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Racial Disparities in Parkinson Disease: A Systematic Review of the Literature

January 2016
Advances in Parkinson's Disease 05(04):87-96

DOI:10.4236/apd.2016.54011

Authors:

Chantale Branson

Boston University

Anna DePold Hohler

Boston University

Marie saint-hilaire

Boston University

Racial differences in the prevalence of Parkinson’s disease (PD) have been reported for decades. Many of the earliest reports were flawed because they were based on crude datasets, such as hospital databases, death certificates, door-to-door surveys and records of Medicare beneficiaries. These studies provided conflicting results and were found to have numerous biases. Publications with improved study designs in recent years have yielded higher quality findings that are worth reviewing. We reviewed studies published between 2005 and 2014 that analyzed the racial differences in Parkinson’s disease diagnosis, treatment—including deep brain stimulation—and access to care. Literature searches were conducted in PubMed and EBSCO. These studies highlight advances in the field and explore differences in PD among ethnic and racial groups. Our literature review focused on prevalence, treatment and diagnosis discrepancies, and racial variations in the perceptions of aging. An appraisal of twelve reviewed studies determined a decrease in prevalence and incidence of PD in Americans of African descent compared to Caucasians. The studies also showed multiple health disparities, including lack of access to care, treatment, and inclusion in research. More studies are needed to address the causes and prevention of health disparities, as well as solutions, such as community outreach.

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Advances in Parkinson’s Disease, 2016, 5, 87-96

http://www.scirp.org/journal/apd

ISSN Online: 2169-9720

ISSN Print: 2169-9712

DOI: 10.4236/apd.2016.54011 November 25, 2016

Racial Disparities in Parkinson Disease: A

Systematic Review of the Literature

Chantale O. Branson, Andrew Ferree, Anna D. Hohler, Marie-Helene Saint-Hilaire

Department of Neurology, Boston University School of Medicine, Boston, MA, USA

Abstract

Racial differences in the prevalence of Parkinson’s disease (PD) have been reported

for decades.

Many of the earliest reports were flawed because they were based on

crude datasets, such as hospital databases, death certificates, door-to-

door surveys

and records of Medicare beneficiaries. These studies provided conflicting results and

were found to have numerous biases. Publications with improved study designs in

recent years have yielded higher quality findings that are worth reviewing. We r

viewed studies published between 2005 and 2014 that analyzed the racial differences

in Parkinson’s disease diagnosis, treatment—including deep brain stimulation—

and

access to care. Literature searches were conducted in PubMed and EBSCO. These

studies highlight advances in the field and explore differences in PD among ethnic

and racial groups. Our literature review focused on prevalence, treatment and dia

nosis discrepancies, and racial variations in the perceptions of aging. An appraisal of

twe

lve reviewed studies determined a decrease in prevalence and incidence of PD in

Americans of African descent compared to Caucasians. The studies also showed

multiple health disparities, including lack of access to care, treatment, and inclusion

in research

. More studies are needed to address the causes and prevention of health

disparities, as well as solutions, such as community outreach.

Keywords

Racial and Ethnic Disparities, Epidemiology, Parkinson’s Disease

1. Introduction

Parkinson’s disease (PD) is a neurodegenerative disorder that is diagnosed based on

clinical features, including bradykinesia, resting tremor, rigidity, and postural stability.

These clinical findings are essential for physicians to make an accurate diagnosis, which

subsequently will lead to improvement of clinical outcomes and quality of care. Studies

How to cite this paper:

Branson, C.O.

Ferree, A

., Hohler, A.D. and Saint-Hilaire,

.-H. (2016) Racial Disparities in Parkin-

son Disease: A Systematic Review of the Li

terature

Advances in Parkinson’s Dis

ease

, 87-96.

http://dx.doi.org/10.4236/apd.2016.54011

Received:

October 27, 2016

Accepted:

November 21, 2016

Published:

November 25, 2016

6 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.

have suggested there is a lower prevalence of PD among African-Americans. It is un-

clear if this is due to genetics, or inequalities among access to care, diagnosis, and

treatment.

In 2004, McInerney-Leo

et al

. analyzed prevalence and incidence of PD among Afri-

can-Americans compared to Caucasians [1]. There were six studies that analyzed the

prevalence and incidence of PD through hospital records, physician registration and

death certificates. The results were conflicting because of biased study designs, including

low power, healthcare access, physician bias and ascertainment bias. The article recom-

mended future studies conduct a long-term survey of the population to determine the

incidence and phenotype of PD among Caucasians compared to African-Americans.

Understanding the epidemiological characters of PD among minorities will help to

address the disparity in the care of this population. It will also ultimately provide a

deeper understanding of the biological, environmental, and genetic mechanisms of the

disease. Therefore, we undertook a literature review of racial disparities in PD focusing

on articles published since 2004.

2. Methods

We performed a database search of articles published after 2004 that studied racial dis-

parities in every facet of Parkinson’s disease among patients of African ancestry com-

pared to Caucasians. Topics included access to care, diagnosis, treatment, and inclusion

in research. A search in PubMed and Medline of literature with the following terms:

(racial disparities and Parkinson’s disease) and (racial disparities and veterans affairs)

resulted in ten studies; Two additional articles were obtained from references of the

studies elicited from PubMed and Medline. We reviewed twelve studies published be-

tween 2005 and 2014, which are found in Table 1. Many of the studies used the term

white for Caucasian and black for African-American. A summation of the studies in-

cluding the study design, study type, results, limitations and strengths are discussed

below.

3. Results

3.1. Studies at Tertiary Movement Disorders Centers

In 2011, Hemming

et al

. assessed the racial and socioeconomic disparities (annual in-

come and educational level) via cross-sectional analysis of patients seen at a tertiary

Movement Disorders center at the University of Maryland. The authors evaluated the

prevalence of PD among patients who self-identified as African-Americans compared

to whites (93.4% white and 6.1% African-American).

The study revealed that African-Americans, at the time of diagnosis, had greater

disability, disease severity, and were prescribed fewer anti-parkinson medications than

Caucasians. Most notably, African-Americans had a two-fold increase in years between

disease onset and diagnosis [2]. The limitations of this study included a small sample

size (66 African-Americans) and referral bias given a select population referred to a ter-

tiary center. Other confounding factors, such as socioeconomic status including income

C. O. Branson et al.

Table 1. Twelve studies analyzing the prevalence, incidence, management and treatment of PD among whites compared with non-whites.

Author & Journal

Studies

Study Sample

Comment

Pressley

et al

. 2005

Movement Disorders

Disparities in the Recording

of PD on Death Certificates

Black non-Hispanic

37/751 (4.9%)

White, non-Hispanic

676/751 (90.0%)

Hispanic/other

38/751 (5.1%)

By studying the prevalence of PD

based on death certificates the

findings showed socioeconomic

biases confounding the results.

