Available via license: CC BY 4.0
Content may be subject to copyright.
Advances in Parkinson’s Disease, 2017, 6, 86-92
http://www.scirp.org/journal/apd
ISSN Online: 2169-9720
ISSN Print: 2169-9712
DOI:
10.4236/apd.2017.63009 Aug. 17, 2017 86 Advances in Parkinson’s Disease
Racial Demographics in an Urban Movement
Disorders Clinic
Chantale O. Branson1, Luke Quehl2, Raymond James1, Janice Weinberg3, Anna D. Hohler1,
Marie-Helene Saint-Hilaire1
1Department of Neurology, Boston University Medical Center, Boston, MA, USA
2Boston University School of Medicine, Boston, MA, USA
3Boston University School of Public Health, Boston, MA, USA
Abstract
Objective:
To assess the prevalence of Parkinson’s disease (PD) among Afr
i-
can-Americans compared to non-Hispanic Whites in a tertiary urban Mov
e-
ment Disorders center.
Background: Contributing factors in the prevalence of
Parkinson’s disease (PD) based on race may improve health disparities in the
United States. According to the largest study analyzing prevalence and inc
i-
dence of PD among Medicare beneficiaries, the ratio of African-
Americans
(AA) to Caucasians in the general Medicare population is 9%, while the pr
e-
valence ratio of PD among AA compared to Caucasians is approximate
ly 5%.
Methods:
We performed a retrospective analysis of African-American p
a-
tients with PD in the movement disorders database at Boston Medical Center,
which is the largest safety net hospital in New England.
The demographics of
the patients seen in the ge
neral neurology clinic are 30.57% AA and 38.06%
non-Hispanic Caucasian.
Results:
The Movement disorders database inclu
-
ded 488 patients, 327 of whom had PD. Of these, 287 were Caucasians and 18
were of African descent. Based on our clinic population the e
xpected PD case
ratio among AA compared to Caucasians was approximately 49%. The actual
race ratio in patients of African descent compared to Caucasian was 6%,
which was substantially lower than expected at Boston Medical Center.
Con-
clusion:
The demographi
cs of the PD patients in our movement disorders
clinic do not reflect the population at Boston Medical Center, or the dem
o-
graphics of our neurology clinic as a whole.
Keywords
Racial Demographics, Urban Movement Disorders Clinic
How to cite this paper:
Branson, C.O.,
Quehl, L
., James, R., Weinberg, J.,
Hohler,
A
.D. and Saint-Hilaire, M.-H. (2017)
Racial
Demographics in an Urban Movement Dis
-
orders Clinic
.
Advances in Parkinson’s Dis
-
ease
,
6
, 86-92.
https://doi.org/10.4236/apd.2017.63009
Received:
July 12, 2017
Accepted:
August 14, 2017
Published:
August 17, 2017
Copyright © 201
7 by authors and
Scientific
Research Publishing Inc.
This work is licensed under the Creative
Commons Attribution
International
License (CC BY
4.0).
http://creativecommons.org/licenses/by/4.0/
Open Access
C. O. Branson et al.
DOI:
10.4236/apd.2017.63009 87 Advances in Parkinson’s Disease
1. Introduction
Parkinson’s disease (PD) is a progressive neurodegenerative disorder diagnosed
primarily by clinical presentation and neurological examination. The prevalence
of PD among the elderly population is approximately 1.6% [1]. The etiology and
prevalence of PD is probably in most cases multifactorial with genetic and envi-
ronmental risk factors. The most contributing factors of PD include age, sex,
geographic location and race [1]. There is still limited knowledge in how race af-
fects incidence of PD. African-Americans (AA) are diagnosed with PD at half
the rate of Caucasians after controlling for age, sex, location of care, healthcare
use, and reason for Medicaid eligibility [2].
The difference in incidence rate of PD in AA compared to whites has not been
explained so far by insurance, income, location of care, or healthcare utilization.
