A Systematically Conducted Scoping Review of the Evidence and Fidelity of Treatments for Verb Deficits in Aphasia: Verb-in-Isolation Treatments.

Abstract

Purpose Aphasia research demonstrates increasing interest in the treatment of verb retrieval deficits. This systematically conducted scoping review reports on the level and fidelity of the current evidence for verb treatments; on its effectiveness regarding the production of trained and untrained verbs, functional communication, sentences, and discourse; and on the potential active ingredients. Recommendations to guide clinical decision making and future research are made. Method The computerized database search included studies from January 1980 to September 2018. The level of evidence of each study was documented, as was fidelity in terms of treatment delivery, enactment, and receipt. Studies were also categorized according to the treatment methods used. Results Thirty-seven studies were accepted into the review, and all but 1 constituted a low level of evidence. Thirty-three studies (89%) described treatment in sufficient detail to allow replication, dosage was poorly reported, and the fidelity of treatment was rarely assessed. The most commonly reported treatment techniques were phonological and semantic cueing in 25 (67.5%) and 20 (54%) studies, respectively. Retrieval of trained verbs improved for 80% of participants, and improvements generalized to untrained verbs for 15% of participants. There was not sufficient detail to evaluate the impact of treatment on sentence production, functional communication, and discourse. Conclusions The evidence for verb treatments is predominantly of a low level. There are encouraging findings in terms of treatments being replicable; however, this is tempered by poor monitoring of treatment fidelity. The quality of verb treatment research would be improved by researchers reaching consensus regarding outcome measures (including generalization to, e.g., sentences and discourse) by manualizing treatment to facilitate implementation and exploring the opinions of participants. Finally, while treatment is largely effective in improving production of trained verbs, lack of generalization to untrained items leads to the recommendation that personally relevant verbs are prioritized.