The Factor Structure of the Boston Diagnostic Aphasia Examination, Third Edition

The Boston Diagnostic Aphasia Examination (BDAE) is one of the most commonly used aphasia batteries. The newest edition has undergone significant revisions since its original publication in 1972, but existing evidence for its validity is lacking. We examined the construct validity of BDAE-3 and identified the factor structure of this battery.

A total of 355 people with aphasia of various types and severity completed neuropsychological evaluations to assess their patterns of language impairment. A principal component analysis with varimax rotation was conducted to examine the components of BDAE-3 subtests.

Five components accounting for over 70% of the BDAE-3 total variance were found. The five language factors identified were auditory comprehension/ideomotor praxis, naming and reading, articulation-repetition, grammatical comprehension, and phonological processing.

Our results show that the BDAE-3 demonstrates good construct validity, and certain language functions remain primary, distinct language domains (i.e., receptive vs. expressive language) across severities of aphasia. Overall, our findings inform clinical practice by outlining the inherent structure of language abilities in people with aphasia. Clinicians can utilize the findings to select core BDAE-3 tests that are most representative of their respective functions, thereby reducing the total testing time while preserving diagnostic sensitivity. (JINS, 2019, 25, 772-776).