Adjust Text Size:change font sizechange font sizechange font sizechange font sizechange font sizechange font size

Access to the latest research — for scientists and people living with PD alike — in PDF's new scientific journal.

Browse Now

Parkinson's HelpLine


Learn More

Science News

Race and Income Level Tied to Differences in Parkinsonís Severity


In a new study of people with symptoms of Parkinson’s disease (PD), researchers found that African Americans and those with lower levels of income and education had more severe symptoms and higher levels of disability than did whites.  The report appears in the December 13, 2010 online edition of Archives of Neurology.

Earlier studies have shown that racial minorities and people of lower socioeconomic status tend to be at a more advanced stage of disease when they are diagnosed with conditions such as diabetes, heart disease or Alzheimer’s disease.  The authors of the new study set out to identify possible racial and socioeconomic disparities in people with parkinsonism. 

Led by Lisa M. Shulman, M.D., at the University of Maryland School Of Medicine, the study authors evaluated 1159 people who were seen in a subspecialty clinic with parkinsonism between 2003 and 2008.  About 80 percent of study participants had been diagnosed with PD.  The rest had parkinsonian symptoms such as stiffness, tremor and rigidity

On a questionnaire, participants provided information about their age, race, time since diagnosis, household income and education level.  The researchers used several standardized scales (such as the United Parkinson’s Disease Ranking Scale, UPDRS) to assess participants’ disease status, level of difficulty with activities of daily living, and disability.  Evaluation of the participants also included a medical history, noting which medications had been prescribed, and a neurologic examination. 



  • 1,024 of participants (93 percent ) were white and 66 (six percent) were African American.
  • African American and white participants were similar in age, cognitive function, percentage with PD, and years since diagnosis. 
  • Among all participants, 61 percent earned more than $50,000 per year and 63 percent had completed college.  
  • African Americans scored ten points higher on average than whites on the UPDRS, indicating a higher level of disability.
  • African Americans were prescribed fewer dopaminergic medications such as carbidopa/levodopa (Sinemet®), in particular newer drugs such as dopamine agonists.
  • Lower income was associated with more severe disease, those earning less than $30,000 were 15 points higher on the UPDRS than those earning more than $70,000.
  • Lower income participants were more often prescribed antidepressants, antipsychotics and antidementia agents.
  • College educated participants scored lower on the UPRDS by 10 points.


What Does it Mean?

This study underscores two important findings.  Both African Americans and people from low socioeconomic status are under-represented in a subspecialty movement disorders clinic when compared to their proportion of the population.  Furthermore, those of whom who are seen in the subspecialty clinics have a more severe clinical course of PD as seen in the higher UPDRS scores and the increased use of antipsychotic medications and medications for dementia.  The under-representation of these populations in the subspecialty clinics can be a result of biological causes, such as that PD is less common in African Americans (a notion that the authors of this report challenge), or from social and economical reasons.  Such explanations of the under-representation of African Americans and people from low socioeconomic status in a subspecialty clinic include delays in diagnosis, different patterns of referrals to specialists among physicians who treat various patient populations, access to care, economic reasons, or combinations of these factors.  In addition, it is possible that people experiencing parkinsonian symptoms may differ in their attitudes about when to seek medical help.  Some may simply believe that these symptoms are a normal part of aging.  If you or a loved-one are experiencing symptoms of Parkinson’s, PDF strongly urges you to consult your doctor.  

This study highlights the need for population based studies to assess the prevalence of PD and related disorders in disadvantaged population, such as the uninsured.  Researchers may have under-estimated the prevalence of the disease in these populations. 


Learn More

If you are interested in learning more about the signs of Parkinson's, visit PDF's symptoms page.

Learn about Symptoms


Reference: Hemming et al. Racial and Socioeconomic Disparities in Parkinsonism. Arch Neurol (2010) pp. archneurol.2010.326 EP -VL -IS -(


Source Date: Dec 21 2010