Apraxia of speech: how reliable are speech and language therapists' diagnoses?
OBJECTIVE
To discover how reliably speech and language therapists could diagnose apraxia of speech using their clinical judgement, by measuring whether they were consistent (intra-rater reliability), and whether their diagnoses agreed (inter-rater reliability).


METHODS
Video clips of people with communication difficulties following stroke were rated by four speech and language therapists who were given no definition of apraxia of speech, no training, and no opportunity for conferring.


METHODS
Videos were made of people following stroke in their homes. Ratings of the videos were carried out in the university lab under controlled conditions.


METHODS
Forty-two people with communication difficulties such as aphasia, apraxia of speech and dysarthria took part, and four specialist speech and language therapists acted as raters.


METHODS
Speech and language therapists' ratings of the presence and severity of apraxia of speech using videos.


RESULTS
Intra-rater reliability was high for diagnosing (1) the presence of apraxia of speech (Cohen's kappas ranging from 0.90 to 1.00; 0.93 overall), and (2) the severity of apraxia of speech (kappa 0.84 to 0.92; 0.90 overall). The inter-rater reliability was also high for both the presence of apraxia of speech (kappa 0.86) and severity of apraxia of speech (0.74).


CONCLUSIONS
Despite controversy over its nature and existence, specialist speech and language therapists show high levels of agreement on the diagnosis of apraxia of speech using their clinical judgement.
Mumby
Katharyn
K
Central Cheshire PCT.
Bowen
Audrey
A
Hesketh
Anne
A
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001072:Apraxias / Q000145:classification / Q000175:diagnosis* / Q000209:etiology; D003147:Communication Disorders / Q000145:classification / Q000175:diagnosis* / Q000209:etiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D012720:Severity of Illness Index; D013066:Speech-Language Pathology; D020521:Stroke / Q000150:complications; D006113:United Kingdom; D014743:Videotape Recording