Further analyses have been recommended to find other potential causes, such as
patient, physician and system factors. There have also been several studies ana-
lyzing patient perception and knowledge of PD among racial and ethnic groups.
African-Americans were less likely to report PD related disability compared to
whites based on a small sample size of PD patients using the Unified Parkinson
Disease Rating Scale (UPDRS) [3]. Understanding PD based on racial and ethnic
groups may provide insight into recognizing disparities of diagnosis. Pan
et al
.
completed a mixed-methods cross-sectional study involving PD focus groups
and survey study distributed to senior centers in Philadelphia, Pennsylvania. The
study revealed a lack of understanding about PD symptoms, fear of the diagnosis
and concern of becoming a burden to family [4].
However, under-reporting of PD symptoms does not entirely explain dispari-
ties in PD treatment [5] [6] [7]. Another possible cause of delay in diagnosis may
include a lack of referral from primary care physicians. Studies have shown that
initial diagnosis of Parkinson’s disease is done generally by the primary care [8].
Analyzing the PD referrals of patients of African descent compared to Cauca-
sians in a Movement Disorders clinic at an urban academic center serving a large
number of AA may provide understanding for the delay in diagnosis.
Boston Medical Center is the largest safety net hospital in New England, as
59% of the population it serves is disadvantaged due to lack of access to care,
race, ethnicity and social factors. The proportions of Blacks or AA and Whites or
Caucasians in the population seen at the hospital were respectively 29.1% and
33.6% in 2011. The demographics of patients seen in the general neurology clinic
are similar to the overall population at Boston Medical Center (AA 30.57% and
Caucasians 38.06%) (Table 1). Therefore, the movement disorders clinic should
have a comparable proportion of AA with idiopathic PD compared with Cauca-
sians if incidence were the same in the two populations. Based on a study that
analyzed the prevalence and incidence of Parkinson’s disease per year in the
United States Medicare beneficiary database, we expect that the incidence of PD
in our African-American population would be about half of what it is in Cauca-
sians [1]. This study, which was the largest to date analyzing incidence and pre-
C. O. Branson et al.
DOI:
10.4236/apd.2017.63009 88 Advances in Parkinson’s Disease
Table 1. Outpatient Neurology Visits at Boston Medical Center 10/24/2015-10/24/2016.
RACE
N
Total %
Asian
324 7.95%
American Indian/Native American
91 0.69%
Black/African American
4034 30.57%
Declined/Not Available
3703 28.10%
Hispanic or Latino
4 0.03%
Native Hawaiian/Pacific Islander
15 0.11%
White
5022 38.06%
(blank)
1 0.007%
valence of PD by race, age, sex and county, reported that the prevalence ratio of
PD among African-Americans compared to Caucasians in the general Medicare
population is about 5%.
2. Methods
Data were abstracted from the movement disorders database from the Boston
University Neurology Department. The database includes patients seen in the
outpatient neurology clinic who have a known diagnosis of Parkinsonism. Data
recorded include demographics, race, ethnicity, date of onset of symptoms, date
of diagnosis and insurance. Racial demographics are divided into ethnicity in-
cluding African-Black, -North and American-Black. The diagnosis is confirmed
by a Movement Disorders specialist within the neurology clinic at Boston Medi-
cal Center. The ratio of cases in the database was compared to the Medicare
population-based study of Parkinson’s disease [1]. The Institutional Review
Board at Boston University reviewed and approved the protocol.
Data Analysis
The prevalence ratio of PD among AA compared to Caucasians in the general
population is about 9% based upon the Willis article. The expected case ratio in
our population was determined by multiplying the prevalence ratio of AA com-
pared to Caucasians at Boston Medical Center in 2016, by the PD prevalence ra-
tio of AA compared to Caucasians based on the Willis article. This expected rate
was compared to the actual case ratio of AA compared to Caucasians with PD in
our database.