Cheng

et al

. 2008

Parkinsonism and

Related Disorders

Disparities of care in

veterans with Parkinson’s

Non-Hispanic White

309/374 (82.62%)

African-American

N = 65/374 (9.35%)

Hispanic or Latino

N = 30/374 (8.02%)

Asian

N = 11/374 (2.94%)

Native American

N = 1/375 (0.27%)

6% racial/ethnic disparity of

adherence to PD quality

indicators among non-Hispanic

whites compared to non-whites

with PD.

Dahodwala

et al

. 2009

Annals of Neurology

Treatment disparities in

Parkinson's Disease

African-American

N = 43 (14%)

White

N = 264 (86%)

African-American patients did

not receive similar treatment for

PD compared to white patients.

Dahodwala

et al

. 2009

Movement Disorders

Racial Differences in the

Diagnosis of Parkinson’s

Disease

Non-Hispanic White

N = 123,489 (68%)

Black

N = 50,808 (28%)

Hispanic/Latino

N = 7,974 (4%)

PD diagnosis among African-

Americans was half the rate of

whites.

Willis

et al

. 2009

Neuroepidemiology

Geographic and Ethnic

Variation in Parkinson

Disease: A Population-Based

Study of US Medicare

Beneficiaries

White

N = 25,581,561 (86.6%)

Black

N = 2,356,271 (8.0%)

Hispanic

N = 593,234 (2.0%)

Asian

N = 470,024 (1.6%)

Native American

N = 96,262 (0.3%)

Unknown

N = 66,448 (0.2%)

Other

N = 367,034 (1.2%)

1. The mean prevalence of PD

per 100,000 is 1.6% of the elderly

population over 65 years of age.

2. Prevalence in Blacks and Asians

was 50% lower compared to Whites.

3. Blacks have a higher PD related

morbidity than whites.

Yacoubian

et al

. 2009

Neuroepidemiology

Racial Differences in Parkinson’s

Disease Medication Use in the

Reasons for Geographic and

Racial Differences in Stroke

Cohort: A Cross-Sectional Study

Black

N = 10,123 (41.7%)

White

N = 14,242 (58.3%)

1. Whites more frequently used PD

medications compared with blacks.

2. The group without health insurance

was less likely to take PD medications.

Dahodwala

et al

. 2011

Neuroepidemiology

Delayed Parkinson’s Disease

Diagnosis among African-Americans:

The role of reporting of disability

African-American

N = 16 (22%)

White

N = 58 (78%)

Newly diagnosed PD among African-

Americans were found to have a greater

motor impairment compared to whites.

Hemming

et al

. 2011

Archives Neurology

Racial and Socioeconomic

Disparities

in Parkinsonism

Total population

N = 1090

African-American

N = 66 (6.05%)

White

N = 1024 (93.94%)

African-Americans were found to

have a higher disability and disease

severity compared with whites at a

tertiary Movement Disorders Center.

Dahodwala

et al

2012 PLOS ONE

Validation of an Instrument to

Measure Older Adults’

Expectations Regarding

Movement (ERM)

Total population

N = 192

African-American

N = 60 (31%)

White

N = 119 (62%)

Latino

N = 3 (2%)

Understanding expectations about

movement among the elderly

through development of a scale.

Tilley

et al

. 2012

Clinical Trials

A randomized recruitment

intervention trial in Parkinson’s

disease to increase participant

diversity: early stopping for

lack of efficacy [15]

Caucasian

N = 1572 (90.2%)

African-American

N = 40 (2.3%)

Hispanic/Latino

N = 75 (4.3%)

Asian

N = 42 (2.4%)

Other

N = 13 (0.8%)

The Ancillary Trial lacked the overall

number of participants that were

needed for true analysis and was

stopped early.

C. O. Branson et al.

Continued

Pan

et al

. 2014

J Cross Cult

Gerontol

Knowledge and Attitudes About

Parkinson’s Disease Among a

Diverse Group of Older Adults

Focus group

75 total participants

African-American

48%

White

31%

Chinese-American

21%

Survey group

154 participants

African-American

31%

White

40%

Chinese-American

29%

Community members were found to

have a lower level of knowledge about

PD compared to PD support group

members.

Chan

et al

. 2014

JAMA Neurology

Disparities in Access to Deep

Brain Stimulation Surgery for

Parkinson Disease

White

82.50%

African American

6.54%

Hispanic

6.74%

Asian/Pacific Islander

2.16%

Native American

0.33%

Other

2.15%

4.7% of all PD discharges that

were African Americans, 0.1% were

DBS related discharges.

and level of education. The authors stated racial disparities are multi-faceted, and rec-

ommend additional studies that assess the attitudes of patients and physicians regard-

ing PD, PD referral and treatment.

3.2. Studies Using Databases

Willis

et al

. assessed racial differences in PD via a cross-sectional study, which also

identified potential environmental factors. In this study, PD cases were identified from

the United States Medicare benefit recipients with ICD-9 codes 332 or 332.0 in 1995,

and from 2000 to 2005. Benefits recipients with ICD-9 codes 332.1 (secondary Parkin-

sonism) or 333.0 (other degenerative disease of the basal ganglia) were excluded. The

sample size was 450,000 PD cases per year. Medicare denominator files included birth,

race, sex, residence, zip code, and mortality data for US Americans over the age of 65. It

did not include people who were eligible for Medicare, but were in a health mainten-

ance organization. The mean prevalence of PD was 1,588.43/100,000 among Medicare

beneficiaries over age 65. Of the Medicare recipients, the mean age-related prevalence

of PD was 1671.63/100,000 among Caucasian enrollees and 1,036.41/100,000 among

African-American enrollees. The mean annual incidence of PD for Medicare recipients

from 2002 to 2005 was 445.79/100,000 and this remained stable since 1995 [3].

This was a well-designed study, which was well powered due to the large sample size.

It also analyzed the prevalence and incidence of PD, which included demographic as

well as geographic factors. Willis

et al

. confirmed that the prevalence among African-

Americans were fifty percent lower than the prevalence among Caucasians. The inci-

dence ratio among African-Americans as compared to Caucasians were higher than the

prevalence ratio, suggesting African-Americans have a greater PD-related mortality

than Caucasians. The study also reduced referral and selection bias because the cases

were obtained from a database. Geographic and demographic variables were analyzed

as well, which revealed a higher prevalence of PD in the Midwest and Northeast areas.

