Entwicklung und Validierung eines Tests zur Früherkennung der Demenz mit Depressionsabgrenzung (TFDD)1

Abstract

Psychometric tests used for the early detection of dementia often are seen as too difficult or too complex. Classical neuropsychologic tests were not developed for this purpose. Sensitivity and specificity to discriminate "healthy" vs. "ill" are low. For measuring both dementive and depressive symptoms, so far no test has been published. The objective of this study was to develop a sensitive and specific test for dementia that is easy to administer and to evaluate. Moreover, it should discriminate dementia from depressive pseudodementia. With respect to former studies, items were selected that recognized patients in the beginning of the disease. Additionally, depressive symptoms were rated. With the items for dementia, 88 patients with dementia of the Alzheimer type, 52 patients with depressive disorder and 37 healthy elderly controls were investigated. In this group of already diagnosed patients, the test reached a sensitivity and specificity of 100 percent (healthy elderly controls vs. patients with Alzheimer's disease: n = 125, U = 0, p < 0.001; patients with depressive disorder vs. patients with Alzheimer's disease: n = 140, U = 0, p < 0.001; healthy elderly controls vs. patients with depressive disorder: n = 89, U = 485.5, p < 0.001). For the dementia items, the inter-rater-reliability was rs = 0.996 (p < 0.001, n = 18), for the depression items it was rs = 0.753 (n = 18, p < 0.001). The test-retest-reliability was rs = 0.868 (p < 0.001, n = 35) for the dementia items and rs = 0.7 (n = 8, p < 0.05) for the depression items. These validation data will make the test useful for practitioners. Its ability to discriminate patients suffering from dementia of the Alzheimer type from healthy controls is comparable to tests consuming more time.

EEG and the Test for the Early Detection of Dementia with Discrimination from Depression (TE4D): a validation study

“…In the same study, the accuracy of the diagnosis made with EEG-data was 93.8%. For the TE4D alone, similar data were found (Ihl et al, 2000a). The data confirming a correlation of EEG and psychometric tests improve the knowledge regarding the validity of tests.…”

“…One of the most important differences is their sensitivity to detect dementia and also their user friendlyness. For the TE4D high sensitivity and specificity were found (Ihl et al, 2000a) and compared to the other tests investigated here, the administration takes only a few minutes of time, the amount of material needed is low and the handling of the test is easy.…”

“…Internal consistency was ¼ 0.834, test-retest reliability r s ¼ 0.868 and inter-rater reliability r s ¼ 0.996 (Ihl et al, 2000a). First studies comparing the TE4D with established psychometric tests like the Alzheimer's Disease Assessment Scale (ADAS-cog, Mohs et al, 1983, Rosen et al, 1984, Ihl and Weyer, 1993, Brief Cognitive Rating Scale (BCRS, Reisberg et al, 1983a,b;1985;Reisberg and Ferris, 1988;Froelich, 1991) Syndrom-Kurz-Test, (SKT, Erzigkeit, 1989;Erzigkeit et al, 1989Erzigkeit et al, , 1993 and Mini-Mental-State-Examination (Folstein et al 1975;Kessler et al, 1990) underlined its convergent validity.…”

“…The Test for the Early Detection of Dementia with Discrimination from Depression (TE4D see Table 1, Ihl et al, 2000a) was developed as a screening instrument to identify dementia. It was constructed to improve sensitivity and specificity in the detection of early dementia as well as ease in applicability compared to already existing tests.…”

Quantitative EEG in progressing vs stable mild cognitive impairment (MCI): results of a 1‐year follow‐up study

“…For psychometric testing, the Test for the Early Detection of Dementia with Differentiation from Depression (Test zur Früherkennung der Demenzenmit Depressionsabgrenzung--TFDD; Ihl and Grass-Kapanke, 2000), the cognitive subscale of the Alzheimer Disease Assessment Scale (ADAS cog; Rosen et al, 1984), the Mini-Mental-StatusExamination (MMSE; Folstein et al, 1975) and the Trail Making Test (TMT-A and -B; Reitan, 1979) were administered. For the assessment of the activities of daily living, the Bayer Activities of Daily Living scale (B-ADL; Hindmarch et al, 1998) was applied, for the registration of depressive symptoms the Montgomery Asberg Depression Rating Scale (MADRS; Montgomery and Asberg, 1979) was used.…”