Authors' results and conclusions: Because of population aging, dementia is becoming a growing health problem, which impacts greatly on public health. Dementia diagnosis is based on clinical assessment, and imaging tests such as computed tomography are used to evaluate some of its causes. It has been postulated that positron emission tomography (SPECT) would allow early diagnosis of Alzheimer-type dementia and other types of dementia; thus contributing to the differential diagnosis of atypical cases. For this report, diagnostic studies, prognosis, economic analyses and coverage policies about the use of SPECT in dementia were evaluated. Thirty-two diagnostic studies which evaluated SPECTs precision were included. Most had poor quality designs to assess diagnostic tests. The best quality studies reported a diagnostic precision similar to that obtained with clinical assessment by experienced physicians or specialized centers, and lower than that reported in lower quality studies (70.4% weighted average sensitivity vs. 91.8%; 82.1% weighted average specificity vs. 88.3%, respectively). Most of the studies considered clinical diagnosis as the reference test. As regards the prognostic value, the abnormalities observed with SPECT did not add any information to that obtained during clinical assessment. One study did not find SPECT useful to discriminate the group of patients who will respond to pharmacological treatment. The cost-effectiveness analyses evaluated did not consider the use of SPECT as a cost-effective alternative, neither for all dementia patients nor for possible or probable Alzheimer's dementia based on clinical criteria. This was because SPECT did not give a precise diagnosis, and the correct identification of dementia subtypes did not improve long-term results since there are no clearly effective treatments. The systems analysed do not cover this test or they do so for previously clinically assessed patients whose diagnosis is, however, still uncertain, or for dementias of atypical presentation.

Authors' recommendations: We could conclude that up until now, SPECT has not clearly demonstrated its usefulness in assessing patients with dementia, and it has no precise indications for diagnosis, evaluation of prognosis or monitoring response to treatment.

Authors' methods: Overview

Project Status: Completed

URL for project: http://www.iecs.org.ar/

Year Published: 2004

English language abstract: An English language summary is available

Publication Type: Not Assigned

Country: Argentina

Organisation Name: Institute for Clinical Effectiveness and Health Policy

Contact Address: Dr. Emilio Ravignani 2024, Buenos Aires - Argentina, C1414 CABA

Contact Name: info@iecs.org.ar

Contact Email: info@iecs.org.ar

Copyright: Institute for Clinical Effectiveness and Health Policy (IECS)