Impact of Parkinson's disease and its pharmacologic treatment on quality of life and economic outcomes.

The impact of Parkinson's disease (PD) and its pharmacologic treatment on health-related quality of life (HRQL) and economic outcomes is reviewed. PD is a chronic and progressive neurologic disorder characterized by specific motor deficits resulting from the degeneration of dopaminergic neurons in the substantia nigra. The cardinal symptoms are tremor, rigidity, bradykinesia, and loss of postural reflexes. PD markedly reduces HRQL and places an economic burden on society of up to $25 billion per year. Patients' inability to move freely and to perform everyday tasks restricts their independence and leads to increased reliance on caregivers and assistive devices. Emotional and psychosocial well-being is also negatively affected. As the disease progresses, the response to levodopa typically decreases and various motor complications develop; these are difficult to treat and result in further declines in HRQL. The economic costs of PD include both direct health care costs (for drugs, physician services, and hospitalization) and indirect costs (for lost worker productivity). Economic analyses of PD and its treatments can help guide effective allocation of health care resources. Various antiparkinsonian agents and formulations, such as extended-release levodopa-carbidopa and pramipexole, have been found to be cost-effective relative to other agents. The newest antiparkinsonian drugs, cathechol-O-methyltransferase inhibitors, also have the potential to improve HRQL and economic outcomes, although more study is needed to confirm this. The total impact of PD and its treatment can be fully appreciated only when HRQL and economic outcomes, in addition to clinical outcomes, are examined.