Diagnosing Apraxia of Speech in Children and Adults When There Is No Gold Standard: A Scoping Review About the Diagnostic Process.

PURPOSE: Childhood apraxia of speech (CAS), stroke-induced apraxia of speech (AOS), and progressive apraxia of speech (PAOS) cannot be diagnosed with an error-free gold standard test or measure. Reference standards are sensible approximations but are vulnerable to bias. In this scoping review, we characterize the diagnostic process for reference standards that have been used in recent diagnostic literature and evaluate the extent to which bias-reducing strategies have been implemented.

METHOD: We extracted data about the diagnostic process for studies of speech characteristics in CAS, AOS, and PAOS that were published between 2014 and 2024. Observational studies published in peer-reviewed journals and in English were included, whereas treatment studies, surveys, case studies, and reviews were excluded.

RESULTS

Of 198 included studies, the most common diagnostic method was consensus or confirmation by two to three diagnosticians (38.4%), followed by checklist verification (25.3%), and simple clinical impression (19.2%). Testing or measurement techniques were used less frequently for diagnostic purposes (9.6%). The diagnostic process varied by etiology, and strategies to reduce bias were minimally implemented across the board.

CONCLUSIONS

There is a need to accept that current diagnostic reference standards are inherently imperfect and to reduce risk of bias by using converging evidence, defining syndrome features operationally, standardizing consensus formation, and estimating reliability of classification. A focus shift to how speech profiles, tests, and measures relate directly to prognosis and treatment response may expedite scientific discovery, as may strategy-sharing among those who work with children, adult stroke survivors, and adults with progressive disease.

SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.31173799.