Construction of a Short Test of Aphasia on the Basis of Factor Analysis

Abstract

The purpose of the present investigation was to construct a short test of aphasia on the basis of factor analysis and to examine its clinical usefulness.As a first step, we performed the factor analysis of the test scores obtained from the administration of the long test to 180 consecutive patients, which resulted in the identification of the following factors; F1: Word Comprehension, F2: Language Behavior, F3: Phonological Processing, F4: Motor Functions of Speech Organs, F5: Visuomotor Ability, F6: Numerical Concept, F7: Calculation, and F8: Fluency.Secondly, in accordance with the rules of reducing the size of a test battery without transforming the factor structure of that battery, we reduced 56 subtests in the original version to 16.The test scores of the 180 patients on these 16 subtests, then, were put into another factor analysis. The results showed that the factor structure obtained with the shortened test was highly similar to that obtained with the original, longer battery.Examination of clinical usefulness of the shortened test in terms of its ability 1) to classify the patients into major clinical types and 2) to evaluate their severity levels indicated that the short test is quite similar to the original long test in both of these abilities.On the basis of these findings it was tentatively concluded that the new short test of aphasia was a useful tool for screening aphasic patients in a relatively short period of time (approx. 30 min.) as well as for malting a rough estimation on major clinical types and severity of aphasic impairments.