore, quantifying the existing workforce of surgeons
capable of safely addressing neurological disease is dif-
cult. There exists neither a single worldwide registry of
neurosurgeons, nor even a consensus as to the requisite
training and competencies of a neurosurgeon.
Despite debate about the nature of neurosurgical dis-
ease and those capable of addressing it,1 there is grow-
ing recognition of a worldwide shortage of neurosurgeons,
particularly in low-resourced settings.2,13,20 Before pursu-
ing a targeted campaign to stem the disparity in special-
ized surgical care, a more denitive understanding of the
problem is essential, including regions with the greatest
need. In this report we summarize a body of research by
the Program in Global Surgery and Social Change aimed
at establishing the current status of neurosurgery world-
wide. Thus, we provide estimates of the global volume of
neurosurgical disease, the existing neurosurgical capacity,
and the current unmet neurosurgical need worldwide.
Methods
Volume of Neurosurgical Disease
We began by estimating the incidence of 10 conditions
encountered by neurosurgeons that form the foundation
of essential neurosurgical care: brain and spinal tumors,
hydrocephalus, traumatic brain injury (TBI), traumatic
spinal injury (TSI), neural tube defects, stroke, CNS vas-
cular anomalies, CNS infections, and epilepsy. Conditions
were identied by ranking commonly treated neurosur-
gical conditions described by an international panel of
neurosurgical providers (see Proportion Requiring Neu-
rosurgery below). Then, those conditions in which treat-
ment neglect would directly result in severe disability or
death were designated by this report as essential neuro-
surgical conditions. Notably excluded from the nal list
are degenerative spine disease and osteoporotic vertebral
fractures.15 The proportion and volume of patients suc-
cumbing to severe disability or death if these conditions
are not treated surgically is difcult to determine, particu-
larly in resource-limited settings. Due to the recognition
of limited capacity, this classication scheme of essential
neurosurgical care also excluded important conditions
such as pain disorders, spasticity, movement disorders,
and other conditions for which neurosurgical treatment
might offset disability and lost productivity. Competency
with the treatment of the 10 conditions above, however,
would equip a neurosurgeon anywhere with the ability to
treat the vast majority of patients with neurosurgical dis-
ease, and thereby most efciently avert severe disability or
premature death.
Reliable epidemiological gures were available for
two diseases (neural tube defect and stroke; http://ghdx.
healthdata.org/gbd-results-tool),10 thus our attention was
focused on the remaining conditions. National surgical
registries were available for brain and spinal tumors al-
lowing region-specic estimation of disease incidence.3
The Institute for Health Metrics and Evaluation has pub-
lished epidemiological gures for road trafc injuries in
each country, which were used to extrapolate the inci-
dence of TBI. The proportion of trafc collisions result-
ing in TBI was calculated via a meta-analysis of published
trafc injury data. Similarly, the proportion of TBI from
which trafc collisions is the mechanism of action was
calculated via a meta-analysis. Applying these ratios to the
incidence of road trafc injuries delivered an estimation of
total TBI from all causes.6
For the remaining conditions (hydrocephalus, TSI,
CNS vascular anomalies, CNS infections, and epilepsy),
an exhaustive systematic review was conducted to identify
studies reporting epidemiological data from large, popu-
lation-based cohorts. After extracting case numbers and
sample size, a meta-analysis was performed to estimate
disease incidence gures for each disease by WHO re-
gion and by World Bank income group. Finally, incidence
gures were multiplied by population estimates from the
WHO to generate estimates for the annual volume of dis-
ease globally. Detailed methodology and results are de-
scribed in detail elsewhere.3,7–9,11,16,19
Proportion Requiring Neurosurgery
Identifying the incidence of neurosurgical disease re-
quires an estimate of the proportion of neurological injury
or illness warranting surgical intervention. Some neu-
rosurgical diseases are best managed operatively, while
others require nonoperative neurosurgical management.
Some neurological conditions do not require neurosurgi-
cal expertise for optimal treatment. While surgical logs
from ideal health care systems offer reliable estimates
for surgical proportion (i.e., the fraction of neurological
conditions requiring surgery), their relevance may not be
generalizable to health care systems in differing settings.
Furthermore, we learn very little about the proportion of
disease beneting from nonoperative neurosurgical ex-
pertise or consultation. Thus, following the precedent es-
tablished by the Lancet Commission on Global Surgery,
we sought expert opinion from a broad, diverse group of
surgical providers.
Via electronic survey, nearly 200 neurosurgeons from
more than 50 countries were asked to estimate the pro-
portion of specic neurological disorders that, in an ideal
world, would require either neurosurgical operation or
consultation. To gauge degree of certainty, surgeons in-
dicated how condent they were in their estimation for
each disease. Finally, we sought to identify the number of
cases that can be reasonably performed each year by the
average practicing neurosurgeon. Surgeons indicated their
annual case volume and types of cases most frequently

J Neurosurg April 27, 2018 3
M. C. Dewan et al.
performed, then indicated how they perceived their work-
load at that clinical volume. The full questionnaire and
analytical methodology are described in detail elsewhere.5
Neurosurgical Workforce
Determination of the current neurosurgical workforce
was quantied via a large, multinational global mapping
project facilitated by the World Federation of Neurosur-
gical Societies (WFNS), the WHO, and the Program in
Global Surgery and Social Change (PGSSC) at Harvard
Medical School. Briey, Ministries of Health, ofcers of
the 130 societies registered with the WF NS, and the mem-
bers of the WHO Global Initiative for Emergency and
Essential Care were contacted via email for information.
