The Applicability of the Clinical Features of English Childhood Apraxia of Speech to Cantonese: A Modified Delphi Survey.

Purpose Childhood apraxia of speech (CAS), a motor-based speech disorder, has been well studied in English contexts. However, there is a limited understanding of the applicability of its features to other languages. Thus, this study sought to determine the applicability of the features identified in the English CAS literature to Cantonese CAS. Method A two-round modified Delphi survey of experts was used to identify the clinical features of CAS in Cantonese speakers. Ten Cantonese-speaking qualified speech therapists were recruited as experts. In Round 1, the experts were asked an open-ended question about the clinical features of Cantonese CAS. In Round 2, the experts were asked to rate the importance of the proposed clinical features for making differential diagnoses of Cantonese CAS on a 5-point Likert scale ranging from 1 (very important) to 5 (not important at all). Results In Round 1, the expert panel identified 79 clinical features in nine domains. Sixty-two features (78.5%) were consistent with English CAS. Three English features were not identified in this study, while three features specifically related to Cantonese phonology were identified. In Round 2, 29 clinical features across six domains were found to meet the statistical criteria and were therefore regarded as important for making differential diagnoses of CAS among Cantonese speakers. Conclusions The results suggest that the clinical features identified in the English CAS literature are applicable to Cantonese CAS. The consistency of the findings implies that core and possible co-occurring features are shared between English and Cantonese CAS. The six features that were not common in both languages were discussed. Further investigation of CAS in and between different languages is recommended. This study is not the end point. Future studies can empirically examine the lexical tones or pitch variations to develop a possible objective measure for CAS.