A report in the January issue of Archives of Neurology, one of the JAMA/Archives journals, reveals that demographics and clinical factors seem to be linked to survival in patients with Parkinson disease (PD), and that the presence of dementia is linked to a substantial increase in mortality.
Background information in the article says that even though Parkinson disease is a common neurodegenerative disease amongst elderly people, the data on the survival rates of Parkinson’s patients is contradictory.
Allison W. Willis, M.D., from Washington University School of Medicine, St. Louis, and team carried out a nationwide retrospective cohort study of 138,000 Medicare beneficiaries with incident Parkinson disease. The patients were identified in 2002 with a follow-up until the end of 2008.
The researchers observed that sex and race “significantly predicted” survival rates amongst patients. They established that Hispanics, Asian, or women across all ethnic groups, displayed a lower adjusted mortality risk compared with white men. 64% of Parkinson’s patients died during the six-year study. The researchers noted that black patients had the highest approximate death rate with 66.4%, followed by 64.6% of white patients, 55.4% of Hispanic patients and 50.8% of Asian patients.
Findings revealed that by the end of the study period, 69.9% of the study participants were diagnosed with dementia. The highest prevalence of dementia was identified in black patients with 78.2% incidences and Hispanics with 73.1% respectively. The prevalence of dementia amongst white and Asian patients with PD was lower but comparable with 69% vs. 66.8%, respectively.
The researchers observed that the mortality risk in patients suffering from both Parkinson disease and dementia was greater than in those without dementia. They also noted that patients with terminal Parkinson disease were frequently hospitalized for cardiovascular disease and infection, yet seldom for Parkinson disease. The findings indicate that Parkinson patients living in urban high industrial metal emission areas have a marginally higher adjusted risk of mortality. The researchers believe further studies are required to better determine what impact environmental exposure may have on Parkinson disease and/or survival.
They conclude:
“We demonstrate that dementia occurs commonly in patients with incident PD 65 years and older; this had the strongest effect on age-adjusted survival among the variables that we studied. Our data highlight the need for prevention of or treatment for dementia in patients with PD because of its effect on survival.”
Written by Petra Rattue