Translation and Alternate Forms Reliability of the Visual Analogue Scale in the Three Major Nigerian Languages

Purpose: Our aims were to translate the anchors on the Visual Analogue Scale (VAS) into the three major Nigerian Languages and determine the adequacy of the alternate forms reliability of the VAS in these translations. Methods: The anchors on the VAS were translated into Yoruba, Igbo, and Hausa languages by linguistic experts and taken through back translation, clinical committee review, and pre–testing. Sixty–seven Hausa, 54 Igbo, and 165 Yoruba Knee/Hip OA patients were assessed on the original and translated versions of VAS. Scores on each translated anchor of the VAS were correlated with scores on the original VAS (anchors in English language) to assess the alternate forms reliability of the VAS in these translations. Results: The subjects 31 males, 134 females [Yoruba]; 17 males, 50 females [Hausa]; and 20 males, 34 females [Igbo] were aged 56.1 + 10.1, 54.3 + 6.4 and 52.8 + 13.9 years respectively. Significant positive correlations existed between each of the translated anchors and the original English Version [r = 0.63; P< 0.05 [Yoruba]; r = 0.98, P < 0.05 [Hausa]; r = 0.93; P< 0.05 [Igbo]. Conclusion: The VAS, when its anchors are translated into Yoruba, Hausa, and Igbo languages, is reliable and therefore recommended for use in the Nigerian clinical settings.