The validity and realiability of the Finnish versions of the OASES patient-reported outcome measures

Authors

• Eira Jansson-Verkasalo Dept. of Psychology and Speech-Language Pathology, University of Turku
• Auli Laiho Stuttering Resource Center Tempo
• J.S. Yaruss Communicative Sciences and Disorder, Michigan State University, East Lansing, MI

DOI: https://doi.org/10.23997/pk.113859

Keywords:

assessment methods, OASES, quality of life, stuttering

Abstract

The Overall Assessment of the Speaker´s Experience of Stuttering (OASES^TM; Yaruss & Quesal,
2016) 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). The aim of the present study was to evaluate the
validity and reliability of the authorized Finnish adaptations of the OASES-S (for school-age
children, ages 7-12), OASES-T (for teens, ages 13-17), and the OASES-A (for adults ages
18 and above). In this research, 60 school-aged children completed the OASES-S response
forms with 60 statements, 31 teenagers completed the OASES-T response forms with 80
statements, 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 indicated
that the Finnish OASES questionnaires are valid measures. The age of the participant did
not have an effect on the results indicating good external validity. The mean scores were
descriptively close to those of the English version. Internal consistency and re-test reliabilities
were high for both measures. The alpha scores of the OASES-S, OASES-T and OASES-A
were high (α 0,82–0,95) indicating good internal consistency. Similarly test-retest reliability
demonstrated high consistency of responses (r = 0,65–0,97) from one administration to
the next, except for the OASES-A Part I (General information). To conclude, the Finnish
OASES-S, OASES-T and OASES-A validly and reliably measure the impact of stuttering on
the Finnish children, teenagers, and adults. The titles of the impact ratings may be changed
to equal to the Finnish clinical terminology. Moreover, further research is needed on the
cultural differences of the experience of stuttering and the assessment of the experience to
get the measures more sensitive for different cultures.