Health-Related Quality of Life and Healthcare Utilisation in Patients with Parkinson's Disease: Impact of Motor Fluctuations and Dyskinesias

Idiopathic Parkinson's disease (PD) is a common chronic progressive neurodegenerative disorder associated with the progressive loss of dopaminergic neurons in the substantia nigra. The natural course of the disease may lead to severe disability despite a variety of pharmacological and surgical treatment options. Levodopa is still the most effective symptomatic treatment for PD; however, long term use can cause a number of adverse effects including motor complications, nausea and vomiting, postural hypotension and changes in mental status. The onset of motor complications marks a crucial point in the management of PD. They may present as changes between akinetic and mobile phases (motor fluctuations) or as abnormal involuntary movements (dyskinesias). After levodopa treatment for 3 to 5 years, motor complications occur in approximately 50% of patients, and after 10 years in >80% of patients. Treatment options have recently expanded as new drugs have been licensed and surgical procedures refined. Patients with motor complications present a demanding task in disease management, and often multiple drugs and high dosages are necessary to achieve only suboptimal control, resulting in increased healthcare utilisation. Costs increase considerably in patients with motor fluctuations and dyskinesias compared with patients without these symptoms. In a French study, 6-month direct medical costs per patient increased from 1648 euros (EUR) to EUR3028 in patients without and with motor fluctuations, respectively. In a recent French study a significant difference in monthly direct medical costs was found in patients with and without dyskinesias (EUR560 vs 170). Unfortunately, no data are available on the effect of motor complications on indirect costs. Several studies have shown that health-related quality of life (HR-QOL) is reduced when motor fluctuations occur. This may also be true of dyskinesias, but because of the limited number of studies a definite conclusion is not yet possible. Recently, surgical treatment options have been used to deal with advanced PD and late stage complications. Although their effect on motor complications and HR-QOL is well documented, they result in increased costs (total medical cost: EUR28920) compared with drug treatment alone and are increasingly restricted by healthcare providers. The purpose of this article is to review the available data from pharmacotherapeutic, surgical and economic studies on HR-QOL and healthcare expenditure in patients with PD, with a major focus on the impact of motor fluctuations and dyskinesias.