Validation of a translated version of the modified Japanese Orthopedic Association (mJOA) cervical myelopathy score in an Arabic speaking population

Abstract

Introduction: Degenerative Cervical Myelopathy (DCM) is a growing disorder. Standardization of its assessment tools is an integral part of its management. The modified Japanese orthopedic association (mJOA) score is one of the most commonly used tools. Currently, there is no available Arabic translated version of any cervical myelopathy functional score. This study aimed to translate, culturally adapt, and measure the psychometric properties of an Arabic translated version of the mJOA. Methods: After translation of the score using the standard forward-backward translation procedure, a validation study including 100 patients was carried out from June 2019 to June 2020. The following psychometric properties were measured: feasibility, reliability, internal consistency, validity, minimal clinically important difference (MCID), ceiling, and floor effect. Results: No problems were encountered during the process of translation and cross-cultural adaptation of the score. The mJOA-AR was found to be a feasible score. It showed high inter-observer reliability (r = 0.833, P < 0.001), test-retest reliability (r = 0.987, P < 0.001) and good internal consistency using Cronbach's alpha (0.777) and Pearson interclass correlation coefficient (r = 0.717). The score showed good convergent and divergent construct validity correlating it to the Arabic validated version of the neck disability index (NDI). The mJOA-AR had an MCID of 1.506. Both the ceiling and floor effects of the total score and the first and second domains were within the acceptable range, while the third and fourth domains had a high ceiling effect (30% and 39%, respectively). Discussion: Our translated version of the mJOA score was found to be a feasible score with acceptable psychometric properties. This score can be utilized as a good outcome measure tool in Arabic-speaking countries.