Psychometric evaluation of the Dutch translation of the Overall Assessment of the Speaker’s Experience of Stuttering for adults (OASES-A-D)

Abstract: The Overall Assessment of the Speaker’s Experience of Stuttering for adults (OASES-A; Yaruss & Quesal, 2006, 2010) is a patient-reported outcome measure that was designed to provide a comprehensive assessment of “the experience of the stuttering disorder from the perspective of individuals who stutter” (Yaruss & Quesal, 2006, p.90). This paper reports on the translation process and evaluates the psychometric performance of a Dutch version of the OASES-A. Translation of the OASES-A into Dutch followed a standard forward and backward translation process. The Dutch OASES-A (OASES-A-D) was then administered to 138 adults who stutter. A subset of 91 respondents also evaluated their speech on a 10-point Likert scale. For another subset of 45 respondents, a clinician-based stuttering severity rating on a 5-point Likert scale was available. Thirty-two of the respondents also completed the Dutch S-24 scale (Brutten & Vanryckeghem, 2003). The OASES-A-D showed acceptable item properties. No ceiling effects were observed. For 30 out of 100 items, most of which were in Section IV (Quality of Life), floor effects were observed. Cronbach’s alpha coefficients for all sections and subsections surpassed the 0.70 criterion of good internal consistency and reliability. Concurrent validity was moderate to high. Construct validity was confirmed by distinct scores on the OASES-A-D for groups with different levels of stuttering severity as rated by the speakers themselves or by clinicians. These results suggest that the OASES-A-D is a reliable and valid measure that can be used to assess the impact of stuttering on Dutch adults who stutter.