Prospective comparative study on cost-effectiveness of subthalamic stimulation and best medical treatment in advanced Parkinson's disease



This is an open, prospective, longitudinal study designed to compare two cohorts of patients with advanced Parkinson's disease during 1 year, one undergoing bilateral subthalamic stimulation (STN-DBS) and the other receiving the best medical treatment (BMT), with respect to the clinical effects observed and the medical expenses produced. Assessments were done by using clinical measures and a generic health related quality of life scale. A questionnaire was used to collect direct healthcare resources. As a measure of cost-effectiveness, we calculated life years gained adjusted by health-related quality of life (QALY) and the incremental cost-effectiveness ratio (ICER). Clinical and demographic variables of both groups were comparable at baseline. Total UPDRS scores improved from 50.5 ± 3.6 to 28.5 ± 3.8 in STN-DBS patients and worsened from 44.3 ± 3.3 to 54.2 ± 4 in the control group. Pharmacological costs in the operated patients were 3,799 ± 940€, while in the BMT group the costs were 13,208 ± 4,966€. Other medical costs were 1,280 ± 720€ in the STN-DBS group and 4,017 ± 2,962€ in BMT patients. Nondirect medical costs were 4,079 ± 1,289 in operated patients and 2,787 ± 1,209€ in the BMT group. Mean QALYs were 0.7611 ± 0.03 in STN-DBS and 0.5401 ± 0.06 in BMT patients. In STN-DBS patients, the ICER needed to obtain an improvement of one point in the total UPDRS score was of 239.8€ and the ICER/QALY was of 34,389€. Cost-effectiveness parameters were mostly related to the degree of clinical improvement and the reduction of pharmacological costs after STN-DBS. An ICER of 34,389€/QALY is within appropriate limits to consider subthalamic stimulation as an efficient therapy. © 2007 Movement Disorder Society