title: Early versus delayed bilateral subthalamic deep brain stimulation for parkinson's disease: a decision analysis.
abstract: The long-term benefits of subthalamic nucleus deep brain stimulation (STN DBS) applied earlier in the disease course, before significant disability accumulates, remain to be determined. We developed a Markov state transition decision analytic model to compare effectiveness in quality-adjusted life years (QALYs) of STN DBS applied to patients with PD at an "early" ("off time" 10-20%) versus "delayed" stage ("off time" >40%). A lifelong time horizon and societal perspective were assumed. Probabilities and rates were obtained from literature review; utilities were derived using the time trade-off technique and a computer-assisted utility assessment software tool applied to a cohort of 22 STN-DBS and 21 non-STN-DBS PD patients. Uncertainty was assessed through one- and two-way sensitivity analyses and probabilistic sensitivity analysis using second-order Monte Carlo simulations. Early STN DBS was preferred with a quality-adjusted life expectancy of 22.3 QALYs, a gain of 2.5 QALYs over those with delayed surgery (19.8 QALYs). Early STN DBS was preferred in 69% of 5,000 Monte Carlo simulations. Early surgery was robustly favored through most sensitivity analyses. Delayed STN DBS afforded greater QALYs when using utility estimates exclusively from non-STN-DBS patients and, for the entire group, if the rate of motor progression were to exceed 25% per year. Although decision modeling requires assumptions and simplifications, our exploratory analysis suggests that STN DBS performed in early PD may convey greater quality-adjusted life expectancy when compared to a delayed procedure. These findings support further evaluation of early STN DBS in a controlled clinical trial.
authors.affiliation: Department of Neurology, Movement Disorders Center, The Neuroscience Institute, University of Cincinnati, Cincinnati, Ohio 45267-0525, USA. alberto.espay@uc.edu
authors.forename: Alberto J
authors.initials: AJ
authors.lastname: Espay
authors.forename: Jennifer E
authors.initials: JE
authors.lastname: Vaughan
authors.forename: Connie
authors.initials: C
authors.lastname: Marras
authors.forename: Rob
authors.initials: R
authors.lastname: Fowler
authors.forename: Mark H
authors.initials: MH
authors.lastname: Eckman
mesh_terms: D000368:Aged; D000978:Antiparkinson Agents / Q000627:therapeutic use; D003072:Cognition Disorders / Q000209:etiology / Q000523:psychology; D003661:Decision Support Techniques; D046690:Deep Brain Stimulation / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008390:Markov Chains; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications / Q000523:psychology / Q000628:therapy*; D011788:Quality of Life; D020531:Subthalamic Nucleus / Q000502:physiology*; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000978:Antiparkinson Agents