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

OASES-itsearviointilomakkeiden suomennosten validiteetti ja reliabiliteetti

The Overall Assessment of the Speaker´s Experience of Stuttering (OASESTM; Yaruss & Quesal,2016) is a patient-reported outcome measure that was designed to provide a comprehensiveassessment of “the experience of the stuttering disorder from the perspective of individualswho stutter” (Yaruss & Quesal, 2006, p. 90). The aim of the present study was to evaluate thevalidity and reliability of the authorized Finnish adaptations of the OASES-S (for school-agechildren, ages 7-12), OASES-T (for teens, ages 13-17), and the OASES-A (for adults ages18 and above). In this research, 60 school-aged children completed the OASES-S responseforms with 60 statements, 31 teenagers completed the OASES-T response forms with 80statements, and 31 adults completed the OASES-A response forms with 100 statements.The analyses of external (age), construct (correlation between different sections) and content(descriptive comparison between the Finnish and English OASES scores) validity indicatedthat the Finnish OASES questionnaires are valid measures. The age of the participant didnot have an effect on the results indicating good external validity. The mean scores weredescriptively close to those of the English version. Internal consistency and re-test reliabilitieswere high for both measures. The alpha scores of the OASES-S, OASES-T and OASES-Awere high (α 0,82–0,95) indicating good internal consistency. Similarly test-retest reliabilitydemonstrated high consistency of responses (r = 0,65–0,97) from one administration tothe next, except for the OASES-A Part I (General information). To conclude, the FinnishOASES-S, OASES-T and OASES-A validly and reliably measure the impact of stuttering onthe Finnish children, teenagers, and adults. The titles of the impact ratings may be changedto equal to the Finnish clinical terminology. Moreover, further research is needed on thecultural differences of the experience of stuttering and the assessment of the experience toget the measures more sensitive for different cultures.Overall Assessment of the Speaker´s Experience of Stuttering (OASESTM; Yaruss & Quesal, 2016) -itsearviointimenetelmä mittaa änkyttävän henkilön kokemuksia änkytyksestä hänen omasta näkökulmastaan. Tutkimuksemme tavoitteena oli arvioida alakouluikäisten OASES-S-, nuorten OASES-T- ja aikuisten OASES-A-itsearviointimenetelmän suomennosten pätevyyttä (validiteettia) ja luotettavuutta (reliabiliteettia). Tutkimuksessa 60 änkyttävää lasta täytti OASES-S:n (60 kysymystä), 31  änkyttävää nuorta OASES-T:n (80 kysymystä) ja 31 änkyttävää aikuista OASES-A:n (100 kysymystä). Mittareiden ulkoinen validiteetti, rakennevaliditeetti ja sisällön validiteetti todettiin hyväksi, joten itsearviointilomakkeet arvioivat pätevästi vastaajien kokemusta änkytyksen vaikutuksesta elämänlaatuun. Eri ikäisille suunnattujen itsearviointilomakkeiden alfakertoimet olivat korkeat (α 0,82–0,95) osoittaen hyvää sisäistä konsistenssia, ja mittaustulosten pysyvyys oli hyvä (r = 0,65– 0,97), lukuun ottamatta OASES-A:n osaa yleiset tiedot. Tutkimus osoitti, että suomennetut OASES-itsearviointilomakkeet erottelevat änkyttävien ihmisten kokemuksia änkytyksen vaikutuksesta heidän elämänlaatuunsa pätevyyden lisäksi luotettavasti. Vaikutuksen luokitukset olisi kuitenkin hyvä muuttaa suomalaisen kliinisen käytänteen mukaisiksi. Lisätutkimuksia tarvitaan kulttuurierojen vaikutuksesta änkytyksen kokemukseen ja sen itsearviointiin arviointimenetelmien sensitiivisyyden parantamiseksi