Author(s): Dr. Raima Amin

Date Authored: December 30, 2019

Parkinson’s disease (PD) is the second most common age-related neurodegenerative disorder after Alzheimer’s disease, affecting 7-10 million people worldwide, and increasing with age. In the United States, it is estimated to affect around 1 million people. Among people over the age of 65, about 1% have Parkinson’s disease. Every year, about 60,000 Americans are newly diagnosed with the disease, though likely many more go undiagnosed (1). Based on estimates from a 2018 study by the Parkinson’s Foundation, there are a minimum of 17,000 people living with Parkinson’s disease in Washington state (2).  

Illustration of neurons
Illustration of neurons. Photo by Penn State (cc license).

The average age of diagnosis is 58. Female life expectancy is 84, and male life expectancy is 80. When well-cared for, people can live with Parkinson’s disease for 15-30 years from the time of diagnosis. Movement disorder neurologists are the experts in diagnosing and treating Parkinson’s disease, and they often work with a group of other professionals with expertise in Parkinson’s disease, such as physical, occupational and speech therapists, and social workers. Working with a team allows them to provide the most holistic care for the diverse needs of Parkinson’s disease patients. 

Studies analyzing ethnic and racial disparities in the incidence and care of Parkinson’s disease are limited, but suggest notable differences in the rates of diagnosis and type of care received. It is unclear whether the incidence and prevalence of Parkinson’s disease is the same between white and African American populations, but evidence suggests that Parkinson’s disease may be underdiagnosed in African Americans (3). Several studies show that African-Americans, at the time of diagnosis, often have greater disability and disease severity and are less likely to receive treatment for their disease compared to Caucasians (4-7). One study found that African-Americans were eight times less likely to receive deep brain stimulation for the treatment of Parkinson’s disease compared to whites (8). 

Healthcare access, patient/physician preferences, cultural perceptions of aging, and bias are some of the factors that may impact differences in diagnosis and treatment. One study found that African-Americans and Chinese-Americans are more likely to perceive parkinsonian symptoms as a part of normal aging, which may contribute to their relative delay in diagnosis and treatment compared to their White counterparts (9). Race, education level, and socioeconomic status of the patient may also influence a physician’s diagnosis or decision to refer to a specialist. Access to specialty care can vary across different communities, and for some, limited access to services can lead to delayed diagnosis and treatment. 

Local Resources 

The UW was recently awarded a grant through Washington State Representative Eric Pettigrew to study ethnic disparities in Parkinson’s disease diagnosis and treatment in Washington State. This grant will also support the development of a pilot program to target underserved communities, helping them gain access to specialist care and community services for Parkinson’s disease. The project is a collaboration between UW and Northwest Parkinson’s Foundation (NWPF), a local resource based in the Seattle area and serving the Northwest region of the United States that provides information about the disease and access to special programs for Parkinson’s disease patients and their loved ones (  


1. “Statistics.” Parkinson’s Foundation,

2. C Marras, JC Beck, JH Bower, E Roberts, B Ritz, GW Ross, RD Abbott, R Savica, SK Van Den Eeden, AW Willis, CM Tanner. “Prevalence of Parkinson’s disease across North America.” Nature Partner Journals. 2018. 

3. Pressley JCTang M-XMarder KCote LJMayeux R Disparities in the recording of Parkinson’s disease on death certificates. Mov Disord 2005;20 (3) 315- 321N Dahodwala, MD, M Xie, E Noll, A Siderowf, DS Mandell. “Treatment Disparities in Parkinson’s Disease.” Ann Neurology. 2009. 

4. Hemming, J.P., Gruber-Baldini, A.L., Anderson, K.E., Fishman, P.S., Reich, S.G., Weiner, W.J. and Shulman, L.M. (2011) Racial and Socioeconomic Disparities in Parkinsonism. Archives of Neurology, 68, 498-503. 

5. 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. 

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. 

7. 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. 

8. 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.