Expanded Disability Status Scale (EDSS)

You might hear your neurologist talk about the Extended Disability Statues Scale (EDSS), or see it mentioned in MS research.  

What is the Expanded Disability Status Scale (EDSS)?

The Expanded Disability Status Scale (EDSS) is a way of measuring how much someone is affected by their MS. Neurologists use it to monitor changes in the level of someone’s disability over time.

The EDSS has a range from 0 to 10. Scores are in half unit steps – 3, 3.5, 4 and so on. The greater the level of disability, the higher the score out of ten.

Why is your EDSS score important?

EDSS scores are used to decide who can take part in clinical trials of many MS drugs. For example, people with scores over 6.5 haven’t in the past been able to take part in trials of disease modifying therapies (DMTs). But in some more recent trials, people with higher EDSS sores have taken part.

EDSS scores are also used to decide who can have disease modifying therapies (DMTs). For example, at the moment if your score is above 6.5 (that is, you use a wheelchair most of the time), then you don’t qualify to get a DMT. This is because studies in the past didn’t show these drugs had enough benefit once you were past this level of disability. But new trials are looking at this again.

Your EDSS score

Your neurologist will give you a score on the scale. It’s based on what he or she finds after examining you and asking you questions about how your MS affects you. The higher your score, the more MS is affecting you.

The score goes up by half a point with each step. But an increase of half a point or a whole point lower down the scale doesn’t represent as big an impact on your life as the same increase in the upper half of the scale. For example, going from 3 to 4 won’t be as big a change as going from 6 to 7.

Your score can change over time as the impact MS has on you changes. It usually goes up, although it can stay stable. For some people it might even go down a few points after they’ve had one of the harder-hitting DMT treatments. Most people never reach the upper end of the scale.

How is your EDSS score measured?

During an examination a neurologist will measure how MS is affecting how your body works. He or she will look at these ‘functions’:

  • muscle weakness and your ability to move your arms and legs
  • balance, coordination and tremor
  • eye movements you can’t control, your speech and swallowing
  • unusual sensations or numbness
  • your bowel and bladder
  • your eyesight
  • your thinking and memory
  • other functions

What do the points on the scale mean?

0.0 examination shows everything is normal

1.0 no disability, very small sign that one function isn’t normal

1.5 no disability, very small signs that more than one function isn’t normal

2.0 very small disability in one function

2.5 mild disability in one function or very small disability in two functions,

3.0 moderate disability in one function or mild disability in three or four functions. No problem walking

3.5 moderate disability in one function and mild or moderate disability in several other functions. No problem walking

4.0 significant disability but you can walk without an aid for 500 metres

4.5 significant disability but you’re up for much of the day. You can still work but might need some help. You can walk 300 metres without an aid

5.0 disability gets in the way of daily activities but you can walk without an aid for 200 metres

5.5 disability rules out full daily activities. You can walk 100 metres without an aid

6.0 you can walk 100 metres with a stick or crutch, with or without rests

6.5 you can walk 20 metres with the two aids (crutches or sticks) without stopping for rests

7.0 essentially you must use a wheelchair but are active all day. You can’t walk more than 5 metres even with an aid

7.5 you can only take a few steps. You use a wheelchair and may need help getting in and out of it. You may need a motorised wheelchair

8.0 basically you need to be in a chair, wheelchair or bed. You may be out of bed much of the day. You can use your arms

8.5 basically in bed much of the day. You still have some use of your arms

9.0 in bed all the time but you can communicate, eat or swallow

9.5 in bed but you can’t communicate, eat or swallow

10 death due to MS

What your EDSS measures … and doesn’t measure

The EDSS scale focuses a lot on how MS affects your walking. It also looks at problems with your bladder, bowel, eyesight and balance, swallowing and speech difficulties, and numbness and strange sensations you might feel. It also looks at how MS affects your muscles, and your memory and thinking.

Many people think that EDSS scores aren’t the best measure of how MS affects people overall. For example, it doesn’t include some symptoms that you can’t see. These include pain, fatigue and depression. It also doesn’t pay much attention to how MS affects how well you can use your arms, hands and fingers. It also doesn’t reflect well how the effects of MS can change from day to day, week to week or over a longer time.