Authors' objectives:

This report aims to assess the benefits for positron emission tomography (PET) scanning in patients with dementia, in patients with mild cognitive impairment and in asymptomatic patients with a family history of Alzheimer's disease (AD), subsequent to the standard evaluation as described in the American Academy of Neurology (AAN) guidelines.

Authors' recommendations: Based on a comprehensive literature review, meta-analysis and decision analysis, there are four major conclusions regarding the use of PET in patients who may have AD: 1. For patients with dementia who have had a recommended clinical evaluation, treatment without further testing is superior to treating based on an additional test using PET. Since treatment for this clinical scenario has been shown to be moderately effective and relatively benign, the increase in true negatives (i.e. those who did not need the treatment) resulting from use of PET is overshadowed by the concomitant increase in false negatives (i.e. those who would benefit from the treatment, but for whom it would be withheld if they were not identified as positives). 2. If the evidence for treatment efficacy of AChE-I agents in patients with dementia can be extrapolated to patients with MCI, then empiric treatment of these patients would also be superior to treating based on PET. This is because the proportion of MCI patients with AD is comparable to and may be higher than the proportion of demented patients with AD. Even if survival is not improved, earlier treatment should improve the proportion of time a patient is alive with a lesser degree of impairment. 3. If the evidence for treatment efficacy of AChE-I agents in patients with dementia can be extrapolated to patients who are asymptomatic but have an elevated risk for AD, then empiric treatment of these patents would be superior to treating based on PET. 4. PET scanning could be of value if a new treatment were to be developed tha was more effective but had a risk of one or more of a variety of highly negative consequences such as a reduction in quality of life, inducing progression of disease, or death.

Authors' methods: Systematic review

Project Status: Completed

URL for project: http://www.cms.hhs.gov/coverage/8b3-ww.asp

Year Published: 2001

English language abstract: An English language summary is available

Publication Type: Not Assigned

Country: United States

Organisation Name: Agency for Healthcare Research and Quality

Contact Address: Center for Outcomes and Evidence Technology Assessment Program, 540 Gaither Road, Rockville, MD 20850, USA. Tel: +1 301 427 1610; Fax: +1 301 427 1639;

Contact Name: martin.erlichman@ahrq.hhs.gov

Contact Email: martin.erlichman@ahrq.hhs.gov

Copyright: Agency for Healthcare Research and Quality (AHRQ)