荒木 謙太郎

INTRODUCTION: Evaluation of multiple domains, such as language, articulation, and cognitive function, is frequently required in neurological communicative disorders. The purpose of this study was to investigate the performance of a 10-min screening scale for estimating aphasia, dysarthria, and cognitive dysfunction using a multicenter, large-sized consecutive series. METHODS: We conducted a multicenter validation study that included 314 patients with brain injury between February 1 and June 31, 2018, from 20 medical centers across Japan. The Screening Test for Aphasia and Dysarthria (STAD) was developed in Japan in 2009, and a previous smaller-scale retrospective study established its high to moderate validity. All patients had undergone the STAD, and 212 of them underwent the Western Aphasia Battery or Assessment of Motor Speech for Dysarthria. The effect size on all 29 items and receiver operating curves of 3 sections of the STAD were analyzed based on external criteria, which were decided considering the clinical diagnosis of aphasia, dysarthria, and cognitive dysfunction. Correlations between the STAD and reference tests were calculated. RESULTS: The phi coefficients of 23 out of 29 items exceeded the moderate effect size of 0.3 toward the targeted disorder. Overall, there was a good balance between sensitivity (82-92%) and specificity (77-78%), with moderate to large positive and negative likelihood ratios (3.7-4.19 and 0.1-0.23). The Pearson's r between the verbal section and Western Aphasia Battery Aphasia Quotient, the articulation section and Assessment of Motor Speech for Dysarthria, and the nonverbal section and Western Aphasia Battery Nonlinguistic Skills were 0.89, 0.70, and 0.79, respectively. CONCLUSION: We demonstrated that the STAD has acceptable content and concurrent validity for the assessment of communicative function in patients with brain injury. This short screening tool can be useful in specific contexts, such as in early bedside investigations, to obtain a quick summary of communicative function prior to the administration of other tests, and in cases where more in-depth testing is not feasible.