3. Results
Of the 488 patients were in the movement disorders database, 327 patients were
diagnosed with idiopathic PD and 161 were diagnosed with other neurological
disorders. There were 45 patients of African descent (sub-Sahara, northern-
Africa and African-American) in the database. Of these 45 patients, 18 or 40%
were diagnosed with idiopathic PD. There were 393 Caucasian patients in the
C. O. Branson et al.
DOI:
10.4236/apd.2017.63009 89 Advances in Parkinson’s Disease
database. Of these, two hundred and eighty seven or 73% were diagnosed with
idiopathic PD (Table 2).
Calculation of the expected case ratio was based upon the Willis
et al
. study,
which demonstrated a prevalence ratio for PD of 0.58 [1]. The prevalence ratio
of PD multiplied by the prevalence ratio of PD at Boston Medical Center in
African-Americans (including Hispanic/Latino/Spanish) was 8532, and in White
(Not Hispanic/Latino/Spanish) 10,082. The expected race (case) ratio of AA at
Boston Medical Center is therefore 0.58 × (0.84) = 0.49 or 49%. The actual case
ratio of AA patients in the Boston Medical Center Movement Disorder database
was 11%, and among patients with a diagnosis of idiopathic PD it was even low-
er at 6%, despite the large population of AA in the general Neurologic clinic.
4. Strengths and Limitations
Although this study provided a larger proportion of Africans-Americans com-
pared with non-Hispanic Caucasians than other studies analyzing the prevalence
ratio of patients with Parkinson’s disease [1] [2], our sample size was small. In
addition, all of the demographics at Boston Medical Center were not analyzed.
The demographics were obtained for all of the patients within the database and
are summarized in Table 3; the sample size was too small for additional analysis
by other demographic characteristics. The strength of the study is that all of
Table 2. Racial demographics in the movement disorders database.
RACE
Without
iPD
With
iPD
Total
African-American*
African-Black (Sub-Sahara)
6 2 8
African-North (Sahara or Northern Regions: Algeria, Egypt,
Morocco, Tunisia, Etc.) 2 2 4
American-Black (African descent, originating in: Canada,
Caribbean, Brazil, US, etc.) 19 14 33
American Indian/Alaska Native
0 2 2
Asian-East (China, Japan, Korea, etc.)
4 8 12
Asian-West (Bangladesh, India, Iran, Iraq, Pakistan, etc.)
4 2 6
Caucasian
106 287 393
Mixed Race
1 0 1
Native Hawaiian or Other Pacific Islander
0 1 1
Not in EMR (Declined/Not Available)
0 1 1
Other—No category above reflects origin
4 0 4
Spanish (Cuban, Iberian Peninsula, Mexican, South or
Central American, or Other Spanish Origin)
15 8 23
*African-American, including African-Black (Sub-Sahara); North (Sahara or Northern regions: Algeria,
Egypt, Morocco, Tunicia, etc.); American-Black (African descent, originating in: Canada, Caribbean, Brazil,
US etc.).
C. O. Branson et al.
DOI:
10.4236/apd.2017.63009 90 Advances in Parkinson’s Disease
Table 3. Demographic characteristics of the movement disorders database.
Patient Demographics
Gender
Women
50.2% (245)
Men
49.7% (243)
Race
Caucasian
80.5% (393)
African American:
9.2% (45)
American-Black (African descent, originationg in: Canada, Carribean, Brazil, US, etc.)
6.8% (33)
African-Black (Sub-Sahara)
1.6% (8)
African-North (Sahara or Northern Regions: Algeria, Egypt, Morocco, Tunisia, etc.)
0.8% (4)
Spanish (Cuban, Iberian Peninsula, Mexican, South or Central American, or Other Spanish Origian)
4.7% (23)
Asian:
3.7% (18)
Asian-East (China, Japan, Korea, etc.)
2.5% (12)
Asian-West (Bangladesh, India, Iran, Iraq, Pakistan, etc.)
