Difficulties in using Oswestry Disability Index in Indian patients and validity and reliability of translator-assisted Oswestry Disability Index

Abstract

Background and aim of the study: In Indian patients, in view of language plurality and illiteracy, self-reporting of English version of Oswestry Disability Index (ODI) is not practical. Our study aim was to find out to what extent self-reporting of ODI was possible and in cases where self-reporting was not possible, to see validity and reliability of a translator-assisted ODI score.

Materials and methods: Fifty patients with low backache and who could not use the English version were assessed with ODI with the use of two translators at a gap of 3 h in a test and retest manner. Patients were also asked to report the most important disabling activity in their day-to-day life.

Results: A total of 58 questionnaires were filled during the study period out of which eight patients (14%) self-reported English version; while 50 patients needed a translator. The Cronbach's alpha between two translators for the ODI scores of 50 patients was 0.866, but aggregate of difference between two scores for each ODI component shows high difference between two translators for question nos. 3, 9, and 10. Cronbach's alpha was best when item no. 3 was deleted (0.875, translator 1; 0.777, translator 2). Thirty-seven people did not answer the question related to sexual activity. Agreement between two values was assessed using Kendall's tau and was found good (0.585, Spearman's coefficient 0.741). Kendall's tau values correlating total ODI score and individual components show that all the items move together, but correlation was poor for question no. 3 (P value 0.16 for translator 2).

Conclusions: Translator-assisted ODI is a good outcome assessment tool in backache assessment in places where validated local language versions are not available, but in Indian patients, inclusion of question nos. 3 and 8 related to weight lifting and sexual function needs to be reviewed.

Fig. 1

Shows the aggregate of difference between two translators in each of ODI components

Fig. 2

Shows the difference between two translators and average between two translators. (lines above and below 0 mark are set at 5 points and dots above +5 and −5 line indicate difference of more than 5 points between two translators)