impairments in memory function. Standard AD treatment
provides marginal improvements in this domain. Recent
reports, however, suggested that deep brain stimulation
(DBS) may result in improved memory. Given significant
equipment costs and health expenses required for DBS
surgery, we determine clinical and economic thresholds
required for it to be as effective as standard AD treatment.
Literature review yielded annual AD progression probabilities,
health-related quality of life (QoL), and costs by
AD stage. Our 5-year decision analysis model compared
cumulative QoL in quality-adjusted life years (QALYs) and
costs of standard therapy to theoretical DBS treatment of
various success rates, using known complication rates and
QoL data. The base case was a patient with mild-stage AD.
DBS success was defined as regression to and maintenance
of minimal stage AD, which was defined as midway between
mild and no dementia, for the first year, and continuation
of the natural course of AD for the remaining
4 years. Compared to standard treatment alone, DBS for
mild-stage AD requires a success rate of 3 % to overcome
effects of possible surgical complications on QoL. If DBS
can be delivered with success rates above 20 % ($200 K/
QALY) or 74 % ($50 K/QALY) for mild AD, it can be
considered cost-effective. Above a success rate of 80 %,
DBS treatment is both clinically more effective and more
cost-effective than standard treatment. Our findings
demonstrate that clinical and economic thresholds required
for DBS to be cost-effective for AD are relatively low.