The development and initial validation of a telephone-administered cognitive test battery (TACT)

Abstract

Telephone interviews are increasingly recognized as a convenient assessment tool for epidemiologicai studies with geographically scattered samples, particularly where repeated assessments are to be made. We have compiled a telephoneadministered cognitive test battery (TACT) that aims to be sensitive enough to detect small but important degrees of early decline in cognitive function. The telephone-administered cognitive test battery comprises tests of crystallized intelligence, logical memory, visuo-spatial function, verbal fluency, and inductive reasoning. It incorporates a brief telephone assessment of cognitive status, the modified Telephone Interview for Cognitive Status (TICS-m), already validated as a screening test for dementia. We carried out a preliminary pilot study on 98 volunteer twin subjects. The test was generally administered in less than 30 minutes. Most component test scores were normally distributed with no evidence of ceiling or floor effects. We tested for the effects of age and education, and estimated test-retest reliability. A second-order factor analysis suggested that TACT measured three dimensions of cognitive /unction (I) logical memory, (2) crystallized intelligence and (3) the ability to learn and apply rules to abstract material under pressure of time. The last of these dimensions was the most influenced by age. The TACT is a convenient and efficient, yet comprehensive and demanding, measure of cognitive status with wideranging applications in gerontological epidemiology, genetic epidemiology and health service evaluative research.