1.2% (6)
Other—No category above reflects origin
0.8% (4)
American Indian/Alaska Native
0.4% (2)
Mixed Race
0.2% (1)
Native Hawaiian or Other Pacific Islander
0.2% (1)
Not in EMR (Declined/Not Available)
0.2% (1)
Education
Bachelor's degree
25.8% (126)
Graduate or Professional degree
21.1% (103)
High School degree/GED
20.9% (102)
Not Documented
14.1% (69)
Some College, no degree
8.4% (41)
<High School
3.9% (19)
Some High School, bo degree
3.7% (18)
Associate degree
2.0% (10)
Occupation
Not in the Labor Force
69.1% (337)
Management, Professional, Related
12.3% (60)
Sales
5.9% (29)
Not Documented
4.5% (22)
Service
4.1% (20)
Construction, Extraction, Maintenance
2.3% (11)
Production, Transport, Material Moving
1.8% (9)
Insurance
Medicare or Medicaid
53.3 % (260)
Private
35.7% (174)
Not Documented
7.4% (36)
Free care
2.7% (13)
Self pay
1.0% (5)
C. O. Branson et al.
DOI:
10.4236/apd.2017.63009 91 Advances in Parkinson’s Disease
the patients were examined and diagnosed by movement disorders specialists.
5. Discussion
The dominant contributing factors in the prevalence of Parkinson’s disease (PD)
include age, sex, race and geographic location [1]. An article reviewed the litera-
ture regarding racial difference in the prevalence of Parkinson’s disease and how
it may change the overall outcome for patients [7]. Many of the studies found a
disproportionate number of AA with PD receiving less care, even when many of
them received care in tertiary teaching hospitals with higher than average num-
bers of neurologists and neurosurgeons who may specialize in advanced treat-
ment of PD, such as deep brain stimulation.
Boston Medical Center is also a tertiary hospital and provides care to a large
proportion of AA. Therefore, it is expected that the Movement Disorders group
at Boston Medical Center would also care for a large proportion of AA with PD,
even taking into account the smaller incidence and prevalence of PD in that
population. However, this is not the case based upon the analysis of our move-
ment disorders database. Many of the patients with idiopathic PD are Caucasian
and the observed ratio of AA with PD (6% vs 49% expected) is much lower than
expected. This may suggest referral bias among physicians at Boston Medical
Center, which may cause an under-diagnosis of PD among African-Americans.
A recent systematic review of the literature analyzing racial disparities in PD
analyzed the differences in PD diagnosis and treatment among AA compared to
non-Hispanic Caucasians [9]. These disparities may erroneously lower the pre-
valence of PD in the AA population [10]. A few studies also analyzed the percep-
tion and knowledge of PD among racial and ethnic groups to obtain a better
understanding of the disparities that were observed [4] [11]. There is however
no detailed study of the physicians’ perception of PD among diverse popula-
tions, so the biases that are affecting diagnosis are not well understood.
Our results further support Dahodwala
et al
.’s conclusion that racial differ-
ences in PD are not due to the clinical needs or appropriateness of care [2]. The
lower prevalence of PD at Boston Medical Center may suggest referral bias with
fewer African-Americans being referred by practitioners for evaluation and
possible diagnosis of Parkinson’s disease. This is important as there is a direct
link between greater survival among PD patients and receiving care from a neu-
rologist [8]. Therefore, it is essential to understand how PD patients are referred
to Movement Disorders clinics to improve overall access for all ethnic and racial
groups.
References
[1] Wright Willis, A., Evanoff, B.A., Lian, M., Criswell, S.R. and Racette, B.A. (2010)
Geographic and Ethnic Variation in Parkinson Disease: A Population-Based Study
of US Medicare Beneficiaries.
