Economic and Health-Related Quality of Life Considerations of New Therapies in Parkinson's Disease

The progressive disability of Parkinson's disease results in substantial burdens for patients, their families and society in terms of increased health resource use, poorer quality of life, caregiver burden, disrupted family relationships, decreases in social and leisure activities, deteriorating emotional well-being, and direct and indirect costs of illness. Health-related quality of life (HR-QOL) measures have been used successfully in cross-sectional studies to identify and characterise these burdens; however, there is not yet substantial evidence that these instruments will be responsive to changes in patients over time and that the results will provide patients and health professionals with clinically meaningful information useful in making decisions about treatment strategies. The few studies documenting direct and indirect costs indicate increased use of ancillary health and community services, significant adaptations in home and transportation, increased use of mobility and self-care aids, and lack of access to appropriate healthcare providers. Patients with Parkinson's disease incur higher hospital expenses, have increased number of prescriptions, and experience earnings loss; the latter also applies to family caregivers. The choice, intensity and timing of therapy are determined by a variety of factors: presenting symptoms, age, employment status, comorbidity, cognitive impairment and level of functional impairment. Choices must be individually tailored to a patient's physical and personal needs. To be useful for patients with Parkinson's disease in clinical practice, clinicians should be able to use HR-QOL measures to identify appropriate medical interventions or socio-behavioural modifications to modify the HR-QOL deficits. However, while the interplay of interventions and clinical outcomes are often well understood, the effects of interventions on HR-QOL outcomes have not been studied extensively. Little research has been done that explicitly links the signs and symptoms of Parkinson's disease to the HR-QOL outcomes. The only Parkinson's disease cost-effectiveness study as yet performed indicated higher costs for patients receiving pramipexole than for those not taking the drug, but additional quality life-years were gained. Longer term effectiveness of many treatment strategies, and the usefulness of HR-QOL instruments to assess these treatments for individual patients over time, are critical areas for future research.