Deep brain stimulation in the treatment of Parkinson's disease - A cost-effectiveness analysis

Background: In treating PD, deep brain stimulation (DBS) has shown great pr omise in a series of uncontrolled studies. Objective: To estimate the incre mental cost effectiveness of DBS compared with the best medical management in late-stage PD. Methods: The authors constructed a decision model to dete rmine the lifetime incremental cost effectiveness between two options in pa tients with PD aged 50 years and older: 1) best medical management and 2) D BS. As the long-term efficacy of DBS (>3 years) is not known, key assumptio ns regarding the procedure's long-term durability were made. Costs were in US 2000 dollars, and quality-adjusted life year (QALY) was the effectivenes s measure. Base assumptions were that quality of life (QOL) in patients wit h late-stage PD is 0.55 (0-to-1 scale, 1 is perfect health) and that DBS be nefits are constant for 4 years, eroding gradually over the next 5 years un til at parity with those produced by best medical management. Incremental c ost-effectiveness and sensitivity analyses were performed. Results: Under b ase-case assumptions, DBS provides an additional 0.72 QALY at an additional cost of $35,000 compared with best medical management that results in an i ncremental cost-effectiveness ratio (C/E) of $49,000. QOL increases of betw een 18 and 30% resulted in questionable cost effectiveness. QOL increases o f between 6 and 18% resulted in incremental C/E ratios not usually consider ed cost effective (> 100,000/QALY). Conclusions: The results suggest that D BS may be cost effective in treating PD if QOL improves 18% or more compare d with those receiving best medical management. This underscores the need f or randomized, controlled, prospective DBS experiments including QOL and ec onomic components.