For some countries an internet search was conducted to
identify the contact information for active neurosurgeons
willing and able to complete an online questionnaire on
capacity. Surgeons registered with the open access Glob-
al Neurosurgery forum (https://globalneurosurgery.org/
members) were also included. The data collection instru-
ment captured surgeon numbers and geographic locations,
as well as the presence of basic equipment germane to
neurosurgical care: high-speed drills, bipolar electrocau-
tery, imaging infrastructure, etc. For the purposes of the
current summary, we aggregated the number of neurosur-
geons by country and by WHO region to facilitate quanti-
cation of the current surgical capacity. A comprehensive
description of the methodology and results of the PGSSC
workforce mapping initiative is described elsewhere (un-
published data).14
Estimating the Decit in Neurosurgical Care
The unmet need, or decit in neurosurgical care, repre-
sents the difference between the total estimated number of
essential neurosurgical conditions presenting for treatment
and the current number of neurosurgical cases that can be
performed given the existing workforce. The number of
essential neurosurgical conditions was calculated by tak-
ing the product of neurosurgical volume (from each meta-
analysis by disease entity3,7–9,11,16,19) and surgical proportion
(from the provider survey5). The number of neurosurgical
cases that can be currently performed, on the other hand,
was obtained by taking the product of the number of neu-
rosurgeons (from the Workforce estimate [unpublished
data]) and the median number of cases performed (from
the provider survey estimate5). The decit was then cal-
culated on a regional and income-group basis to provide
a more granular description of need and volume, and to
highlight disparity in neurosurgical care across regions.
Then, a country-specic ratio of neurosurgeons to essen-
tial neurosurgical cases (both surgical and consultative)
was estimated. The total number of cases within a region
was allocated to each country according to the population
proportion of a given country within its WHO region and
World Bank income group. For the worldwide estimate,
all countries with available workforce data were included,
irrespective of WHO or World Bank classication. Incor-
porating the country-specic neurosurgeon gure from
the workforce survey, maps were then created to depict
this ratio using Tableau software.
Results
Estimations of the volume of each disease, the propor-
tion requiring neurosurgical intervention, and the quanti-
cation of the existing neurosurgical workforce have been
described in detail elsewhere. Here, we have aggregated
this information and synthesized the ndings into a di-
gestible summary.
Neurosurgical Cases by Region and Income Group
An estimated 13.8 million essential neurosurgical cas-
es develop each year, of which more than 80% arise in
low- and middle-income countries (Table 1). A detailed
breakdown of neurosurgical volume by disease can be
found in the Appendix (Tables S1–S23). Corresponding
to the regional population proportions, an expected 3.5
million and 3.7 million new cases are expected in South-
east Asia and the Western Pacic, respectively. Africa is
expected to endure nearly 2 million neurosurgical cases,
in contrast to about 665,000 cases in the US and Canada.
Europe, the Eastern Mediterranean, and Latin America
each will encounter between 1.1 and 1.8 million new neu-
rosurgical cases annually (Table 1). Among the conditions
we have dened as requiring essential neurosurgical care,
surgery for TBI (burr holes, craniotomy/craniectomy, etc.)
accounts for 45%, cerebrovascular accident for 20%, hy-
drocephalus for 7%, and brain tumors for 5%. Vascular
anomalies (2.2%), neural tube defects (0.3%), and spinal
tumors (0.1%) occupy a relatively modest proportion of the
global neurosurgical need.
The number of cases requiring neurosurgical consul-
tation—but not necessarily surgical intervention—is far
greater, approaching 22.6 million annually (Table 2).
Again, Southeast Asia and the Western Pacic bear the
greatest consultative demand with 5.8 million and 6.2 mil-
lion cases each year, respectively. Low and middle-income
countries (LMIC) endure the greatest burden at 17.6 mil-
lion cases, compared with 4.3 million cases in high-in-
come countries (HIC).
Neurosurgeons by Region and Income Group
We identied 49,940 practicing neurosurgeons world-
wide (unpublished data). Ninety-eight percent (98.9%) of
neurosurgeons were identied via the WFNS-sponsored
electronic survey, while 560 neurosurgeons (1.1%) from
34 countries (14.9%) in which no data were available were
imputed via statistical modeling. The greatest population
of neurosurgeons resides in the Western Pacic region,
with China and Japan alone accounting for more than
18,000 neurosurgeons. Europe and the US/Canada have
the next largest populations of neurosurgeons, with 10,719
and 5296 neurosurgeons, respectively. In the African re-
gion, with a population of 990 million, 488 neurosurgeons
were identied (Table 3). Forty-four percent (44%) of neu-
rosurgeons worldwide reside in high-income countries.