The regions were termed the “Parkinson disease belt.” The limitations of this study in-

cluded data collection. Obtaining Medicare files excluded patients who were less than

C. O. Branson et al.

65 years of age. Although, the incidence of PD increases with age, the mean age of onset

is 61.6 years, so patients who are not yet on Medicare were excluded [4]. The use of

billing codes can result in false positives due to miscoding of other parkinsonian syn-

dromes as PD. The risk of false negatives may be higher among African-Americans if

there is a delay in diagnosing PD. Lack of access to care may exclude African-Americans

from obtaining Medicare.

In another study, Dahodwala

et al

. reviewed Pennsylvania Medicaid claims from

January 1, 1999 to December 31, 2003 to evaluate treatment disparities in PD [5]. Cases

that included a claim for secondary Parkinsonism, such as schizophrenia and bipolar

disorder were excluded. Three hundred seven new cases of PD were identified based on

the criteria of Medicaid enrollment, having one Medicaid reimbursement claim asso-

ciated with PD, and no previous claims associated with PD or Parkinsonism related

disorders.

Treatment for PD included medications, physical therapy and/or a return clinic visit

for PD within six months of the initial diagnosis. Of the new cases, 86% were Caucasian

and 14% were African-American. There were no statistical differences in age, sex, initial

diagnosis, or Medicaid eligibility between the two groups. Of the 307 cases, 104 were

prescribed medication or physical therapy while 124 received a second visit. One-third

of African-Americans received PD treatment compared to Caucasians (p = 0.002).

There were no differences in the number of return clinic visits. This study highlights

the racial disparities in treatment of PD. The authors hypothesized that lack of effective

communication from providers to African-American patients with PD may have con-

tributed to the gap in quality of care. It was also unclear, if the lower rate of treatment

among African-Americans were from the providers not prescribing, or the patients not

accepting treatment.

The study was limited by selection bias, as the patients with PD who applied for Me-

dicaid were typically low income and disabled. It also lacked documentation of the

clinical reasoning or decision making that may have contributed to African-Americans

not receiving treatments, such as comorbid conditions that make treatment difficult

[5]. The authors recommended interventions to address disparity, such as community,

patient and physician awareness, as well as developing interventions to reduce inequi-

ties in care. However, these were not discussed in detail.

Cheng

et al

. analyzed disparities of care among veterans with PD in a retrospective

study using ICD-9 code 332.0 from October 1, 2001 to September 30, 2002 followed by

further chart review of the same patients, from 1998 to 2004. Medical charts were re-

viewed by trained nurses blinded to the study hypothesis to confirm the diagnosis of

PD using ten indicator measures of PD care [6]. Out of five hundred seventy-seven

cases with ICD-9 code 332.0, four hundred one PD cases were confirmed. Of those cas-

es, twenty-seven were excluded due to lack of information about race or ethnicity. Re-

sults showed that physicians were more likely to confirm a diagnosis of PD among

Non-Hispanic Whites than non-Whites. Physicians assessed depression equally among

non-Hispanic whites and non-Whites, but the non-Hispanic whites were more likely to

C. O. Branson et al.

start treatment and receive follow-up. Patients who were offered treatment for depres-

sion and refused were included in the initial treatment group. Many providers did not

document if they offered treatment for depression among the untreated group.

3.3. Access and Treatment Disparities

Dahodwala

et al

., Cheng

et al

., and Chan

et al

. highlighted several ways race affects

access to healthcare and treatment. Each of the studies revealed that even after being

diagnosed with PD, African-American patients did not receive adequate first line me-

dications, physical therapy, treatment for depression, or referral for deep brain stimula-

tion (DBS) procedure [5] [6] [7].

African-Americans were found to have significantly fewer DBS procedures compared

to Whites (unadjusted odds ratio, 0.13; 95% confidence interval, 0.11 - 0.16; P < 0.001)

[7]. After adjusting for comorbidities that may contraindicate DBS, African-Americans

were eight times less likely to receive DBS treatment. Despite the fact that Afri-

can-Americans were more likely to receive care from urban hospitals with a higher

number of neurologists and neurosurgeons.

The disparities in care also included treatment for Parkinson’s disease depression

(PDD). Proper treatment of depression is associated with better quality of life. Cheng

. reported that physicians did not consistently document whether PD patients who

were depressed refused either medication or mental health referral. The rates of initial

treatment (92% vs. 80%, p = 0.04), and follow-up treatment (82% vs 64%, p = 0.05) of

depression among African-Americans were lower than non-Hispanic whites, despite

there being no difference between race and ethnicity in the assessment of depression

[6].

Dahodwala

et al

., reported that African-Americans were four times less likely than

whites to receive any PD treatment (odds ratio, 0.24; 95% confidence interval, 0.09 -

0.64), including physical therapy. This raises concern for communication breakdown

among the providers [5]. They also reported a difference in expectations between the

populations about normal aging.

3.4. Perceptions of Normal Aging

An interesting confounding variable regarding PD epidemiology in different popula-

tions is variation in perceptions of normal aging. Dahodwala and colleagues were the

first to examine this by comparing the stage of disease at which African-Americans and

white PD patients were first diagnosed [8]. By comparing records from the Philadelphia

Veterans Affairs Medical Center, they determined that African-American patients in-

itially presented at more advanced stages of disease compared to their white counter-

parts (Hoehn and Yahr stage, 2.5 vs 2.0). Surprisingly, despite greater motor impair-

ment, the degree of reported disability among African-Americans was half of what

whites reported (Unified Parkinson Disease Rating Scale-disability, 40% vs 81%). This

striking discovery regarding disease perception provides a plausible, yet likely partial,

explanation for the documented discrepancies in PD prevalence between African-

C. O. Branson et al.

Americans and Caucasians.

Discrepancies in perceptions of normal motor performance with aging was explored

directly again by Dahodwala and colleagues [9]. They generated a novel assessment tool

for testing participants’ views on Expectations Regarding Movement (ERM) with ques-

tions tailored for parkinsonian symptoms. The investigators used this questionnaire to

assess 210 senior center residents in Delaware County, Pennsylvania and demonstrated

African-Americans held significantly lower expectations for maintenance of mobility

compared to whites. However, there was no difference between the groups with respect

to expectations of aging in general. Other participant characteristics that significantly

improved ERM scores were higher education (more than high school) and better self-

reported health (very good or excellent).

Another study investigated the issue of perceptional variation in PD with a two-

pronged approach in senior communities in Philadelphia [10]. The study first held fo-

cus groups in senior centers to obtain a qualitative understanding of differences in

knowledge and perspectives on PD amongst whites, African-Americans and Chinese-

Americans. In the quantitative arm of the study, Pan and colleagues constructed a

questionnaire based on the findings from the 75 focus group participants. The ques-

tionnaire was administered to 154 individuals and revealed commonalities and differ-

ences between the three racial groups. Two common themes shared across groups were

an overall lack of knowledge regarding the disease, and concern over losing indepen-

dence as a consequence of developing PD. Distrust of the healthcare system and lan-

guage barriers were identified as unique obstacles to treatment perceived by African-

and Chinese-Americans. Echoing previous studies, African- and Chinese-Americans

were both more likely to view parkinsonian symptoms as part of normal aging com-

pared to whites.

