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A Short Commentary on the Racial Disparities in Parkinson’s Disease

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Abstract

The etiology of Parkinson Disease (PD) remains elusive, but may include environmental and genetic factors leading to neuronal degeneration [1]. The difference in incidence of PD among different racial groups may provide additional insight into the etiology. In 2004, McInerney-Leo et al. reviewed twenty studies analyzing the prevalence and incidence of PD among Caucasians, African-Americans in the United States and African populations [2]. The differences in prevalence of Parkinson’s disease and Parkinsonism could not be demonstrated because of poor designs and numerous biases, such as referral bias and differences in access to healthcare. Therefore, they were unable to determine the effect of race in PD. Yet, studies continue to suggest that there is a significantly higher prevalence of PD among Caucasians compared to other racial groups [3]
Short Commentary OMICS International
Branson and Saint-Hilaire, J Neurol Disord 2017, 5:2
DOI: 10.4172/2329-6895.1000338
Volume 5 • Issue 2 • 1000338
J Neurol Disord, an open access journal
ISSN: 2329-6895
Journal of Neurological Disorders
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ISSN: 2329-6895
A Short Commentary on the Racial Disparities in Parkinsons Disease
Chantale Branson* and Marie-Helene Saint-Hilaire
Department of Neurology, Boston University School of Medicine, 72 E. Concord St, C3, Boston, MA, USA
Short Commentary
e etiology of Parkinson Disease (PD) remains elusive, but
may include environmental and genetic factors leading to neuronal
degeneration [1]. e dierence in incidence of PD among dierent
racial groups may provide additional insight into the etiology. In 2004,
McInerney-Leo et al. reviewed twenty studies analyzing the prevalence
and incidence of PD among Caucasians, African-Americans in the
United States and African populations [2]. e dierences in prevalence
of Parkinsons disease and Parkinsonism could not be demonstrated
because of poor designs and numerous biases, such as referral bias
and dierences in access to healthcare. erefore, they were unable
to determine the eect of race in PD. Yet, studies continue to suggest
that there is a signicantly higher prevalence of PD among Caucasians
compared to other racial groups [3]
We completed a literature review of studies that analyzed the
impact of racial disparities in diagnosis and treatment of PD [3]. A
search was performed in PubMed and Medline from 2004 to 2016, for
articles about racial disparities and Parkinsons disease. e time-frame
covered articles published aer the McInerney-Leo et al. review.
ere were twelve studies that analyzed prevalence, incidence
and perception of Parkinson’s disease among several races, but mostly
comparing African-Americans and Caucasians. Six of the twelve studies
included Hispanic or Latino, Asian, and Native American populations
[3]. Some studies also focused on disparities in treatment and patient
care [3].
All of the studies, whether using data from tertiary centers, databases
or death certicates, concluded that the prevalence and incidence of
PD was higher in Caucasians than in African-Americans. Studies using
information from databases, such as United States Medicare recipients,
Pennsylvania Medicaid claims or the Veterans Administration were able
to obtain accurate prevalence due to their large sample size, compared
with studies at tertiary movement disorders centers. For example,
Willis’ study of the US Medicare Database included 450,000 PD cases
per year [4]. ere was only one study that used death certicates to
understand the prevalence of PD, which highlighted socioeconomic
bias in reporting Parkinsons disease at death [5].
Several of the studies observed treatment disparities in PD
treatment among African-Americans compared to Caucasians [6-8].
e lack of treatment for PD can lead to increased morbidity, decreased
quality of life and cause more rapid progression to disability [8]. Aer
controlling for demographics, age, sex, geography and initial visit with
a neurologist, about only one third of African-Americans with PD
were started on any therapy, including physical therapy. While authors
were unable to determine the cause of the treatment disparities, the
ndings raised the possibility of problems with the quality of provider
communication [8]. African-Americans were also less likely to receive
Deep Brain Stimulation treatment for refractory PD despite being at a
tertiary center with a comprehensive neurology and neurosurgery team
[6]. ere were limitations with these studies as they were retrospective,
and based on Medicaid claims, ICD-9 charts and national database.
Dierences in PD prevalence can also be caused by patients’ own
perception of disease and expectation of aging, aecting decision to
*Corresponding author: Branson C, Department of Neurology, Boston University
School of Medicine, MA, USA, Tel: 6176387729; E-mail: cmurray@bu.edu
Received April 06, 2017; Accepted April 26, 2017; Published April 28, 2017
Citation: Branson C, Saint-Hilaire M (2017) A Short Commentary on the Racial
Disparities in Parkinson’s Disease. J Neurol Disord 5: 338. doi:10.4172/2329-
6895.1000338
Copyright: © 2017 Branson C, et al. This is an open-access article distributed
under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the
original author and source are credited.
seek care. ere was one mixed-methods study that analyzed the
knowledge and attitude about Parkinson’s disease among older adults
[9]. Barriers to PD care included level of knowledge, lack of trust in the
healthcare system, language problems and attitudes about PD, such as
underreporting [10].