Previously, we have identied the mean neurosurgical
volume reasonably managed by a neurosurgeon in a given
country as 223 cases per year.5 This assumes a surgeon’s
perceived workload is maintained at a level of 75 out of
100 (where 0 is “not at all busy” and 100 is “extremely
busy, overworked”). The greatest total neurosurgical ca-

M. C. Dewan et al.
J Neurosurg April 27, 20184
TABLE 1. Estimated number of cases requiring neurosurgical operation, by WHO region and income group
WHO Region Brain Tumor Spinal Tumor TBI TSI Stroke HC NTD Vascular Anomalies Infection Epilepsy Total (95% CI)
AFR 63,343 1032 708,181 70,032 239,675 420,674 22,942 23,564 241,910 195,039 1,986,392 (377,966–3,564,330)
AMR-L 77,293 1317 514,592 41,294 103,362 123,924 3993 18,088 103,267 159,042 1,146,170 (657,411–1, 578,720)
AMR-US/Can 56,742 1848 414,171 9474 71,290 33,564 1250 13,515 2955 59,888 664,698 (247,052–906,397)
EMR 53,927 1673 518,981 17,523 178,223 89,168 4708 2799 32,649 157,363 1,057,015 (688,679–1,377,989)
EUR 148,819 3819 828,173 16,169 493,511 94,910 1949 47,473 25,494 96,575 1,756,891 (1,175,365–2,292,342)
SEAR 147,501 1044 1,631,484 137,389 657,300 124,708 10,394 29,657 446,085 319,221 3,504,783 (1,059,489–5,775,574)
WPR 187,524 7109 1,545,233 119,280 1,031,871 84,369 6864 145,684 116,641 426,298 3,670,873 (1,339,219–5,850,732)
HIC 181,465 5479 1,597,979 52,768 352,852 29,858 31,928 62,946 26,114 141,086 2,482,475 (871,290–3,414,859)
LMIC 720,074 16,666 4,458,615 438,524 2,407,551 740,305 3695 95,863 701,188 1,166,036 10,748,517 (4,601,979–15,505,041)
Global 735,180 17,840 6,160,814 399,606 2,760,403 971,317 35,622 311,407 969,001 1,413,426 13,786,823 (6,245,611–20,645,656)
AFR = Afric an Region; AMR-L = Region of the Americas (Latina America); AMR-US/Can = Region of the Americas (US and Canada); CI = condence interval; EMR = Eastern Mediterranean Region; EUR = European
Region; HC = hydrocephalus; NTD = neural tube defect; SEAR = Southeast Asia Region; WPR = Western Pacic Region.
TABLE 2. Estimated number of cases requiring neurosurgical consultation, by WHO region and income group
WHO Region Brain Tumor Spinal Tumor TBI TSI Stroke HC NTD Vascular Anomalies Infection Epilepsy Total (95% CI)
AFR 77,961 1195 1,265,685 113,128 417,498 449,356 25,740 33,994 318,882 325,065 3,028,504 (963,498–5,039,023)
AMR-L 95,129 1526 919,696 66,706 180,051 132,373 4479 26,094 136,124 265,070 1,827,247 (1,119,077–2,434,959)
AMR-US/Can 69,836 2141 740,221 15,305 124,183 35,853 1402 19,496 3896 99,813 1,112,147 (410,79–1,499,044)
EMR 66,372 1938 927,540 28,307 310,453 95,248 5283 4038 43,038 262,272 1,744,489 (1,159,625 –2,244,705)
EUR 183,162 4424 1,480,138 26,119 859,664 101,381 2187 68,486 33,605 160,958 2,920,125 (1,990,180–3,767,722)
SEAR 181,540 1209 2,915,844 221,936 1,144,975 133,211 11,662 42,784 588,021 532,035 5,773,216 (2,489,612–8,744,941)
WPR 230,799 8236 2,761,693 192,683 1,797,452 90,121 7701 210,168 153,754 710,497 6,163,104 (3,004,300–9,050,615)
HIC 223,341 6348 2,855,963 85,241 614,645 81,445 35,821 90,807 34,423 235,144 4,263,178 (1,506,562–5,707,516)
LMIC 886,245 19,308 7,968,589 708,385 4,193,799 790,780 4146 138,294 924,293 1,943,394 17, 577,232 (8,617,552–24,0 52, 631)
Global 904,836 20,668 11,010,817 645,517 4,808,444 1,037,543 39,967 449,244 1,277,320 2,355,710 22,568,833 (12,167,919–31,750,174)

J Neurosurg April 27, 2018 5
M. C. Dewan et al.
pacity exists in the Western Pacic region, where more
than 22,000 neurosurgeons are capable of performing
nearly 5 million essential neurosurgical cases annually. In
contrast, the nearly 500 neurosurgeons in Africa can be
expected to perform approximately 110,000 neurosurgical
operations. Worldwide, and ignoring geographic boundar-
ies and uneven case distribution, the overall surgical ca-
pacity is approximately 11 million essential neurosurgical
cases per year (Table 3).
The Decit in Neurosurgical Care
The current decit in neurosurgical care is approxi-
mately 5.2 million (Table 3). This decit derives from
the difference between the number of essential cases en-
countered annually and the essential surgical capacity,
where essential surgical capacity excludes nonessential
cases performed by neurosurgeons, particularly in HIC.