These three illustrative studies revealed substantial differences in both expectations

for normal aging and perceived degree of disability from parkinsonian symptoms. The

work highlights a likely contributing factor in the variance in PD prevalence amongst

different racial and ethnic groups. These studies also point to the importance and need

for outreach and education regarding PD in the senior population.

4. Discussion

Many of the studies revealed the incidence and prevalence of PD are higher among-

Caucasians compared to African-Americans. Since the McInerny-Leo

et al

. literature

review many of the study designs have improved. Yet, there are still limitations making

it difficult to assess the overall prevalence of PD among African-Americans compared

to Caucasians. For example, Willis

et al

. provided the largest study to-date on PD inci-

dence and prevalence among African-American population compared to Caucasians by

using the Unites States health care database. There are several strengths within this

study, including the large sample size and serial cross-sectional study design. However,

there were a few limitations, including false positives, case clustering and under-diagnosis

due to lack of healthcare access, which may have skewed the overall prevalence of PD in

C. O. Branson et al.

the African-American population.

Studies analyzing access and treatment disparities revealed a delay in diagnosis and

treatment bias [8]. The studies were retrospective, which evaluated ICD-9 codes.

Therefore, they could not determine if the patient refused treatment or if the physician

did not offer standard treatment making it difficult to determine the cause of these dis-

parities. There were many hypotheses, which included underreporting of symptoms,

mistrust of the medical field and lack of effective communication between the patient

and physician [10]. African-Americans were also found to have greater disease severity

and disability compared to whites likely as a result of delay in diagnosis and treatment

[2]. The studies that revealed a treatment bias also did not address ways to prevent this

challenging issue.

There were two studies analyzing the misperceptions of motor performance with ag-

ing. Pan

et al

. analyzed expectations of normal aging via mixed-methods, which re-

vealed several barriers to attitudes and knowledge. Understanding these barriers would

improve delays in diagnosis and treatment. The study revealed African-Americans and

Chinese-Americans perceived parkinsonian symptoms as a part of normal aging.

Therefore, many of the symptoms that may seem vague to the patient become the phy-

sician’s responsibility to educate them and their care providers.

Are physicians asking the right questions to get an accurate history based on racial

and cultural differences? Additional training to the initial primary provider and out-

reach programs, such as increasing patient awareness are warranted.

McInerney-Leo

et al

., recommended future studies such as, a long-term survey of a

population with a similar proportion of Caucasians and African-Americans similar to

the door-to-door survey of Parkinson’s disease in Copiah County, Mississippi, and Ni-

geria [11]. Dahodwala

et al

., also analyzed racial differences in the diagnosis of Parkin-

son’s disease in a cohort study and they came to a similar conclusion. The racial differ-

ences in PD incidence were not elucidated by age, sex, income, insurance, geographic

variation or healthcare utilization. They concluded that the racial disparities were more

likely a result of discrimination or bias and a population-based approach will help de-

termine the root cause of these differences.

These studies support the need for a long population-based study to analyze the true

incidence of Parkinson’s disease and better understand how various biases can cause

under diagnosis and delay in treatment. It will also help with targeted interventions,

such as screening surveys, teaching measures to prevent under-reporting of symptoms

and under-diagnoses. Understanding the epidemiological constructs of race in PD will

allow us to have a better understanding of Parkinson’s disease and help us improve care

for an underserved population.

5. Conclusions

There were twelve studies analyzing the prevalence, incidence, management and treat-

ment of Parkinson’s disease among people of color compared with whites. The majority

of the studies used databases, such as the United States Medical benefit recipients, the

C. O. Branson et al.

Pennsylvania Medicaid claims, and death certificates and medical charts of veterans

with Parkinson’s disease [3] [5] [6] [12] [13]. Since the McInerney-Leo article, there has

been one cross-sectional study at a Movement Disorders center reviewing social and

socioeconomic disparities [2].

Studies analyzing access to care and management were retrospective chart reviews.

They found a disproportionate number of African-Americans receiving less care, in-

cluding medical treatment, physical therapy, depression management, and deep brain

stimulation. Although the studies did not analyze the causes of the disparities between

African Americans and whites, they highlighted a problem with communication and

under-reporting [5] [7] [8] [14].

Three studies analyzed the perception and knowledge of PD symptoms in different

populations [8] [9] [10]. These studies emphasized the differences between racial and

ethnic groups, but did not reveal the root of these perceptions.

The review articles revealed racial disparities in every facet of Parkinson’s disease,

from knowledge about the disease, to diagnosis, and finally treatment. Racial disparities

also existed within the Veterans’ Affairs health care system, which should provide an

equal standard of care to all veterans. Unfortunately, the studies do not address the

causes of these observations and further studies need to be conducted to determine ra-

cial. A community-based study has yet to be performed and may deepen our under-

standing of Parkinson’s disease.

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Preclinical Signs of Parkinson's Disease: a Possible Association of Parkinson's Disease with Skin and Hair Features

Article

Apr 2019
MED HYPOTHESES

Clinical and Epidemiological Aspects of Parkinson's Disease in the South of Western Siberia

Article

Full-text available

Nov 2020

Background: The article is devoted to one of the most common neurodegenerative diseases in the world-Parkinson's disease (PD), the prevalence of which in Russia reaches 140-150 people per 100,000 people. The clinical and anamnestic profile of a patient with PD is presented, the prevalence of motor and non-motor symptoms is reflected, and a comparative characteristic of the neurological deficit in the Siberian population of patients with other cohorts of patients with Parkinson's disease in different countries and ethnic groups is presented. Methods: We studied 140 patients with Parkinson's disease. A comprehensive assessment of neurological status was performed using the "Unified Parkinson's Disease Rating Scale (UPDRS)." In addition, we used the Beck Depression and MoCA scale test. Assessment of the presence and severity of olfactory dysfunction was performed using the Sniffin Stick odor identification test. The stage of PD was evaluated according to the classification of M. M. Hoehn and M. D. Yahr. Results: The cohort of the study was dominated by overweight patients with a higher level of education, with concomitant arterial hypertension, coronary heart disease, and dyslipidemia. The severity of motor and most non-motor symptoms directly correlates with the duration of PD and the stage of the disease. The predominant form of the disease was a mixed form, which was also noted in research cohorts in Canada and the UK. The Siberian cohort tends to be more prevalent in hyposmia, daytime sleepiness, orthostatic hypotension, and depressive and REM disorders. Conclusion: Our data show the importance of a comprehensive assessment of both motor and non-motor neurological deficits as well as the analysis of comorbid disorders and risk factors for the occurrence and progression of Parkinson's disease. They also show the prevalence of certain motor and non-motor symptoms in the Siberian cohort of patients with Parkinson's disease.

