Translation and validation of the reduced Western Ontario and Mcmaster Universities Osteoarthritis Index (WOMAC) from English to Yoruba

Abstract

The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) developed in English language for assessment of knee osteoarthritis (KOA) may be misinterpreted among Yoruba-speaking patients. This study translated the reduced WOMAC into Yoruba and validated the translated copy with the original one. Sixty radiographically-confirmed knee osteoarthritic subjects in the south-west of Nigeria participated in this study. The original English version of the WOMAC was translated into Yoruba language (used as Yoruba version) by two linguists from the Department of Linguistic and African Languages, Obafemi Awolowo University, Ile-Ife, Nigeria. The Yoruba version was retranslated into English by the English Department of the same university to ensure accuracy. The original and retranslated questionnaires were administered to each subject at 3 days interval. After two weeks the retranslated questionnaire was administered to each subject. The data were analysed using descriptive and inferential statistics.

The results of validation showed that there were positive significant relationships between the scores for the original WOMAC and retranslated WOMAC in all the domains (pain; r=0.996, p<0.001, stiffness; r=0.971, p<0.001, difficulty r=0.980, p<0.001). The test retest reliability also showed a positive significant relationship (pain; r=0.996, p<0.001, stiffness; r=0.990, p<0.001, difficulty r=0.992, p<0.001) between the scores for the retranslated WOMAC at first administration and the scores when re-administered after 2 weeks in all the domains.

It can be concluded from the study that the Yoruba version of the reduced Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index is reliable and valid as an outcome measure for assessing patients with knee osteoarthritis.

Keywords: WOMAC, knee osteoarthritis, pain, stiffness and difficulty