To meet this demand, an estimated additional 22,626
neurosurgeons would need to be trained. The greatest
decit resides in Southeast Asia where nearly 2.5 million
essential cases go unmet. The tremendous shortage of
neurosurgeons in India—where 3500 neurosurgeons are
responsible for a population of more than 1.2 billion—is
largely responsible for this health care discrepancy. For
the entire region, 2.5-times the existing number of sur-
geons are needed to provide appropriate coverage. In Af-
rica, where more than 1.8 million cases are not being ad-
dressed by capable neurosurgeons, the surgical workforce
must increase by more than 1700% to meet the regional
demand. The vast majority of the population in Africa has
no access to a neurosurgeon, independent of other geo-
graphic, social, or nancial barriers that may exist.14 In
terms of essential care, three WHO regions—the region
of the Americas restricted to the US and Canada only, the
European region, and the Western Pacic region—do not
demonstrate a workforce decit, although the need for ad-
ditional neurosurgeons in these regions to meet neurologi-
cal conditions not accounted for in our analysis remains a
salient consideration.
Discussion
In this summary, for neurosurgical diseases, we es-
timate approximately 13.8 million new operative cases
and 22.6 million new consultative cases exist worldwide
each year. TBI and stroke-related conditions and sequelae
constitute approximately 60% of essential neurosurgi-
cal volume, with tumors, hydrocephalus, epilepsy, and
infectious-related conditions accounting for the majority
of the remaining proportion of disease. A tremendous dis-
parity exists in the global workforce; 82% of neurosurgi-
cal volume exists in LMICs where approximately 56% of
neurosurgeons reside. While Africa accounts for 15% of
the global volume of neurosurgical disease, African hos-
pitals and health care networks have access to less than
1% of the neurosurgeon community. An estimated 23,300
additional surgeons—approximately 11,300 in Southeast
Asia, and 8400 in Africa—are needed in low- and middle-
income countries to adequately address essential neuro-
surgical disease worldwide. For the rst time, an estimate
of the decit of neurosurgical care is provided. The world
maps (Figs. 1 and 2) offer a pictorial representation of the
volume of essential neurosurgical disease observed by
the existing neurosurgical workforce in a given country;
disparity in care is illustrated. Training capable and com-
petent neurosurgeons is a fundamental step in establish-
ing equal access to safe and timely neurosurgical care. A
benchmark is thus established for which to aim.
Examining Tables 1 and 2 more closely, there are 3 im-
portant observations that merit specic discussion. First,
these disease gures are estimates. While they derive from
the best available evidence and are computed using modern
statistical modeling, they remain susceptible to the same
methodological assumptions made for any epidemiologi-
cal estimation of disease incidence. Second, we notice that
diseases requiring advanced diagnostic equipment for di-
agnosis (e.g., MRI) are more likely to be underrepresented
in regions made up of predominantly low income or lower
middle income countries. CNS tumors are taken as an ex-
ample. There exists a positive correlation between age and
incidence of brain tumors. Most populations in HICs ex-
hibit a greater median survival than those in LMICs. Thus,
ignoring competing variables (such as carcinogenic expo-
sures, or prevention of metastatic spread) nding a higher
proportion of brain tumors in the US/Canadian region
than in African region follows logic. However, the degree
to which this difference exists suggests additional factors
are involved. For these less clinically overt diseases, a di-
agnosis bias almost certainly affects these results. Brain
and spinal tumors in low-resource settings are not being
TABLE 3. Summary of case volume, surgical capacity, and neurosurgical decit
WHO Region Case Volume Current Surgeons Case Capacity Case Decit* Additional Surgeons Necessary*
AFR 1,986,392 488 108,824 1,877,568 8420
AMR-L 1,146,170 4216 940,168 206,002 924
AMR-US/Can 664,698 5296 1,181,008 — —
EMR 1,057,015 2073 462,279 594,736 2667
EUR 1,756,891 10,719 2,390,337 — —
SEAR 3,504,783 4409 983,207 2,521,576 11,308
WPR 3,670,873 22,114 4,931,422 — —
Worldwide 13,786,823 49,940 11,136,620 5,199,883 23,318
* “Case Decit” and “Additional Surgeons Necessar y” are left blank for regions that have a capacity surplus. Capacity surplus suggests cases are being per formed by
neurosurgeons that fall outside of the denition of “essential neurosurgical care,” such as degenerative spine disease and movement disorders.

M. C. Dewan et al.
J Neurosurg April 27, 20186
diagnosed due to lack of equipment and/or lack of access
to the level of care requisite for their diagnosis. Converse-
ly, readily diagnosed diseases such as neural tube defects
are more likely to be captured by population-based epide-
miological studies, regardless of diagnostic infrastructure.
Third, while the estimates are staggering—especially in
relation to the existing workforce—they are most certainly
an underestimate of the true surgical responsibilities faced
by the global neurosurgery community. Absent from these
estimates are entities such as diagnostic procedures (lum-
bar punctures, ventricular taps, etc.), repeat or redo surger-
ies, and, importantly, the great proportion of neurosurgical
interventions that are deemed “nonessential” by the out-
lined criteria.
This year, nearly 5.2 million essential neurosurgical cas-
es are estimated to go unmet by a qualied neurosurgeon,
resulting in otherwise avoidable disability and death. Such
essential neurosurgical cases include relatively straightfor-
ward procedures such as burr hole craniotomy for hema-
toma evacuation and shunt insertion for childhood hydro-
cephalus. Interestingly, these are the only two surgeries
mentioned in the 44 essential surgical procedures listed
within the Disease Control Priorities series published by
the World Bank Group.4 However, extraaxial hemorrhage
and hydrocephalus represent only a small fraction of neu-
rosurgical conditions that result in severe disability and
death if left untreated. Essential operations as outlined in
this report also include brain tumor resection, cerebral an-
eurysm exclusion, and open spinal fracture reduction and
xation, all considered to require more advanced surgi-
cal technique and resources. Designating treatment tiers to
balance access to care and quality of delivery is imperative
to optimize geographic coverage. While a discussion of
this concept reaches beyond the scope of this summary,
the centralization of highly complex neurosurgical care—
while also prioritizing basic, emergency neurosurgical
care peripherally—is an important model that must remain
a priority for the global neurosurgery community, espe-
cially in LMICs.
