Health state values during the first year of drug treatment in early-stage Parkinson's disease: a prospective, population-based, cohort study.

backgroundParkinson's disease (PD) is a common neurodegenerative disorder in the elderly that may lead to both motor and non-motor symptoms with consequent severe impairment of quality of life. PD also represents a substantial economic burden on society because of the patient's decreased ability to work, increased need for care and need for costly treatment. Evaluation of quality-adjusted life-years (QALYs) is an important tool in cost-effectiveness analyses. To date, however, few data have become available about the utility gains or losses associated with the disease and its management.

objectivesTo evaluate the changes in health state values in patients with newly diagnosed PD during their first year of drug treatment, and to calculate the gain in QALYs and the incremental cost-effectiveness ratio (ICER) for this patient group.

methodsIn this prospective, population-based, cohort study, 199 patients with incident PD and 172 controls were followed over 1 year. Clinical data, drug use and utility scores obtained from the Short Form 6D (SF-6D) health state questionnaire were documented.

resultsPatients with PD had lower SF-6D utility scores than controls at baseline. Patients started on antiparkinsonian drugs had an improvement in mean utility scores of 0.039 from 0.667 to 0.706 (p < 0.05). The ICER was euros 45,259 (2007 values) per QALY, of which two-thirds consisted of the costs of drugs and one-third represented the costs of clinical consultations.

conclusionDrug treatment in patients with early-stage PD increases health state values, but the ICER is high. Further investigations will be necessary to capture the full consequences of treatment of PD and to evaluate the efficacy of disease management in this setting.