Hispanic Perspectives on Parkinson’s Disease Care and Research Participation

Article

Full-text available

Apr 2021
J ALZHEIMERS DIS

Background: Hispanics are under-represented in Parkinson's disease (PD) research despite the importance of diversity for results to apply to a wide range of patients. Objective: To investigate the perspective of Hispanic persons with Parkinson disease (PWP) regarding awareness, interest, and barriers to participation in research. Methods: We developed and administered a survey and qualitative interview in English and Spanish. For the survey, 62 Hispanic and 38 non-Hispanic PWP linked to a tertiary center were recruited in Arizona. For interviews, 20 Hispanic PWP, 20 caregivers, and six physicians providing service to Hispanic PWP in the community were recruited in California. Survey responses of Hispanic and non-Hispanic PWP were compared. Major survey themes were identified by applying grounded theory and open coding. Results: The survey found roughly half (Q1 54%, Q2 55%) of Hispanic PWP linked to a tertiary center knew about research; there was unawareness among community Hispanic PWP. Most preferred having physician recommendations for research participation and were willing to participate. Hispanics preferred teams who speak their native language and include family. Research engagement, PD knowledge, role of family, living with PD, PD care, pre-diagnosis/diagnosis emerged as themes from the interview. Conclusion: Barriers exist for participation of Hispanic PWP in research, primarily lack of awareness of PD research opportunities. Educating physicians of the need to encourage research participation of Hispanic PWP can address this. Physicians need to be aware of ongoing research and should not assume PWP disinterest. Including family members and providing research opportunities in their native language can increase research recruitment.

Innovative Recruitment Strategies to Increase Diversity of Participation in Parkinson’s Disease Research: The Fox Insight Cohort Experience

Article

Full-text available

Apr 2020

Background: Clinical research in Parkinson's disease (PD) faces practical and ethical challenges due to two interrelated problems: participant under-recruitment and lack of diversity. Fox Insight (FI) is a web-based longitudinal study collecting patient-reported outcomes and genetic data worldwide to inform therapeutic studies. FI's online platform provides an opportunity to evaluate online strategies for recruiting large, diverse research cohorts. Objective: This project aimed to determine 1) whether FI's digital marketing was associated with increased enrollment overall and from under-represented patient groups, compared to traditional recruitment methods; 2) the clinical and demographic characteristics of samples recruited online, and 3) the cost of this online recruitment. Method: FI recruitment during a 6-week baseline period without digital promotion was compared to recruitment during several periods of digital outreach. Separate online recruiting intervals included general online study promotion and unique Facebook and Google ad campaigns targeting under-represented subgroups: early PD, late/advanced PD, and residents of underrepresented/rural geographic areas. Results: Early PD, late PD, and geotargeting campaigns enrolled more individuals in their respective cohorts compared to baseline. All online campaigns also yielded greater total FI enrollment, attracting more participants who were non-White, Hispanic, older, female, and had lower educational attainment and income, and more medical comorbidities. Cost per new participant ranged from $21 (Facebook) to $108 (Google). Conclusion: Digital marketing may allow researchers to increase, accelerate, and diversify recruitment for PD clinical studies, by tailoring digital ads to target PD cohort characteristics.

Profile of social self-management practices in daily life with Parkinson’s disease is associated with symptom severity and health quality of life

Article

Apr 2020

Purpose: Social participation is a key determinant of healthy aging, yet little is known about how people with Parkinson’s disease manage social living. This study describes individual differences in social self-management practices and their association with symptom severity and health quality of life. Methods: People with Parkinson’s disease (N = 90) completed measures of healthy routines, activities and relationships, symptom severity, and health related quality of life. Cluster analysis identified profiles of social self-management practices. Analysis of variance tested differences between profiles in symptom severity and health quality of life. Results: Participants clustered into one of seven groups according to different combinations of three practices: health resources utilization, activities in home and community, and social support relationships. The healthiest cluster engaged equally in all three practices at above sample average degree of engagement. Four clusters that engaged at or above sample average in activities in home and community experienced less health problems than three clusters that engaged below average. Variation in aspects of social lifestyle unrelated to health appeared also to contribute to profile diversity. Conclusion: Findings provide insight into similarity and variation in how people with Parkinson’s disease engage with social self-management resources and point to person-centered interventions. • Implications for Rehabilitation • Social self-management is a biopsychosocial construct to identify and describe self-care practices that engage one’s social resources for managing healthful daily living. • People with Parkinson’s disease vary in their profiles of engaging in social self-management practices in daily living, and this variability relates to severity of symptoms and health quality of life. • Learning how to identify health-centered social self-management practices may help people with Parkinson’s disease to focus on the healthfulness of their own practices. • Learning how to strategically engage one’s social resources as part of self-care may help people with Parkinson’s disease to master managing their health and well-being in daily life.

A Pilot Study of Telehealth Mindfulness-Based Cognitive Therapy for Depression in Parkinson’s Disease

Article

May 2022

Introduction: Parkinson’s disease (PD) is characterized by high-rates of depression with limited evidence-based treatment options to improve mood. Objective: To expand therapeutic options, we evaluated the feasibility and effect of a telehealth mindfulness-based cognitive therapy intervention adapted for PD (MBCT-PD) in a sample of participants with DSM-5 depressive disorders. Methods: Fifteen participants with PD and clinically-significant depression completed 9 sessions of MBCT-PD. Depression, anxiety, and quality of life were evaluated at baseline, endpoint, and 1-month follow-up. Results: Telehealth MBCT-PD was feasible and beneficial. Completion rates exceeded 85% and treatment satisfaction rates were high. Notable improvements were observed for depression, anxiety, and quality of life over the course of the trial. Conclusion: Telehealth MBCT-PD shows promise and warrants further evaluation via randomized clinical trial with more diverse participants. Such research holds the potential to expand the range of therapeutic options for depression in PD, thereby setting the stage for personalized care.

