Category Fluency as a Screening Test for Alzheimer Disease in Illiterate and Literate Patients

Abstract

Brief cognitive tests are widely used for dementia screening, but are usually influenced by education. The present work aimed to determine education-adjusted cut-off scores and correspondent sensitivity (S) and specificity (Sp) values of the category fluency (CF) test (animals/min) as a screening tool for Alzheimer disease (AD). Eighty-eight patients with mild AD and 117 normal matched controls were evaluated. Patients and controls were divided into 4 groups according to educational level (illiterates, 1 to 3, 4 to 7, and > or =8 y) and were administered the CF test. In each group, cut-off values were determined using Receiver Operator Characteristic analysis. The areas under Receiver Operator Characteristic curves were 0.922/0.914/0.963/0.954, for the identification of AD among the groups of illiterates, 1 to 3, 4 to 7, and > or =8 years of education, respectively. The cut-off points for each group were 9 (S=90.5% and Sp=80.6%) for illiterates; 12 (S=95.2%% and Sp=80.0%) for 1 to 3 years; 12 (S=91.3% and Sp=91.9%) for 4 to 7 years, and 13 for those with > or =8 years (S=82.6% and Sp=100.0%). These results suggest that the CF may be a useful screening test for mild AD in different educational levels, with the need of using specific cut-off scores adjusted for each range of schooling.

Frontal assessment battery in a Brazilian sample of healthy controls: normative data

“…As described before, these items are influenced by schooling 13,14 . We did not observe a correlation between the subtest "Motor series" and education, which has been previously described 15 .…”

Phonological and semantic verbal fluency: a comparative study in hearing-impaired and normal-hearing people

“…The relationship between education and the number of words evoked in verbal fluency tasks has been broadly studied, being shown in healthy normal-hearing individuals, in the elderly, and in subjects with various pathologies (5,10,11,(17)(18)(19) . The best performance in normal-hearing individuals in relation to the hearing-impaired people would be expected due to the greater difficulty of the former in acquiring and updating the lexical and the reduction in the number of auditory experiences, which is reflected in a reduced vocabulary (6) .…”

“…The SVF was analyzed through elocution, in 1 min, with words of the "animal" semantic class. This category is the most widely used in this test, and it is highly sensitive for the evaluation of access and semantic organization of the mental lexicon (10) . Participants received the following instruction: "Tell me as many animals as you can remember, any kind of animal is valid," and the time was recorded by the researcher.…”

Educational bias in the assessment of severe dementia: Brazilian cutoffs for severe Mini-Mental State Examination

“…For instance, brief cognitive tests such as the category fluency (CF test) 24 and the Cambridge Cognitive Examination (CAMCOG) 25 are widely used for dementia screening, but may require new cutoff values for patients with low schooling. Both studies included wide samples, but none of them included severely impaired AD patients.…”