Major Finding: African Americans scored an average of 10 points higher on the Unified Parkinson's Disease Rating Scale than did whites.
Data Source: Single-center, observational cohort study of 1,024 white and 66 black patients with parkinsonism.
Disclosures: Dr. Hemming's associates reported ties to numerous manufacturers of drugs for Parkinson's disease.
African Americans with parkinsonism have more severe symptoms, more disability, and poorer symptom management than whites, according to a report published online Dec. 13.
These disparities cannot be attributed to differences between the races in age, cognitive function, or disease duration because these factors were comparable between blacks and whites in this single-center study. It appears that the racial disparities “may be explained by delayed diagnosis, referral patterns, access to care, economic factors, or a combination of all of these,” wrote Dr. J. Patrick Hemming and his associates at the University of Maryland, Baltimore (Arch. Neurol. 2010 Dec. 13 [doi: 10.1001/archneurol.2010.326]).
Independently of race, both lower socioeconomic status and lower education level also were associated with more severe signs and symptoms, greater disability, and poorer management of parkinsonism in this study.
“Studies in different patient populations and geographic locations are necessary to confirm these findings,” they noted.
Dr. Hemming and his colleagues evaluated 1,090 patients with parkinsonism who were participating in a quality of life assessment at the university's movement disorders center between 2003 and 2008. A total of 66 patients were African American and the rest were white; the researchers were unable to assess patients of other racial or ethnic backgrounds.
African Americans scored an average of 10 points higher on the Unified Parkinson's Disease Rating Scale than did whites (53 vs. 42.8).
The investigators called this finding a “striking difference that may influence mortality” because a previous study found that a one-point increase on the UPDRS was associated with a relative risk ratio of 1.1 for death within 7 years.
African Americans also had worse scores than did whites on a modified version of the Older Americans Resource and Services (OARS) disability subscale, which measures the level of difficulty in performing 14 daily activities.
Significantly fewer African Americans were prescribed antiparkinson medications than were whites (62% vs. 78%), and fewer African Americans also were receiving new dopaminergic agents (21% vs. 41%). In contrast, significantly more black patients used antipsychotic medications than did whites (13% vs. 6%).
When the data were analyzed by income and education level after controlling for race, UPDRS and OARS scores were significantly higher among patients who earned less than $30,000 per year than among those who earned more than $70,000 per year.
Similarly, low-income patients used newer dopaminergic agents significantly less often than did high-income patients (30% vs. 47%). Low-income patients, however, were more likely to be prescribed antidepressants, antipsychotics, and antidementia agents.
Newer dopamine agonists were prescribed significantly less often for patients with less than a college education (35%) than for those with a college education (43%).
In contrast, antipsychotics were approximately twice as likely to be prescribed for patients without a college education (8.4%) than they were for those with a college education (4.7%).
These findings reinforce the conclusion that racial disparities in the management of parkinsonism are not solely due to differences in income or education level, but that race itself is a significant independent factor, the researchers said.