Mortality in PD dictated by other health issues
MedWire News: Patients with Parkinson's disease (PD) have an increased mortality risk, yet other serious conditions dominate their healthcare needs in the final year of life, report researchers.
Indeed, patients considered to have terminal PD were most often hospitalized for cardiovascular or infectious diseases, with PD very rarely mentioned as a cause of hospital admission.
The findings arise from an analysis of 138,000 Medicare beneficiaries with incident PD who were followed up from 2002 through 2008.
"Our methods also allowed us to identify potential areas of improvement in the care of patients with PD by identifying illnesses temporally associated with death," say Allison Willis (Washington University School of Medicine, St Louis, Missouri, USA) and colleagues.
Overall, 64% of patients died during follow up, which the team says is similar to the mortality risk in patients with myocardial infarction, hip fracture, and Alzheimer's disease. The adjusted risk for death was 26% lower in women than men, was reduced 14% and 28% in Hispanics and Asians, respectively, relative to White patients, and rose with advancing age.
Around three-quarters of the PD patients were hospitalized at least once during their final year of life, yet PD was listed as a primary illness for just 1.1% of those hospitalized. Patients were most often hospitalized for infection (20.9%), cardiovascular disease (18.5%), and noninfectious pulmonary disease (12.8%).
The researchers suggest that the management of PD symptoms may dominate patients' routine healthcare visits. "This may lead to less-aggressive screening for or treatment of other common illnesses," they write in the Archives of Neurology.
"Additionally, physicians and patients alike may attribute nonspecific symptoms such as fatigue, weakness, or exercise intolerance to PD when they in fact represent other illnesses such as subacute cardiopulmonary disease."
Dementia occurred in 69.6% of the cohort, most often in women (71.5%) and African‑Americans (78.2%). The researchers comment that this pattern also occurs in Alzheimer's dementia, which could imply either increased susceptibility or a "unique pathophysiologic course" for dementia in African‑Americans and women with PD.
Dementia had a major impact on survival, raising patients' mortality risk 1.72-fold, after accounting for confounders.
"Our data highlight the need for prevention of or treatment for dementia in patients with PD because of its effect on survival," say Willis et al.
Mortality was increased among patients living in urban versus rural areas and, among urban-based patients, mortality was further increased in those living in areas with high levels of manganese release.
The researchers caution that they lacked lifetime exposure estimates, but suggest that ongoing environmental exposure may need to be accounted for in future clinical trials.
By Eleanor McDermid