Hospital and out-patient based studies are not ideal study designs
to provide eective analysis of PD incidence or prevalence given
confounders, such as socioeconomic status, cultural factors, and
selection of the population being referred to a specialized center [11].
Further studies are needed, and should include a long-term community
based prospective design. is type of design would improve the overall
biases found in retrospective studies, and better assess if there is delay in
diagnosis, or under-diagnosis of Parkinson’s disease. is type of study
has yet to be performed. So far we are still unable to determine a clear
cause for the observed racial dierences in diagnosis and treatment of
Parkinson’s disease.
e limitations of our review article included a lack of studies
analyzing incidence, which may provide a direct link between race and
risk of PD. ere were a few articles that discussed incidence within
their cross-sectional study design, but none of the studies included
a prospective cohort design [4,12]. e article did not fully address
demographic variables that may also indirectly link race to risk of PD,
such as rural areas compared to urban areas.
All the above studies revealed racial dierences in the diagnosis and
treatment of PD that were not explained by location of care, insurance,
income, healthcare utilization, clinical factors, age, sex, geography or
initial visit with a neurologist. Many of the studies concluded that the
dierences were explained by racial disparities, dened as partiality or
inequity. e types of disparities included patient’s knowledge, as well
as expectation of the disease process, diagnosis with underreporting
and treatment from physical therapy, PD medications and deep brain
stimulation. Additional studies evaluating genetic factors or biological
factors, such as a population-based study are needed to further
understand PD prevalence.
References
1. Pringsheim T, Jette N, Frolkis A, Steeves TDL (2014) The prevalence of
Parkinson’s disease: A systematic review and meta-analysis. Movement
Disorders 29: 1583-1590.
2. McInerney-Leo A, Gwinn-Hardy K, Nussbaum RL (2004) Prevalence of
Parkinson’s disease in populations of African ancestry: A review. J Natl Med
Assoc 96(7): 974-979.
3. Branson CO, Ferree A, Hohler AD, Saint-Hilaire MH (2016) Racial disparities
Citation: Branson C, Saint-Hilaire M (2017) A Short Commentary on the Racial Disparities in Parkinson’s Disease. J Neurol Disord 5: 338. doi:10.4172/2329-
6895.1000338
Page 2 of 2
Volume 5 • Issue 2 • 1000338
J Neurol Disord, an open access journal
ISSN: 2329-6895
in Parkinson’s disease: A Systematic Review of the Literature. Advances in
Parkinson’s Disease 5(4): 87-96.
4. Willis WA, Evanoff BA, Lian M, Criswall SR, Racette BA (2010) Geographic and
ethnic variation in Parkinson disease: A population-based study of US Meidcare
beneciaries. Neuroepidemiology. 34(3): 143-151.
5. Pressley JC, Tang MX, Marder K, Cote LJ, Mayeux R (2005) Disparities in
the recording of Parkinson’s disease on death certicates. Movement disorders
20(3): 315-321.
6. Chan AK, McGovern RA, Brown LT, Sheehy JP, Zacharia BE, et al. (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.
7. Cheng EM, Siderowf AD, Swarztrauber K, Lee M, Vassar S, et al. (2008)
Disparities of care in veterans with Parkinson’s disease. Parkinsonism &
Related Disorders 14: 8-14.
8. Dahodwala N, Xie M, Noll E, Siderowf A, Mandell DS (2009) Treatment
disparities in Parkinson’s disease. Annals of Neurology 66: 142-145.
9. Pan S, Stutzbach J, Reichwein S, Lee BK, Dahodwala N (2014) Knowledge
and attitudes about Parkinson’s disease among a diverse group of older adults.
Journal of Cross-cultural Gerontology. 29(3): 339-352.
10. Dahodwala N, Karlawish J, Siderowf A, Duda JE, Mandell DS (2011) Delayed
Parkinson’s disease diagnosis among African-Americans: The role of reporting
of disability. Neuroepidemiology 36(3): 150-154.
11. Hemming JP, Gruber-Badini AL, Anderson KE, Fishman PS, Reich SG, et
al. (2011) Racial and socioeconomic disparities in Parkinsonism. Archives of
neurology. 68(4): 498-503.
12. Dahodwala N, Siderowf A, Xie M, Noll E, Stern M, et al. (2009) Racial
differences in the diagnosis of Parkinson’s disease. Movement Disorders 24(8):
1200-1205.
Citation: Branson C, Saint-Hilaire M (2017) A Short Commentary on the Racial
Disparities in Parkinson’s Disease. J Neurol Disord 5: 338. doi:10.4172/2329-
6895.1000338
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