Ongoing Efforts to Increase Neurosurgical Capacity
A number of efforts to increase neurosurgical capac-
ity in LMICs have already begun to make a difference.
Enabling nonneurosurgeons to perform neurosurgical in-
terventions (task-shifting) that are technically straightfor-
ward and have a high benet to risk ratio (such as emer-
gency evacuation of an epidural hematoma) is rational.
Likewise, teaching nonneurosurgeons to place shunts for
hydrocephalus has been advocated by some, but infant hy-
drocephalus is not immediately life-threatening; although
placing the initial shunt is not difcult, the signicant
complication rate requires timely neurosurgical expertise
for subsequent management. The ultimate goal should be
FIG. 1. The global decit of neurosurgical care: operations. ©OpenStreetMap contributors (http://www.openstreetmap.org/
copyright). Figure is available in color online only.

J Neurosurg April 27, 2018 7
M. C. Dewan et al.
to increase neurosurgical capacity by increasing the num-
ber of competent and accessible neurosurgeons in under-
served regions. The most sustainable way to achieve this
will be for adequately trained national neurosurgeons to
begin training programs in their home countries. This may
initially require the importation of expertise, but the need
for this would diminish over time if an investment is made
in training individuals from these countries.
The global neurosurgery community should prioritize
the provision of training to individuals from countries that
do not have adequate neurosurgery residency programs.
Historically, people who leave home to train in a high-in-
come country often fail to return. But in the past decade,
sub-Saharan Africa has benetted from an inux of neu-
rosurgeons because the few established training programs
on the continent have embraced the opportunity to incor-
porate trainees from the less developed countries into their
residency programs. Programs in Morocco, Senegal, Zim-
babwe, and South Africa have trained approximately 60
new neurosurgeons from other African countries thus far.
Also, a new East African training program has recently
been established in cooperation with The College of Sur-
geons of East Central and Southern Africa, with training
sites in Tanzania, Uganda, and Kenya. All these programs
provide more appropriately contextualized training in re-
gard to pathology and resource availability, and are more
likely to see their trainees return home to build neurosurgi-
cal capacity in their own countries. In addition, longitudi-
nal partnerships between centers in LMICs and academic
neurosurgery departments in HICs (Duke University, Uni-
versity of Alabama, University of Miami, The University
of Toronto, The Weill Cornell Medical College, The Bar-
row Neurological Institute, and others) are fostering con-
tinued training, mentoring, and collaborative research in
sub-Saharan Africa, Southeast Asia, and Latin America.
Other programs, such as CURE Hydrocephalus and Spina
Bida, provide subspecialty training fellowships to neuro-
surgeons from across the developing world. Furthermore,
organized neurosurgery (such as the Foundation for Inter-
national Education in Neurosurgery, the WFNS, the Asian
Australasian Society of Neurological Surgeons, the Amer-
ican Association of Neurological Surgeons, the European
Society of Pediatric Neurosurgery, and the International
Society of Pediatric Neurosurgery) has long been engaged
in international neurosurgery education. The past 10 years
have seen a noticeable escalation in awareness of and com-
mitment to global neurosurgery that should, if we stay on
mission, gradually improve access to neurosurgical care
for people everywhere.
The Way Forward
The Role of Professional/National Societies
National neurosurgical societies exist to represent their
FIG. 2. The global decit of neurosurgical care: consultations. ©OpenStreetMap contributors (http://www.openstreetmap.org/
copyright). Figure is available in color online only.

M. C. Dewan et al.
J Neurosurg April 27, 20188
community of neurosurgeons via surgical education, the
promotion of scientic exchange, establishment of prac-
tice guidelines, and at times the promotion of a legislative
agenda. For an individual surgeon, particularly one who
operates in a solo practice, the national society serves as
the most direct conduit to peer evaluation and feedback,
continuing surgical education, and surgeon fellowship. A
robust and active professional society serves to enhance
the quality of neurosurgical care delivery by its member-
ship. Thus, as the global neurosurgery effort matures, pro-
fessional societies are a natural springboard from which
to launch targeted intervention strategies, and may have
broader impact than simply targeting a specic hospital,
university, or institution.
Naturally, a professional society’s role depends upon
the resources and capabilities that exist on the ground. For
example, in low-resource settings, high-priority initiatives
of a neurosurgical society may include surveying region-
al disease burden, organizing available manpower, and
lobbying for federal support. Meanwhile, societies in re-
source-rich countries can invite meaningful participation
from LMIC surgeons, organize a workforce of members
interested in cross-national education and training, and
allocate activities, meetings, and funding to international
education and research initiatives. Indeed, some societies
in HICs are already playing an active role by doing just
this. Throughout, developing and fostering a relationship
between societies built upon respect and mutual benet
is essential to ensuring productive and sustainable cross-
collaborations.
