Telephone validation of an Urdu translated version of the extended disability severity scale in multiple sclerosis...

Expanded Disability Status Scale (EDSS) is a commonly used tool to assess the extent of functional impairment in multiple sclerosis (MS) patients for clinical and research purposes. EDSS is traditionally conducted in a face-to-face setting, however, routine in-person EDSS assessments are often difficult to perform in developing countries due to the various reasons patients are unable to access healthcare and maintain clinic visits. Hence validating a locally translated telephone-based EDSS (T-EDSS) could be potentially useful to both physicians and patients by removing the need to commute to healthcare centers for disability assessment and could lead to overall improved care for MS patients.

Firstly, the EDSS scale was translated and culturally adapted into Urdu. On enrolment, EDSS was conducted during scheduled clinic visits and forty-seven subjects with MS were henceforth included in the study. Same patients were contacted via telephone following two weeks by a different neurologist to carry out the telephone-EDSS assessment. The patients' baseline EDSS scores at enrolment were blinded to prevent interviewer bias.

Kappa value for agreement between the two assessments for EDSS scores of more than 6 was 0.73, whereas the kappa value for EDSS score of less than 4.5 was 0.35. The intraclass correlation coefficient (ICC) for T-EDSS score < 4.5 was 1.7, and for a score > 4.5 was 4.9, with the overall ICC being 0.64. Cronbach's alpha value for T-EDSS score < 4.5 was 0.59 and for the score > 4.5 was 0.79.

This study shows that there exists a positive correlation and substantial level of agreement between in-person EDSS and T-EDSS, especially in MS patients with higher baseline EDSS scores. Hence a locally translated T-EDSS can be used in Pakistani MS patients with reasonable confidence. T-EDSS may be more useful in MS patients with moderate to severe disability.