The validity and reliability of the Farsi version of "the overall assessment of the speaker's experience of stuttering– adult" (OASES-A) Questionnaire

Introduction: To apply a comprehensive evidence-based approach to stuttering, there is a need for an instrument examining the totality of this disorder. Yaruss and Quesal (2006) published the “Overall Assessment of the Speaker’s Experience of Stuttering” (OASES) questionnaire to achieve this aim. OASES-A can be used for documenting multiple treatment outcomes of individuals with stuttering who are older than 18 years. The aim of this study was to determine the validity and reliability of Farsi version of OASES-A questionnaire.Materials and Methods: Face validity, internal consistency and reliability of OASES-A were evaluated thorough conducting a pilot study in which a semi-structural interview arranged for 10 people who stutter (PWS). 50 PWS were then asked to complete modified OASES-A and S-24 scale to determine concurrent validity. Finally, in order to determine test-retest reliability of Farsi version of OASES-A questionnaire, 5 stuttering people completed the form 2 times within a 7-to-10-day interval.Results: Cronbach's alpha coefficient, which was calculated for entire 4 parts of the Farsi version of OASES, was 82 to 97, implying that the Farsi version of OASES-A questionnaire had a good concurrent validity, internal consistency and reliability. Finally it was shown that all the items of the questionnaire have an appropriate validity and reliability.Conclusion: Results of the present study indicate that the validity and reliability of Farsi version of OASES are compatible with the original English version.Keywords: OASES-A, Stuttering, Validity, Reliability, Outcome measurement, Adulthood stuttering