The Role of Global Governance
The WFNS is a professional, nongovernmental organi-
zation representing 118 individual societies of neurosur-
gery worldwide. With the overarching purpose to promote
global improvement in neurosurgical care, capacity build-
ing through education and surgeon training is among the
dening principles of the Federation. For example, as the
glaring shortage of neurosurgeons in Africa has grown,
the WFNS has taken specic actions such as facilitation
of the “Africa 100” initiative championed by Professor
Majid Samii and designed to increase the number of per-
manent practicing surgeons on the continent. Via such ini-
tiatives, the Federation can work to establish educational
paradigms that incorporate open-access, web-based edu-
cational platforms accessible to trainees and consultants
from all corners of the globe. Indeed, the WFNS already
has a track record as a central, nonpartisan organization
for open collaboration between member partners and the
transfer of ideas and technologies across the many na-
tional societies. Moving forward, the WFNS is optimally
suited for advocacy toward and coordination of the neu-
rosurgery capacity building effort. In so doing, the Fed-
eration is well positioned to: 1) raise awareness of the un-
met neurosurgical care as a global public health issue; 2)
develop educational and practice guidelines based upon
member input; 3) collect and monitor global neurosurgical
workforce and capacity data; and 4) facilitate coordination
and collaboration between the academic community and
state-sponsored agencies toward efciently addressing the
worldwide decit in neurosurgical care.
Integrating Neurosurgery Within the Overall Surgical Community
Neurosurgical efforts aimed at LMICs would ben-
et greatly from integration with ongoing global surgical
programs through partnerships with professional societ-
ies, academia, and nongovernmental organizations, to
avoid duplication and to complement the surgical sys-
tem–strengthening efforts of each stakeholder. In many
regions, there already exist efforts designed to develop or
improve surgical and anesthesia service delivery, enhanc-
ing the overall surgical ecosystem. Consider, for example,
the essential nature of a blood bank for safe surgical care:
it matters little if packed red blood cells are used for a
postpartum hemorrhage, a malaria crisis, or a severe TBI.
Surgeons of all types and anesthetists can work together
synergistically to develop and maintain components of the
entire surgical delivery system. Partnership with United
Nations bodies, such as the WHO, provide collaborative
arrangements with local governments that offer the ad-
vantage of enhancing service delivery mechanisms in-
country. The WHO, through the Emergency and Essential
Surgical Care Program, is poised to facilitate global coor-
dination of neurosurgical efforts along with other surgical
stakeholders as dened by the mandates of member states.
Currently, combined efforts targeting advocacy, ser-
vice delivery, data collection, essential medicines, and
health workforce are critical, thus fullling the mandates
of World Health Assembly Resolution 68.15 (2015) on
strengthening emergency and essential surgical care and
anesthesia as a component of universal health coverage,7
all with direct links to the sustainable development goals.18
Strengths and Limitations of the Study
The estimates and conclusions outlined in this sum-
mary must be considered in the context of several limi-
tations. First, most disease volume gures derive from
large systematic reviews and meta-analyses, as reliable,
population-based estimates for each country or region
are nonexistent. Similarly, the surgical workforce gures
relied upon accurate neurosurgical association reporting,
and at times questionnaire responses and statistical mod-
eling, all of which carry bias and intrinsic inconsistencies.
Throughout the tables and text, we assume that neurosur-
geons are optimally distributed geographically in relation
to the at-risk population. We also assume that each trained
neurosurgeon is capable of safely treating each condition
encompassed within the designation of essential neurosur-
gical care. While these assumptions are generally safe for
epidemiological modeling at the region- or country-level,
they would not permit accurate allocation of resources at
the city or hospital level. In relation to surgical capacity,
we have focused on the surgeon only—not the wealth of
infrastructure, equipment, and personnel required along-
side the surgeon to facilitate safe and timely provision of
neurosurgical care. We acknowledge the tremendous im-
portance of these resources, and we are actively conduct-
ing a worldwide survey to better understand their acces-
sibility to current and future surgeons.14
In an effort to prioritize the most life-threatening neu-
rosurgical conditions worldwide, we have deliberately ex-
cluded many important conditions commonly addressed
by neurosurgeons, most notably degenerative spine dis-

J Neurosurg April 27, 2018 9
M. C. Dewan et al.
ease. This relative limitation warrants specic elabora-
tion. In the US, with more than 5000 neurosurgeons, we
estimate the case capacity is nearly 1.2 million cases/year.
Meanwhile, the volume of essential neurosurgical cases is
estimated at only 576,000, suggesting a surplus of neuro-
surgeons exists in the US. We would caution the reader
against this conclusion. The majority of neurosurgical cas-
es performed in the US are for conditions falling outside
the designation used in this report of essential neurosurgi-
cal care. Indeed, entities like degenerative spine disease,
chronic pain, movement disorders, and many other con-
ditions are well known to cause disability and suffering
if left untreated. Thus, a shortage of neurosurgeons may
exist even in the most developed of countries, depending
upon the level and type of neurosurgical care demanded
by a given population. The scope and purpose of this pa-
per is to offer a description of the workforce capacity and
decit that exists for essential neurosurgical care, a des-
ignation that itself aims to prioritize those patients who
are most likely to benet from lifesaving and disability-
averting neurosurgical care.