How to Increase Diverse Representation in Parkinson's Disease Trials

Article

Dec 2021
Neurol Today

Stephanie Cajigal

Diet Quality and Nutrition Concerns of People with Parkinson’s Disease and Their Informal Caregivers: A Mixed Methods Study

Article

Jan 2022

Limited research exists regarding the diet quality and nutritional concerns of people with Parkinson's disease (PwPD) and their informal caregivers. The study's purpose was to assess diet quality via the Healthy Eating Index-2015 (HEI-2015) and self-reported nutrition concerns via semi-structured, dyadic interviews of 20 PwPD (69.7 ± 9.2 yrs) and their caregivers (66.7 ± 13.0 yrs). HEI-2015 scores were 58.3 ± 12.4 and 58.1 ± 10.6 for PwPD and caregivers, respectively. Reported dietary concerns related to PD included: change in appetite or amount eaten, gastrointestinal issues, food-medication management, chewing/swallowing issues, and change in taste/smell. The poor diet quality and nutrition concerns identified suggest nutrition professionals and caregivers are critical on the healthcare team to promote optimal health among PwPD. Future research should address overall and specific aspects of diet quality, and nutritional concerns identified by dyads in this study, such as gastrointestinal issues and food-medication management.

Preparedness for Serious Illnesses: Impact of Ethnicity, Mistrust, Perceived Discrimination, and Health Communication

Article

Sep 2021

Background Increasing severity of serious illness requires individuals to prepare and make decisions to mitigate adverse consequences of their illness. In a racial and ethnically diverse sample, the current study examined preparedness for serious illness among adults in California. Methods This cross-sectional study used data from the Survey of California Adults on Serious Illness and End-of-Life 2019. Participants included 542 non-Hispanic White (52%), non-Hispanic Black (28%), and Hispanic (20%) adults who reported at least one chronic medical condition that they perceived to be a serious illness. Race/ethnicity, socio-demographic factors, health status, discrimination, mistrust, and communication with provider were measured. To perform data analysis, we used logistic regression models. Results Our findings revealed that 19%, 24%, and 34% of non-Hispanic White, non-Hispanic Blacks, and Hispanic believed they were not prepared if their medical condition gets worse, respectively. Over 60% indicated that their healthcare providers never engaged them in discussions of their feelings of fear, stress, or sadness related to their illnesses. Results of bivariate analyses showed that race/ethnicity was associated with serious illness preparedness. However, multivariate analysis uncovered that serious illness preparedness was only lower in the presence of medical mistrust in healthcare providers, perceived discrimination, less communication with providers, and poorer quality of self-rated health. Conclusion This study draws attention to the need for healthcare systems and primary care providers to engage in effective discussions and education regarding serious illness preparedness with their patients, which can be beneficial for both individuals and family members and increase quality of care.

Discrimination and Medical Mistrust in a Racially and Ethnically Diverse Sample of California Adults

Article

Full-text available

Jan 2021

Purpose: Although we know that racial and ethnic minorities are more likely to have mistrust in the health care system, very limited knowledge exists on correlates of such medical mistrust among this population. In this study, we explored correlates of medical mistrust in a representative sample of adults. Methods: We analyzed cross-sectional study data from the Survey of California Adults on Serious Illness and End-of-Life 2019. We ascertained race/ethnicity, health status, perceived discrimination, demographics, socioeconomic factors, and medical mistrust. For data analysis, we used multinomial logistic regression models. Results: Analyses were based on 704 non-Hispanic Black adults, 711 Hispanic adults, and 913 non-Hispanic White adults. Racial/ethnic background was significantly associated with the level of medical mistrust. Adjusting for all covariates, odds of reporting medical mistrust were 73% higher (adjusted odds ratio [aOR] = 1.73; 95% CI, 1.15-2.61, P <.01) and 49% higher (aOR = 1.49; 95% CI, 1.02-2.17, P <.05) for non-Hispanic Black and Hispanic adults when compared with non-Hispanic White adults, respectively. Perceived discrimination was also associated with higher odds of medical mistrust. Indicating perceived discrimination due to income and insurance was associated with 98% higher odds of medical mistrust (aOR = 1.98; 95% CI, 1.71-2.29, P <.001). Similarly, the experience of discrimination due to racial/ethnic background and language was associated with a 25% increase in the odds of medical mistrust (aOR = 1.25; 95% CI, 1.10-1.43; P <.001). Conclusions: Perceived discrimination is correlated with medical mistrust. If this association is causal, that is, if perceived discrimination causes medical mistrust, then decreasing such discrimination may improve trust in medical clinicians and reduce disparities in health outcomes. Addressing discrimination in health care settings is appropriate for many reasons related to social justice. More longitudinal research is needed to understand how complex societal, economic, psychological, and historical factors contribute to medical mistrust. This type of research may in turn inform the design of multilevel community- and theory-based training models to increase the structural competency of health care clinicians so as to reduce medical mistrust.

Validation of an Instrument to Measure Older Adults' Expectations Regarding Movement (ERM)

Article

Full-text available

Aug 2012
PLOS ONE

Many individuals with Parkinson's disease are not diagnosed and treated. Attitudes about aging and related help-seeking may affect the timely diagnosis of Parkinson's disease. Our objectives were to develop measures of older adults' expectations regarding movement with aging, specifically related to parkinsonism, and their beliefs about seeking healthcare for the diagnosis and treatment of parkinsonism. We established content and face validity from interviews with experts, review of the literature, and pre-testing with key informants. Two 9-item instruments resulted: Expectations Regarding Movement (ERM) and Healthcare Seeking Beliefs for parkinsonism (HSB). These instruments were administered to 210 older adults at senior centers to investigate internal consistency and construct validity. 192 (91%) of the older adults completed more than 90% of the survey. The mean age was 76; 17 (9%) reported parkinsonism. Both scales demonstrated good internal consistency (α = 0.90). Factor analysis supported construct validity of the ERM and HSB scores. Older age, lower education, worse self-reported health and African American race each were associated with lower ERM scores, but not HSB scores. The ERM, a brief measure of expectations regarding movement with aging, shows reliability and validity. This scale may be useful in identifying older adults at increased risk for under-identification of Parkinson's disease. Further work is needed to measure healthcare seeking for parkinsonism.

Delayed Parkinson’s Disease Diagnosis among African-Americans: The Role of Reporting of Disability

Article

Full-text available

Apr 2011
NEUROEPIDEMIOLOGY

Racial differences in the observed prevalence of Parkinson's disease (PD) may be due to delayed diagnosis among African-Americans. We sought to compare the stage at which African-American and white PD patients present for healthcare, and determine whether perception of disability accounts for racial differences. Using records of veterans with newly diagnosed PD at the Philadelphia Veterans Affairs Medical Center, we calculated differences in reporting of symptoms as the difference in z-scores on the Unified Parkinson Disease Rating Scale part 2 (disability) and part 3 (motor impairment). Ordinal logistic regression was used to determine predictors of stage at diagnosis. African-American (n = 16) and white (n = 58) veterans with a mean age of 70.1 years were identified. African-Americans presented at a later PD stage than whites (median Hoehn + Yahr stage 2.5 vs. 2.0, p = 0.02) and were more likely to under-report disability relative to motor impairment (81 vs. 40%, p < 0.01). Multivariate analysis showed that under-reporting of disability accounted for much of the effect of race on stage of diagnosis. Under-reporting of disability among African-Americans may account for later stages of PD diagnosis than whites. This study begins to explain the mechanisms underlying observed racial disparities in PD.

