Table 1.
Research in African Americans with Parkinson’s disease
| Author, year | Population characteristics | Findings |
| Kessler II, 1972 [8] | Participants: Baltimore hospital discharges from 1965 to 1967 | Significantly lower numbers of African Americans with PD |
| Total subjects: 459 PD patients, | ||
| - 409 white, 50 African American | ||
| Age: <45 years | ||
| Pressley JC et al., 2005 [23] | Participants: National Health Interview Survey, 1986–1994 | PD less likely to be listed on death certificates of those with lower |
| Total subjects: 751 persons with PD, 283 with death certificates | socioeconomic status and less education | |
| - 37 African American, 676 white, 38 Hispanic/other | ||
| Age: <45 years | ||
| Schneider MG et al., 2009 [3] | All PD clinical trials published between 1985 and 2007 evaluated for minority enrollment | 17% of PD clinical trials reported minority enrollment 8% of participants in these studies were non-white |
| Cheng EM et al., 2008 [44] | Participants: VA patients in the LA area with ICD.9 diagnosis of PD verified by chart review with documented race/ethnicity | Disparities in treatment of depression in African Americans with PD in the VA system |
| Total subjects: 374 patients | ||
| - 309 White, 23 African Americans, 30 Hispanic, 11 Asian, 1 Native American | ||
| Age: <64 years | ||
| Dahodwala N et al., 2009 [15] | Participants: Pennsylvania State Medicaid Claims | Newly diagnosed African Americans |
| Total subjects: 307 incident cases | with PD are less likely to receive | |
| - 86% white, 14% African American | physical therapy or medications at | |
| Age: Mean age 55.1 | their first appointment | |
| Yacoubian TA et al., 2009 [16] | Participants: Subjects using PD medications REGARDS study | Lower PD medication use in African Americans as compared to whites |
| Total Subjects: 24,424 enrolled in REGARDS | in the REGARDS study | |
| - 41.7% African American, 54.1% White | ||
| Age: >45 | ||
| Gao X et al., 2009 [28] | Participants: Subjects enrolled in HPFS and NHS cohorts who had reported hair color, nested case-control with genotyping | Those with red hair and blonde hair had higher PD risk as compared to black hair |
| Total Subjects: 38,641 in HPFS, 93,661 in NHS | MC1 R Arg151Cys genotype | |
| - PD in 264 men, 275 in women | associated with PD | |
| - 272 cases genotyped | ||
| Age: mean age >43 years | ||
| Ross OA et al., 2010 [32] | Participants: DNA samples from 22 African American PD patients from Coriell Cell Repository collection | No frequent pathogenic mutations in African Americans with PD studied |
| Hemming JP et al., 2011 [42] | Participants: PD patients at a tertiary care center | African Americans with PD had |
| Total Subjects: 1090 patient with parkinsonism at a tertiary movement disorders center | higher Hoehn and Yahr stage at presentation as compared to whites with PD after controlling for education and income | |
| - 66 African American patients | ||
| - 1024 White patients | ||
| Age: | ||
| - mean age African American 67.1 | ||
| - mean age White 67 | ||
| Dahodwala N et al., 2011 [47] | Participants: Veterans with newly diagnosed PD at the Philadelphia Veterans Affairs Medical Center | African American men reported lower rates of disability even with similar exam findings to their white counterparts |
| Total Subjects: | ||
| - African Americans: 16 | ||
| - White: 58 | ||
| Age: mean age 70.1 years | ||
| Jain S et al., 2011 [29] | Participants: Adults in the Cardiovascular Health Study with PD | Lower urate levels associated with lower risk of PD, numbers of African Americans diagnosed with PD too low to have significant findings |
| Total Subjects: | ||
| - 5,749 total participants | ||
| - 154 with PD | ||
| - 84.2% white | ||
| Age: >65 years | ||
| McGuire V et al., 2011 [33] | Participants: consortium of five North American case-control studies with DNA samples | Taq1A DRD2 polymorphism was inversely associated with PD risk in African Americans studied |
| Total Subjects: | ||
| - 1325 newly diagnosed PD | ||
| - 1735 controls | ||
| - 2.2% PD were African American | ||
| Age: 37.2% <60 years, 62.8% >60 years | ||
| Wright Willis A et al., 2010 [14] | Participants: Retrospective cohort study of Medicare beneficiaries with incident PD from 2002–2008 | African Americans with PD had lowest rates of survival and highest rates of dementia diagnosis |
| Total Subjects: | ||
| - 138,728 with incident PD | ||
| - 6.1% African American | ||
| Age: >67 years old | ||
| Tilley BC et al., 2012 [51] | Participants: Movement disorders clinics already participating in National Institute of Neurologic Disorders and Stroke Exploratory Trials in Parkinson’s disease Long Term Study 1 | Interventions to increase minority enrollment in clinical trials through education of community providers were not effective |
| Chan AK et al., 2014 [43] | Participants: National Inpatient Sample Database | African Americans less likely to receive deep brain stimulation |
| Total Subjects: | ||
| - 18,312 PD DBS discharges from 2002 to 2009 | ||
| Age: Mean age for DBS 63.66 years | ||
| Pan S et al., 2014 [46] | Participants: Older adult members of 20 senior centers in Philadelphia | African Americans cited lack of insurance and poor trust in doctors as reasons why they would not seek treatment |
| Total Subjects: | ||
| - 75 adults in focus groups, 48% African Americans | ||
| - 154 completed questionnaires, 31% African American | ||
| Age: | ||
| - Focus group mean age 74.1 years (SD +/–8.0) | ||
| - Questionnaire mean age 76.1 years (SD +/–7.9) | ||
| Saadi A et al., 2017 [40] | Participants: Medical Expenditure Panel Survey participants from 2006–2013 | African Americans with neurological diagnosis less likely to see neurologists, more likely to have more hospital stays and more emergency room visits |
| Total Subjects: | ||
| - 16,936 self-reported neurologic conditions | ||
| - 3,102 African Americans | ||
| Age: <18 years to >65 years | ||
| Dahodwala N et al., 2017 [17] | Participants: Random sample of 5% of Medicare part A and B claims linked with Medicare Part D files from 2007–2010 including those with PD | African Americans and those of lower socioeconomic status are less likely to be prescribed PD medications |
| Total Subjects: | ||
| - 9482 to 9626 individuals with PD yearly | ||
| - 5.3% to 5.8% African Americans with PD yearly | ||
| Age: <65 years to >85 years | ||
| Fullard ME et al., 2017 [45] | Participants: Medicare beneficiaries with a diagnosis of PD in 2007 followed through 2009 | African Americans with PD are less likely to utilize physical or occupational therapy |
| Total Subjects: | ||
| - 174,643 PD patients | ||
| - 4.1% African American | ||
| Age: >65 years old, 90% over 70 years old | ||
| Chen H et al., 2017 [25] | Participants: Health, Aging and Body Composition study participants | Anosmia may not correlate with PD development in African Americans |
| Total Subjects: | ||
| - 1,510 white | ||
| - 952 African American | ||
| Age: | ||
| - Mean age white subjects 75.6 years | ||
| - Mean age African American 75.4 years | ||
| Mantri S et al., 2019 [24] | Participants: Medicare beneficiaries with PD diagnosis with 12 consecutive months of inpatient, outpatient, and prescription drug coverage from Jan 1, 2014 to Dec 31, 2014 | African Americans with PD more likely to be prescribed dementia treatment than any other ethnic group |
| Total Subjects: | ||
| - 268,407 with PD | ||
| - 5.5% African American | ||
| Age: | ||
| - Mean age 78.9 (SD +/–7.5) |