Finally, this report ignores the concept of task sharing
and the number of procedures potentially performed by
nonneurosurgeon providers. Training general surgeons
in common neurosurgical procedures such as ventriculo-
peritoneal shunt insertion and burr hole craniotomy is a
practical strategy that might more quickly help curb the
overwhelming neurosurgical burden. Reasonable neuro-
surgical experts will disagree on the ethics and quality-
related implications of this frequently used strategy in the
realm of global health. The potential capacity-related con-
sequences of this strategy, however, are absent from the
gures provided above.
While inherent limitations exist for an epidemiological
survey and capacity estimation of this scope, careful and
deliberate measures were taken to ensure data validity and
provide methodological transparency throughout. Rather
than relying on surgical log data from hospitals and health
systems where the surgical care is known to be inadequate,
we approached surgical decit gures rst from the disease
component of the equation. Though data modeling was
necessary in some cases, the disease-specic estimates
represent the best available evidence to date, derived from
among the most comprehensive systematic reviews avail-
able in the neurosurgical literature. Additionally, surgical
provider data arose from the most far-reaching effort yet to
quantify the worldwide population of neurosurgeons, and
involved a partnering effort with many active international
neurosurgery initiatives such as the WFNS.
Conclusions
Each year, 13.8 million new essential neurosurgical
operative cases and 22.6 million new consultative cases
present worldwide. TBI, tumor, hydrocephalus, and stroke-
related conditions constitute the majority of essential neu-
rosurgical volume globally. Regional variation in disease
incidence is likely inuenced by a host of factors includi ng
baseline population demographics, risk factor exposure,
and genetic susceptibility. Wide workforce gaps exist,
and the uneven distribution of neurosurgeons to disease
volume creates large geographic pockets of surgical ac-
cess shortage. Nearly 23,000 additional neurosurgeons are
needed in low- and middle-income countries to adequately
address the unmet decit of more than 5 million neurosur-
gical operations worldwide.
Acknowledgments
We would like to thank Ron Baticulon, MD, for his graphical
expertise. The work in this report was enhanced by the logistical,
financial, or in-kind support that we received from the following
organizations: Boston Children’s Hospital Global Hydrocephalus
and Spina Bifida Fund, Harvard Medical School Department of
Global Health and Social Medicine, John D. and Catherine T.
MacArthur Foundation, Kellogg Institute for International Stud-
ies at the University of Notre Dame, Vanderbilt Medical Scholars
Program, Vanderbilt University Medical Center, and the WFNS.
Appendix
Collaborators
We would like to thank the following individuals for their
dedication and contribution to identifying the global neurosurgical
deficit. Collaborators are listed in alphabetical order:
Amos O. Adeleye, MBBS, Amit Agrawal, MCh, Blake C.
Alkire, MD, MPH, Julia R. Amundson, BS, Hildo Azevedo-Filho,
MD, PhD, Ronnie E. Baticulon, MD, Joseph S. Bell, PhD, Erica
Bisson, MD, MPH, Kamila M. Bond, BA, Vivek P. Buch, MD, Mat-
thew C. Davis, MD, Robert Dempsey, MD, Serena Faruque, MS,
PhD, Laurence Glancz, MBBS, BSc, William B. Gormley, MD,
MPH, MBA, Saksham Gupta, BA, Michael M. Haglund, MD, PhD,
MACM, Roger Härtl, MD, Joshua D. Hughes, MD, Ya Ching Hung,
MD, Yoko Kato, MD, PhD, Robert M. Koffie, MD, PhD, Ramesh
Kumar, MD, Jacob R. Lepard, MD, Jaims Lim, BS, Muhammad
Raji Mahmud, MD, John G. Meara, MD, DMD, MBA, Rania A.
Mekary, MSc, PhD, Basant K Misra, MD, Jacques J. Morcos, MD,
Swagoto Mukhopadhyay, MD, Brian V. Nahed, MD, MSc, Enrique
Osorio-Fonseca, MD, Sophie Peeters, BS, Maria Punchak, MSc,
Mahmood M. Qureshi, MD, Christian Lopez Ramos, BS, Vijay
Ravindra, MD, MSPH, Faith C. Robertson, BS, Jeffrey V. Rosen-
feld, MD, Gail Rosseau, MD, Andrés M. Rubiano, MD, Sonal
Sachdev, MD, Steven S. Senglaub, MS, Salman Y. Sharif, MD,
Mark G. Shrime, MD, MPH, PhD, Kerry A. Vaughan, MD, Eka J.
Wahjoepramono, MD, PhD, John C. Wellons III, MD, MSPH, and
Ismaeel Yunusa, PharmD.
References
1. Albright AL: Reections on developing pediatric neurosur-
gery in Sub-Saharan Africa. J Neurosurg Pediatr 18:127–
138, 2016
2. Andrews RJ, Quintana LM: Neurosurgical care for one—
neurosurgical care for all: global neurosurgical care has
global benets! World Neurosurg 85:22–24, 2016
3. Bell JS, Kofe R, Rattani A, Dewan MC, Baticulon R,
Qureshi M, et al: Global incidence of brain and spinal
tumors by geographic region and income level, presented at
the Congress of Neurological Surgeons Annual Meeting,
Boston, 2017 (Poster) (http://2017.cns.org/posterbrowser.aspx)
[Accessed April 16, 2018]
4. Debas HT, Donkor P, Gawande AA, Kruk M, Jamison DT,
Mock C, et al: Disease Control Priorities: Essential Sur-
gery, ed 3. Washington, DC: World Bank Publications, 2015
5. Dewan MC, Rattani A, Baticulon RE, Faruque S, Johnson
WD, Dempsey RJ, et al: The operative proportion of neuro-
surgical disease worldwide: an estimation from the surgeon
perspective. J Neurosurg [in press], 2018
6. Dewan MC, Rattani A, Gupta S, Baticulon RE, Hung YC,

