Effects of dyskinesia in Parkinson's disease on quality of life and health-related costs: a prospective European study

The treatment of Parkinson's disease (PD) with l-DOPA leads to involuntary movements (dyskinesias). This 6-month observational study in three European countries in PD patients with various degrees of motor complications examined the effects of dyskinesias on the quality of life (QoL) of patients and health care costs. Retrospective and prospective health economic data were collected, and QoL of patients was measured using the Short Form-36 (SF-36) and the PD Quality of Life (PDQL) Scale. Regression analysis was used to estimate the adjusted effects of dyskinesias on QoL and costs, whilst accounting for the potentially confounding effects of disease progression, motor fluctuations and country. Increasing dyskinesia scores on either the Unified PD Rating Scale or the Goetz Dyskinesia Rating Scale were associated with significant reductions in QoL scores on the SF-36 and PDQL Scale. Increasing dyskinesia severity was also associated with increased depression scores on the Montgomery-Asberg Depression Rating Scale along with significant increases in health care costs. The effects of dyskinesia on QoL, depression and costs decreased but remained significant after adjustment for the confounding effects of disease progression and motor fluctuations. In conclusion, dyskinesias may adversely affect QoL and increase health care costs in patients with PD. Future studies should evaluate the potentially beneficial effects in terms of QoL and health care costs of strategies to delay the onset of, or the treatment of, dyskinesias.