Neuroepidemiology,
34, 143-151.
https://doi.org/10.1159/000275491
[2] Dahodwala, N., Siderowf, A., Xie, M., Noll, E., Stern, M. and Mandell, D.S. (2009)
C. O. Branson et al.
DOI:
10.4236/apd.2017.63009 92 Advances in Parkinson’s Disease
Racial Differences in the Diagnosis of Parkinson’s Disease.
Movement Disorders
,
24, 1200-1205. https://doi.org/10.1002/mds.22557
[3] Dahodwala, N., Karlawish, J., Siderowf, A., Duda, J.E. and Mandell, D.S. (2011) De-
layed Parkinson’s Disease Diagnosis among African-Americans: The Role of Re-
porting of Disability.
Neuroepidemiology
, 36, 150-154.
https://doi.org/10.1159/000324935
[4] Pan, S., Stutzbach, J., Reichwein, S., Lee, B.K. and Dahodwala, N. (2014) Knowledge
and Attitudes about Parkinson’s Disease among a Diverse Group of Older Adults.
Journal of Cross
-
Cultural Gerontology
, 29, 339-352.
https://doi.org/10.1007/s10823-014-9233-x
[5] Chan, A.K., McGovern, R.A., Brown, L.T., Sheehy, J.P., Zacharia, B.E., Mikell, C.B.,
Bruce, S.S., Ford, B. and McKhann, G.M. (2014) Disparities in Access to Deep Brain
Stimulation Surgery for Parkinson Disease: Interaction between African-American
Race and Medicaid Use.
JAMA neurology
, 71, 291-299.
https://doi.org/10.1001/jamaneurol.2013.5798
[6] Dahodwala, N., Xie, M., Noll, E., Siderowf, A. and Mandell, D.S. (2009) Treatment
Disparities in Parkinson’s Disease.
Annals of Neurology
, 66, 142-145.
https://doi.org/10.1002/ana.21774
[7] Cheng, E.M., Siderowf, A.D., Swarztrauber, K., Lee, M., Vassar, S., Jacob, E., Eisa,
M.S. and Vickrey, B.G. (2008) Disparities of Care in Veterans with Parkinson’s
Disease.
Parkinsonism & Related Disorders
, 14, 8-14.
https://doi.org/10.1016/j.parkreldis.2007.05.001
[8] Willis, A.W., Schootman, M., Evanoff, B.A., Perlmutter, J.S. and Racette, B.A.
(2011) Neurologist Care in Parkinson Disease a Utilization, Outcomes, and Survival
Study.
Neurology
, 77, 851-857. https://doi.org/10.1212/WNL.0b013e31822c9123
[9] Branson, C.O., Ferree, A., Hohler, A.D. and Saint-Hilaire, M.H. (2016) Racial Dis-
parities in Parkinson Disease: A Systematic Review of the Literature.
Advances in
Parkinson
’
s Disease
, 5, 87. https://doi.org/10.4236/apd.2016.54011
[10] McInerney-Leo, A., Gwinn-Hardy, K. and Nussbaum, R.L. (2004) Prevalence of
Parkinson’s Disease in Populations of African Ancestry: A Review.
Journal of the
National Medical Association
,
96, 974-979.
[11] Dahodwala, N., Karlawish, J., Shea, J.A., Zubritsky, C., Stern, M. and Mandell, D.S.
(2012) Validation of an Instrument to Measure Older Adults’ Expectations Regard-
ing Movement (ERM).
PloS One
, 7, e43854.
https://doi.org/10.1371/journal.pone.0043854
Submit or recommend next manuscript to SCIRP and we will provide best
service for you:
Accepting pre-submission inquiries through Email, Facebook, LinkedIn, Twitter, etc.
A wide selection of journals (inclusive of 9 subjects, more than 200 journals)
Providing 24-hour high-quality service
User-friendly online submission system
Fair and swift peer-review system
Efficient typesetting and proofreading procedure
Display of the result of downloads and visits, as well as the number of cited articles
Maximum dissemination of your research work
Submit your manuscript at: http://papersubmission.scirp.org/
Or contact apd@scirp.org