Changes in Complete Utterances Following Communication-Based Group Treatment for Chronic Aphasia

Background: Evidence suggests that communication-based aphasia group treatment may increase formal assessment scores and improve features of discourse production. The real-life interactions which occur during group treatment may increase use of grammatically complete and relevant utterances. Aims: To examine the effects of communication-based group treatment on production of complete utterances during structured and conversational discourse in adults with chronic aphasia. Methods & Procedures: We analyzed structured and conversational discourse samples from 23 adults with chronic aphasia originally collected by Elman and Bernstein-Ellis (1999a). Bayesian generalized linear mixed-effects models were used to evaluate changes in use of complete utterances and its two components, syntactic completeness and relevance, at treatment exit and 4-6 weeks post-treatment. Outcomes & Results: Results are presented with reference to the region of practical equivalence (ROPE, i.e., the range of effect sizes small enough to ignore) and in terms of the probability, derived from Bayesian model posterior distributions, that the effect in question exceeded, fell within, or fell below the ROPE. At the group level, syntactic completeness improved in structured discourse, but syntactic completeness, relevance, and complete utterances did not change during conversational discourse. Individual response to treatment varied and participants with mild aphasia and without concomitant apraxia of speech were more likely to demonstrate post-treatment change in complete utterances. Conclusions: Use of syntactically complete utterances during structured discourse increased at treatment exit and follow-up. Participants, especially those with severe aphasia and apraxia of speech, may have changed in ways not revealed by the complete utterance measure.