“In response to the following question on my post on ‘what does your neurologist look for when (s)he looks in your eyes?‘ we have decided to let our web-EDSS go live for you to use.
‘There is plenty of criticism on this blog and other sites about how poorly the EDSS reflects the impact that a person’s MS has on their functioning. Will the web-EDSS you are developing simply replicate the current EDSS with all of its short-comings or will it be some sort of positive step in a different direction?’
“The takehome message is that the EDSS done as part of routine clinical practice is simply not reliable in most MS Centres. Having a proxy, i.e. the web-EDSS, bypasses the need to ask your neurologist to do the EDSS. Maybe you disagree?”
“Once you have your EDSS what do you do with it? You can use it to monitor your disease or you may want to use it to assess your prognosis. The last abstract below describes the so called MS Severity Scale (MSSS). This uses your disease duration (time since onset of your disease) and the EDSS to see where you rank yourself on a scale from zero to ten (0-10) compared to other MSers. The higher your score the worse off you are. I have taken these scores from the MSSS data file (version 3) and put them into a table for you to look-up your MSSS.”
“In addition to assessing and/or monitoring your MS and working out how severe your MS is the web-EDSS could provide a cheap and easy way to do new studies including a proxy for the EDSS. The web-EDSS may allow us to gradually get rid of the EDSS from future studies; why do both the physician and web-EDSS; the physician EDSS is expensive? Surely the web-EDSS will be sufficient?”
“Where to from here? We are already working on improving version 1 of the web-EDSS. We are planning to expand the range of 6.0 – 8.0 by making it more granular. At present the scale goes up in 0.5 increments; we feel the way we have asked questions in such a way as to make this part of the scale more detailed; we are proposing 0.25 or 0.2 point increments. We are also working on including better walking distance estimates as part of the calculator to make it much more accurate as a walking scale. We are very aware that people are very poor at estimating their real walking distance. Another weakness of the web-EDSS is knowing about your neurological examination. At present we recommend that you ask your neurologist if your neuro exam is abnormal; for example do you have pallor of the optic disc, do you have abnormal reflexes, etc. In the future we plan to build in tools that will allow a self-assessment of some of these hard to get at neurological assessments. In other words we would like the web-EDSS to be completely independent of neurologists. Now wouldn’t that be nice?”
Leddy et al. Validating a novel web-based method to capture disease progression outcomes in multiple sclerosis. J Neurol. 2013 Oct;260(10):2505-10.
Background: The Expanded Disability Status Scale (EDSS) is the current ‘gold standard’ for monitoring disease severity in multiple sclerosis (MS). The EDSS is a physician-based assessment.
Roxburgh et al. Multiple Sclerosis Severity Score: using disability and disease duration to rate disease severity. Neurology. 2005 Apr 12;64(7):1144-51.
METHODS: Using data from two large longitudinal databases, the authors tested whether cross-sectional disability assessments are representative of disease severity as a whole. An algorithm, the Multiple Sclerosis Severity Score (MSSS), which relates scores on the Expanded Disability Status Scale (EDSS) to the distribution of disability in patients with comparable disease durations, was devised and then applied to a collection of 9,892 patients from 11 countries to create the Global MSSS. In order to compare different methods of detecting such effects the authors simulated the effects of a genetic factor on disability.
RESULTS: Cross-sectional EDSS measurements made after the first year were representative of overall disease severity. The MSSS was more powerful than the other methods the authors tested for detecting different rates of disease progression.
CONCLUSION: The Multiple Sclerosis Severity Score (MSSS) is a powerful method for comparing disease progression using single assessment data. The Global MSSS can be used as a reference table for future disability comparisons. While useful for comparing groups of patients, disease fluctuation precludes its use as a predictor of future disability in an individual.