Clinical applicability and cutoff values for an unstructured neuropsychological assessment protocol for older adults with low formal education

• Published in: PloS one Vol. 8; no. 9; p. e73167
• Main Authors: de Paula, Jonas Jardim, Bertola, Laiss, Ávila, Rafaela Teixeira, Moreira, Lafaiete, Coutinho, Gabriel, de Moraes, Edgar Nunes, Bicalho, Maria Aparecida Camargos, Nicolato, Rodrigo, Diniz, Breno Satler, Malloy-Diniz, Leandro Fernandes
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 16-09-2013; Public Library of Science (PLoS)
• Subjects: Activities of daily living; Adults; Aged; Aged, 80 and over; Aging; Alzheimer Disease - diagnosis; Alzheimer's disease; Auditory discrimination learning; Bias; Biomarkers; Caregivers; Cognition Disorders - diagnosis; Cognitive ability; Dementia; Dementia disorders; Design; Diagnostic systems; Ecological monitoring; Education; Educational Status; Elderly patients; Factor analysis; Female; Geriatrics; Humans; Impairment; Laboratories; Male; Medical research; Neuropsychological Tests - standards; Older people; Patients; Quantitative psychology; Sensitivity and Specificity; Spatial memory; Studies; Validity; Visual perception; Brazil; Rio de Janeiro Brazil
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0073167

The neuropsychological exam plays a central role in the assessment of elderly patients with cognitive complaints. It is particularly relevant to differentiate patients with mild dementia from those subjects with mild cognitive impairment. Formal education is a critical factor in neuropsychological performance; however, there are few studies that evaluated the psychometric properties, especially criterion related validity, neuropsychological tests for patients with low formal education. The present study aims to investigate the validity of an unstructured neuropsychological assessment protocol for this population and develop cutoff values for clinical use.
A protocol composed by the Rey-Auditory Verbal Learning Test, Frontal Assessment Battery, Category and Letter Fluency, Stick Design Test, Clock Drawing Test, Digit Span, Token Test and TN-LIN was administered to 274 older adults (96 normal aging, 85 mild cognitive impairment and 93 mild Alzheimer`s disease) with predominantly low formal education. Factor analysis showed a four factor structure related to Executive Functions, Language/Semantic Memory, Episodic Memory and Visuospatial Abilities, accounting for 65% of explained variance. Most of the tests showed a good sensitivity and specificity to differentiate the diagnostic groups. The neuropsychological protocol showed a significant ecological validity as 3 of the cognitive factors explained 31% of the variance on Instrumental Activities of Daily Living.
The study presents evidence of the construct, criteria and ecological validity for this protocol. The neuropsychological tests and the proposed cutoff values might be used for the clinical assessment of older adults with low formal education.