Can the Expanded Disability Status Scale be assessed by telephone?

Mult Scler. 2003 Mar;9(2):154-9. doi: 10.1191/1352458503ms884oa.


Information from patients who are unable to continue their visits to a study centre may be of major importance for the interpretation of results in multiple sclerosis (MS) clinical trials. To validate a questionnaire based on the Expanded Disability Status Scale (EDSS), patients in five different European centres were assessed independently by pairs of trained EDSS raters, first by telephone interview and a few days later by standardized neurological examination. Seventy women and 40 men with an average age of 43.7 years (range 19-74 years) were included in the study. Mean EDSS score at the last visit was 4.5 (0-9). EDSS assessment by telephone was highly correlated with the EDSS determined by physical examination (Pearson's correlation coefficient = 0.95). An intraclass correlation coefficient (ICC) of 94.8% was found for the total sample; 77.6% and 86%, respectively, for patients with EDSS < 4.5 (n = 46) and > 4.5 (n = 64). Kappa values for full agreement were 0.48; for variation by +0.5 steps and +1.0 steps, 0.79 and 0.90, respectively. Best agreement could be found in higher EDSS scores, where assessment by telephone interview might be needed most. The telephone questionnaire is a valid tool to assess EDSS score in cases where the patient is unable to continue visiting a study centre or in long-term follow-up of trial participants.

Publication types

  • Multicenter Study
  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Adult
  • Aged
  • Disability Evaluation*
  • Europe
  • Female
  • Humans
  • Interviews as Topic / methods*
  • Interviews as Topic / standards
  • Male
  • Middle Aged
  • Multiple Sclerosis / diagnosis*
  • Reproducibility of Results
  • Walking