M. C. Dewan et al.
J Neurosurg April 27, 201810
Punchak M, et al: Estimating the global incidence of trau-
matic brain injury. J Neurosurg [in press], 2018
7. Dewan MC, Rattani A, Mekary RA, Glancz LJ, Yunusa I,
Baticulon RE, et al: Global hydrocephalus epidemiology and
incidence: systematic review and meta-analysis. J Neurosurg
[in press], 2018
8. Hughes JD, Bond KM, Mekary RA, Dewan MC, Rattani A,
Kato Y, et al: A systematic literature review for the global
incidence of central nervous system vascular lesions and
meta-analysis of hemorrhagic aneurysms, arteriovenous
malformations, and dural arteriovenous stulas, presented at
the Congress of Neurological Surgeons Annual Meeting,
Boston, 2017 (Poster) (http://2017.cns.org/posterbrowser.aspx)
[Accessed January 12, 2018]
9. Hughes JD, Bond K, Mekary R, Dewan MC, Rattani A, Kato
Y, et al: Estimating the global incidence of central nervous
system vascular lesions: a systematic review and meta-analy-
sis of aneurysmal subarachnoid hemorrhage. World Neuro-
surg [in press], 2018
10. Kancherla V, Walani SR, Weakland AP, Bauwens L, Oakley
GP Jr, Warf BC: Scorecard for spina bida research, preven-
tion, and policy – a development process. Prev Med 99:13–
20, 2017
11. Kumar R, Lim J, Mekary RA, Rattani A, Dewan MC, Sharif
SY, et al: Traumatic spinal injury: global epidemiology and
worldwide volume. World Neurosurg [epub ahead of print],
2018
12. Meara JG, Leather AJM, Hagander L, Alkire BC, Alonso N,
Ameh EA, et al: Global Surgery 2030: evidence and solutions
for achieving health, welfare, and economic development.
Lancet 386:569–624, 2015
13. Park KB, Johnson WD, Dempsey RJ: Global neurosurgery:
the unmet need. World Neurosurg 88:32–35, 2016
14. Punchak M, Mukhopadhyay S, Sachdev S, Hung YC, Peeters
S, Rattani A, et al: Neurosurgical care: availability and ac-
cess in low-income and middle-income countries. World
Neurosurg 112:e240–e254, 2018
15. Ravindra V, Senglaub S, Rattani A, Park KB, Dewan MC,
Shrime MG: Degenerative lumbar spine disease: estimating
global incidence and worldwide volume. Global Spine J [in
press], 2018
16. Robertson FC, Lepard JR, Davis MC, Mekary R, Yunusa I,
Dewan MC, et al: Epidemiology of CNS infectious disease: a
meta-analysis and implications for the global neurosurgeon. J
Neurosurg [in press], 2018
17. Shrime MG, Bickler SW, Alkire BC, Mock C: Global burden
of surgical disease: an estimation from the provider perspec-
tive. Lancet Glob Health 3 (Suppl 2):S8–S9, 2015
18. United Nations: Transforming Our World: the
2030 Agenda for Sustainable Development.
(https://sustainabledevelopment.un.org/post2015/
transformingourworld) [Accessed January 12, 2018].
19. Vaughan KA, Ramos CL, Buch VP, Mekary R, Amundson
JR, Shah M, et al: An estimation of global volume of surgi-
cally treatable epilepsy based on a systematic review and
meta-analysis of epilepsy. J Neurosurg [in press], 2018
20. Warf BC: “Who is my neighbor?” Global neurosurgery in a
non-zero-sum world. World Neurosurg 84:1547–1549, 2015
21. World Health Organization: World Health Assembly resolu-
tion 68.15: Strengthening emergency and essential surgical
care and anaesthesia as a component of universal health
coverage. (http://apps.who.int/gb/ebwha/pdf_les/WHA68/
A68_R15-en.pdf) [Accessed January 12, 2018]
Disclosures
The authors report no conflict of interest concerning the materi-
als or methods used in this study or the findings specified in this
paper.
Author Contributions
Conception and design: Dewan. Acquisition of data: Dewan, Rat-
tani. Analysis and interpretation of data: Dewan, Rattani, Fieggen,
Arraez, Servadei, Johnson, Warf. Drafting the article: Dewan,
Fieggen, Arraez, Servadei, Boop, Johnson, Warf. Critically revis-
ing the article: all authors. Reviewed submitted version of manu-
script: all authors. Approved the final version of the manuscript
on behalf of all authors: Dewan. Statistical analysis: Rattani.
Administrative/technical/material support: Rattani.
Supplemental Information
Online-Only Content
Supplemental material is available with the online version of the
article.
Appendix. https://thejns.org/doi/suppl/10.3171/2017.11.
JNS171500.
Correspondence
Michael C. Dewan: Vanderbilt University Medical Center, Nash-
ville, TN. dewan.michael@gmail.com.