Cost-effectiveness of PET in the diagnosis of Alzheimer disease.
OBJECTIVE
To evaluate the cost-effectiveness of positron emission tomography (PET) in the diagnosis of Alzheimer disease (AD) in community-dwelling patients with mild or moderate dementia who present to specialized AD centers.


METHODS
A decision-analytic model was used to compare costs and quality-adjusted life years (QALYs) associated with strategies involving single photon emission computed tomography (SPECT), dynamic susceptibility-weighted contrast material-enhanced magnetic resonance (MR) imaging, and PET as functional imaging adjuncts to the standard clinical work-up. Sensitivity analyses were performed to examine changes in test characteristics, health-related quality-of-life survey instruments, therapeutic effectiveness, and treatment rules.


RESULTS
The use of PET to confirm the results of the standard clinical work-up cost more but yielded fewer benefits than a strategy in which dynamic susceptibility-weighted contrast-enhanced MR imaging was substituted for the typically performed structural computed tomography. This relationship remained stable in scenarios in which standard diagnostic work-up accuracy, drug treatment effectiveness, and version of the Health Utilities Index were altered. Dynamic susceptibility-weighted contrast-enhanced MR imaging cost US dollars 598800 per QALY gained (range, US dollars 74400 to US dollars 1.9 million per QALY), compared with the cost of the standard diagnostic work-up. Treating all patients with dementia was the dominant imaging strategy, except when side effects in patients with non-AD-related dementia were modeled. In all scenarios, SPECT yielded fewer benefits than other strategies at a higher cost.


CONCLUSIONS
PET may have high diagnostic accuracy, but adding it to the standard diagnostic regimen at AD clinics would yield limited, if any, benefits at very high costs.
McMahon
Pamela M
PM
Institute for Technology Assessment, Massachusetts General Hospital, Zero Emerson Place, Suite 2H, Boston, MA 02114, USA.
Araki
Sally S
SS
Sandberg
Eileen A
EA
Neumann
Peter J
PJ
Gazelle
G Scott
GS
D000544:Alzheimer Disease / Q000175:diagnosis / Q000000981:diagnostic imaging*; D003362:Cost-Benefit Analysis; D003663:Decision Trees; D017048:Health Care Costs; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000191:economics; D019057:Quality-Adjusted Life Years; D014055:Tomography, Emission-Computed / Q000191:economics*; D015899:Tomography, Emission-Computed, Single-Photon / Q000191:economics