Psychometric Properties of Translated Knee Outcome Survey–Activities of Daily Living Scale from English to Yoruba Language among Patients with Knee Pathologies

Abstract

Introduction: The study translated the Knee Outcome Survey–Activities of Daily Living Scale (KOS‑ADLS) from English to Yoruba language and established the reliability and validity of Yoruba version with the original English version.
Methods: Seventy‑four patients with knee pathologies in selected hospitals, South West Nigeria, participated in the study. The original version of KOS‑ADLS was translated to Yoruba by two Linguists from Obafemi Awolowo University, Ile‑Ife, whose mother tongue is Yoruba. The Yoruba version was retranslated by another specialist in English Language, but the mother tongue is Yoruba from the English Department of the same university. The original KOS‑ADLS questionnaire was administered to each participant, and 3 days later, the translated KOS‑ADLS questionnaire was readministered. After 2 weeks, a copy of the Yoruba translated version was readministered to each participant. The data collected were analysed using descriptive and inferential statistics. Alpha level was set at 0.05.
Results: There were 67.6% of females participants, and 70.2% were fluent in both Yoruba and English languages. The concurrent validity of translated KOS‑ADLS shows a significant relationship between original and translated versions of symptoms (r = 0.828, P < 0.001) and functional limitation (r = 0.973, P < 0.001). There was a significant relationship between each of the score of symptoms (r = 0.969, P < 0.001) and functional limitation (r = 0.983, P < 0.001) of translated KOS‑ADLS and score of Yoruba retranslated KOS‑ADLS. Intra‑class correlation of the test–retest was 0.813 and the Cronbach’s alpha was 0.897.
Conclusion: It can be concluded that there was a strong relationship between the Yoruba and original versions of KOS‑ADLS in all domains and test–retest reliability was very strong.