Time between expanded disability status scale (EDSS) scores.Zurawski J, Glanz BI, Chua A, Lokhande H, Rotstein D, Weiner H, Engler D, Chitnis T, Healy BC. Mult Scler Relat Disord. 2019 Feb 5;30:98-103.
BACKGROUND: Although the expanded disability status scale (EDSS) is the most commonly used measure of disability for multiple sclerosis, measurement of disability accumulation is complex due to the unequal steps of the scale.
OBJECTIVE: To estimate the time between EDSS scores in a large MS cohort from a single center and determine the impact of functional system scores on EDSS transitions.
METHODS: 31,394 clinical visits with EDSS scores from 2054 subjects in the CLIMB longitudinal cohort study were included in our analysis. The time to each EDSS score and the time between each EDSS score were calculated using the nonparametric maximum likelihood estimate for interval censored data. For each initial EDSS value, the association between functional status scores and subsequent EDSS value was assessed using a mixed effects linear regression model, and the association with time to EDSS increase was assessed using a Cox proportional hazards model.
RESULTS: The median (middle) time until EDSS 2, 3, 4, 5 and 6 in all subjects were 4.8, 15.1, 28.2, 31.2, and 32.4 years, respectively. The time intervals showed that the disability accumulation intervals from EDSS 4 to 6 were much shorter than the accumulation intervals from EDSS 0 to 3 or from EDSS 6 to 8. For EDSS of 1 or 1.5, pyramidal, cerebellar, sensory, bowel-bladder and mental system scores were associated with higher subsequent EDSS values. For higher EDSS values, only pyramidal and bowel-bladder scores maintained the association.
CONCLUSIONS: Time between specific EDSS levels varies considerably. Certain functional system scores have greater predictive power for future EDSS-related disability despite same present EDSS level. These findings will assist in adaptation of the EDSS as an outcome measure to assess MS-related disability in clinical trials.
All in all this says why EDSS is a rather rubbish outcome measure, and its use has held up progress.
However the regulators are wedded to this like some third arm. This scale is insensitive to change, it is biased to detect movement disability and is non-linear and slow.
If you want to do a progressive EDSS trial, load the trial up with EDSS 4-6 and you may get an answer the quickest, don’t do this and you will wait and wait.
EDSS over 6 and you may be waiting for some time. The proof is in the pudding. THC (tetrahydrocannabinol-the active ingredient of cannabis) was not effective in pwMS above EDDS6, because in the trial the control group did not progress.
Look at people below EDSS 5.5 and you had a positive trial. Yes a positive trial, and you would have a neuroprotective for progressive MS now.
People are looking for neuroprotectives to trial and here is one that works….but it is being ignored. Because all tpeople remember is the failure to affect the EDSS
It is amazing that the good and the great in the British MS world cannot see this, and this positive effect has been disregarded at least twice. I can only put it back on the agenda so many times… I despair.
Maybe ProfG and DrF can save they day. Otherwise you will have fluoxetine 2 and we all know where fluoxetine 1 went…yep 5 years and a few million wasted going nowhere.
Ibudilast showed something in progressive MS, because it showed something in progressive