Geographic and Ethnic Variation in Parkinson Disease: A Population-Based Study of US Medicare Beneficiaries

Article

Full-text available

Apr 2010
NEUROEPIDEMIOLOGY

Parkinson disease is a common neurodegenerative disease. The racial, sex, age, and geographic distributions of Parkinson disease in the US are unknown. We performed a serial cross-sectional study of US Medicare beneficiaries aged 65 and older from the years 1995, and 2000-2005. Using over 450,000 Parkinson disease cases per year, we calculated Parkinson disease prevalence and annual incidence by race, age, sex, and county. Spatial analysis investigated the geographic distribution of Parkinson disease. Age-standardized Parkinson disease prevalence (per 100,000) was 2,168.18 (+/-95.64) in White men, but 1,036.41 (+/-86.01) in Blacks, and 1,138.56 (+/-46.47) in Asians. The incidence ratio in Blacks as compared to Whites (0.74; 95% CI = 0.732-0.748) was higher than the prevalence ratio (0.58; 95% CI = 0.575-0.581), whereas the incidence ratio for Asians (0.69; 95% CI = 0.657-0.723) was similar to the prevalence ratio (0.62; 95% CI = 0.617-0.631). Bayesian mapping of Parkinson disease revealed a concentration in the Midwest and Northeast regions. Mean county incidence by quartile ranged from 279 to 3,111, and prevalence from 1,175 to 13,800 (per 100,000). Prevalence and incidence in urban counties were greater than in rural ones (p < 0.01). Cluster analysis supported a nonrandom distribution of both incident and prevalent Parkinson disease cases (p < 0.001). Parkinson disease is substantially more common in Whites, and is nonrandomly distributed in the Midwest and Northeastern US.

Racial Differences in Parkinson’s Disease Medication Use in the Reasons for Geographic and Racial Differences in Stroke Cohort: A Cross-Sectional Study

Article

Full-text available

Nov 2009
NEUROEPIDEMIOLOGY

Previous studies have suggested that African-American populations have a lower prevalence of Parkinson's disease (PD); however, because African-Americans are underrepresented in many cohorts, this relationship is poorly understood. We evaluated data from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study to describe potential racial differences in PD prevalence. We identified subjects using PD medications from the REGARDS study, a national longitudinal cohort study of 30,000 persons over age 45 with approximately equal representation of African-Americans and Whites. The prevalence of PD medication use across the cohort was 0.78% and was less among African-Americans (0.51%) than among Whites (0.97%; OR 1.90; 95% CI 1.31-2.74). There was an association of gender and PD medication use, with a prevalence of 0.61% in females and 0.97% in males (OR 1.57; 95% CI 1.13-2.18). There was no association with income, education level or geographic region of residence. The lower rate of PD medication use among African-Americans supports the suspected lower prevalence of PD among African-Americans suggested by other studies. While racial differences in PD diagnosis and treatment may contribute to the differences we observed, comparable disparities have not been observed in the REGARDS cohort for other diagnoses. Further studies of the REGARDS cohort may lead to important insights into potential biological differences in PD among African-Americans and Whites.

Age at onset and Parkinson disease phenotype

Article

Feb 2016

Objective: To explore clinical phenotype and characteristics of Parkinson disease (PD) at different ages at onset in recently diagnosed patients with untreated PD. Methods: We have analyzed baseline data from the Parkinson's Progression Markers Initiative database. Four hundred twenty-two patients with a diagnosis of PD confirmed by DaTSCAN imaging were divided into 4 groups according to age at onset (onset younger than 50 years, 50-59 years, 60-69 years, and 70 years or older) and investigated for differences in side, type and localization of symptoms, occurrence/severity of motor and nonmotor features, nigrostriatal function, and CSF biomarkers. Results: Older age at onset was associated with a more severe motor and nonmotor phenotype, a greater dopaminergic dysfunction on DaTSCAN, and reduction of CSF α-synuclein and total tau. The most common presentation was the combination of 2 or 3 motor symptoms (bradykinesia, resting tremor, and rigidity) with rigidity being more common in the young-onset group. In about 80% of the patients with localized onset, the arm was the most affected part of the body, with no difference across subgroups. Conclusions: Although the presentation of PD symptoms is similar across age subgroups, the severity of motor and nonmotor features, the impairment of striatal binding, and the levels of CSF biomarkers increase with age at onset. The variability of imaging and nonimaging biomarkers in patients with PD at different ages could hamper the results of future clinical trials.

Knowledge and Attitudes About Parkinson’s Disease Among a Diverse Group of Older Adults

Article

Apr 2014
J Cross Cult Gerontol

Underserved minorities are vulnerable to diagnostic delays and under-treatment of Parkinson's disease (PD). The purpose of this mixed-methods study was to understand knowledge and attitudes about PD among a racially/ethnically diverse group of community members. In the qualitative arm, ten homogeneous focus groups of 6 to 8 White, African-American and Chinese American older adults at senior centers in Philadelphia were conducted. Next, for the quantitative arm, a questionnaire of knowledge and attitudes about PD was administered among a larger group of senior center members. Themes were identified from the focus group discussions. ANOVA and chi-square tests were used to assess differences in PD knowledge and attitudes among the different racial/ethnic groups. Logistic regression analyzed for independent factors associated with barriers to treatment. Seventy-five adults participated in the focus groups (23 Whites, 36 African-Americans and 16 Chinese-Americans) and 154 completed the questionnaire (62 Whites, 47 African-Americans and 45 Chinese-Americans). One common theme about developing PD was fear of losing independence. Racial/ethnic groups identified unique barriers to care: mistrust in the healthcare system by African-Americans and language difficulties by Chinese-Americans. Eighty percent of all participants had no to some knowledge of PD. African-Americans and Chinese-Americans were more likely to perceive PD as a part of normal aging than whites. Chinese-Americans were more likely to perceive barriers to treatment than whites. A diverse sample of older adults demonstrated low levels of PD knowledge through both qualitative and quantitative methods. Many barriers to PD care were identified. Targeted community outreach and education efforts should incorporate information about PD and how to receive care.

Disparities in Access to Deep Brain Stimulation Surgery for Parkinson Disease Interaction Between African American Race and Medicaid Use

Article

Jan 2014

Importance: African American individuals experience barriers to accessing many types of health care in the United States, resulting in substantial health care disparities. To improve health care in this patient population, it is important to recognize and study the potential factors limiting access to care. Objective: To examine deep brain stimulation (DBS) use in Parkinson disease (PD) to determine which factors, among a variety of demographic, clinical, and socioeconomic variables, drive DBS use in the United States. Design, setting, and participants: We queried the Nationwide Inpatient Sample in combination with neurologist and neurological surgeon countywide density data from the Area Resource File. We used International Classification of Diseases, Ninth Revision codes to identify discharges of patients at multicenter, all-payer, nonfederal hospitals in the United States diagnosed with PD (code 332.0) who were admitted for implantation of intracranial neurostimulator lead(s) (code 02.39), DBS. Main outcomes and measures: We analyzed factors predicting DBS use in PD using a hierarchical logistic regression analysis including patient and hospital characteristics. Patient characteristics included age, sex, comorbidity score, race, income quartile of zip code, and insurance type. Hospital characteristics included teaching status, size, regional location, urban vs rural setting, experience with DBS discharges, year, and countywide density of neurologists and neurological surgeons. Results: Query of the Nationwide Inpatient Sample yielded 2,408,302 PD discharges from 2002 to 2009; 18,312 of these discharges were for DBS. Notably, 4.7% of all PD discharges were African American, while only 0.1% of DBS for PD discharges were African American. A number of factors in the hierarchical multivariate analysis predicted DBS use including younger age, male sex, increasing income quartile of patient zip code, large hospitals, teaching hospitals, urban setting, hospitals with higher number of annual discharges for PD, and increased countywide density of neurologists (P < .05). Predictors of nonuse included African American race (P < .001), Medicaid use (P < .001), and increasing comorbidity score (P < .001). Countywide density of neurological surgeons and Hispanic ethnicity were not significant predictors. Conclusions: AND RELEVANCE: Despite the fact that African American patients are more often discharged from hospitals with characteristics predicting DBS use (ie, urban teaching hospitals in areas with a higher than average density of neurologists), these patients received disproportionately fewer DBS procedures compared with their non-African American counterparts. Increased reliance on Medicaid in the African American population may predispose to the DBS use disparity. Various other factors may be responsible, including disparities in access to care, cultural biases or beliefs, and/or socioeconomic status.

A randomized recruitment intervention trial in Parkinson's disease to increase participant diversity: Early stopping for lack of efficacy

Article

Apr 2012
CLIN TRIALS

Failure to include participants of diverse race and ethnicity (i.e. those other than European Caucasian, non-Hispanic) in clinical trials impedes the safe development of new therapies given the potential for racial/ethnicity-related variations in treatment response. Increasing diversity is problematic for low prevalence diseases, where most community-based approaches do not reach those with the disease. Increase racial/ethnic diversity of participants in a Parkinson's disease therapeutic trial. We incorporated a randomized Ancillary Trial into the multisite National Institute of Neurologic Disorders and Stroke Exploratory Trials in Parkinson's Disease Long-Term Study 1. Movement disorders clinics already participating in long-term trial 1 were eligible and were the unit of randomization and analysis. At least 14% of adult residents over age 55 and living within 30 miles of the eligible site were from a diverse population, or there was a near-by zip code with a highly diverse population. Eligible sites also agreed to be randomized. The intervention was designed to increase community physicians' trust in long-term trial 1 investigators and address recruitment barriers in diverse populations. Primary outcomes included percentage of participants from diverse racial/ethnic groups enrolled in long-term trial 1, and qualitative findings from key informant interviews of the Ancillary Trial investigators and coordinators at the end of the trial. The Ancillary Trial stopped early for lack of efficacy, conditional power less than 1%. The 17 intervention sites had 12.6% diverse participants compared to 15.6% in 15 control clinics; odds ratio 0.82 (95% confidence interval = 0.32-2.16). In key informant interviews, high enrollers of diverse participants reported more use of existing physician relationships, untargeted community outreach, and extensive efforts to overcome participants' barriers. Low enrollers reported more use of patients in their practices and placed more responsibility for low enrollment on prospective participants. The Ancillary Trial included only those with Parkinson's disease. Whether our findings generalize to trials in other low prevalence diseases is unknown. Increasing diversity in Parkinson's disease clinical trials requires new paradigms for trial investigator and coordinator interactions with community physicians and prospective trial participants.

Racial and Socioeconomic Disparities in Parkinsonism

Article

Dec 2010

To assess potential racial and socioeconomic disparities in patients with parkinsonism treated at a tertiary Movement Disorders Center. Patients with parkinsonism were evaluated for demographics (age, race, annual income, and educational level), medical comorbidities, medication regimen, disability (Older Americans Resources and Services subscale), presence of Parkinson disease, and disease severity (Unified Parkinson Disease Rating Scale). Disability and disease severity measures were compared by race, income, and educational level using analysis of variance for continuous variables and χ(2) tests for dichotomous variables. The sample included 1159 patients with parkinsonism (93.4% white, 6.1% African American, 61.2% who earned more than $50,000 annually, 62.7% who completed college, and 79.2% with a diagnosis of Parkinson disease). Cross-sectional analyses by race, income, and educational level showed greater disability and disease severity in African American compared with white patients (African American vs white Older Americans Resources and Services subscale total score, 29.8 vs 25.3, P = .005; Unified Parkinson's Disease Rating Scale total score, 53.0 vs 42.8; P < .001). African Americans were less likely to be prescribed dopaminergic medications, particularly newer agents (African Americans 20.6% vs whites: 41.1%; P = .01). Lower income and lower educational level were independently associated with greater disease severity and disability (P < .003). Racial and socioeconomic disparities exist among patients with parkinsonism being treated at a tertiary Movement Disorders Center. African Americans and those with lower socioeconomic status have greater disease severity and disability than whites. These disparities may be because of problems in diagnosis, access to care, physician referrals, and patient attitudes regarding the appropriate threshold for seeking treatment at a specialized center. Understanding and correction of these disparities may improve outcomes.

Treatment Disparities in Parkinson's Disease

Article

Aug 2009
ANN NEUROL

We sought to identify racial disparities in the treatment of Parkinson's disease (PD). We identified 307 incident PD cases using Pennsylvania State Medicaid claims, and extracted claims for medications, physical therapy, and healthcare visits for the 6 months after diagnosis. After controlling for age, sex, and geography, African-Americans were four times less likely than whites to receive any PD treatment (odds ratio, 0.24; 95% confidence interval, 0.09-0.64), especially indicated medications. In a group with the same healthcare insurance, disparities in PD treatment exist. Physician and community awareness of these racial differences in PD treatment is the first step in addressing healthcare disparities.