Dr Viktor von Wyl Addresses the Impact of MS Disease Duration and Age on Disability Burden

Age is an important factor in the disease burden of multiple sclerosis (MS), as rising age both impacts disease course and brings with it additional risk of comorbidities. However, disease duration may be an even more important factor than age in reaching disability milestones, according to Viktor von Wyl, PhD, project leader, Epidemiology, Biostatistics and Prevention Institute, University of Zurich, Zurich, Switzerland.

Transcript

What did your research find with respect to how age and disease duration impact the disability burden of MS?

I’m working with the Swiss Multiple Sclerosis Registry, which is fairly representative of the population of persons with MS in Switzerland, and we had a special interest in finding out how these comorbidities and specific milestones are distributed across different age groups, but also across different strata of disease duration.

So we started out by a table that looks like a chess board; so in one dimension, you have age categories, and in the other, you have disease duration categories. We just looked at frequencies. So how frequently does hypertension occur in the Swiss population of MS?

Then, based on that, we already saw some patterns that were quite interesting. For instance, hypertension was really rising across the age dimension, but not so much across the MS disease duration dimension. Of course, that sparked our interest in looking into it in more detail, because eventually, this is information that is relevant to the clinicians because it tells us something about the disease burden of MS.

What we found was quite striking. Namely that the disability milestones, as expected, they correlate with disease duration, but only loosely with age. So we found actually that age was not so important up until the age of 60, when disability increases. So disability is measured mostly by the ability to walk, so there we found that this frequency spiked, but then became flat again.

But on the other hand, with disease duration, it was really more like a steady increase as would be expected, because this is one of the effects of multiple sclerosis. With other diseases, like comorbidities, we found that age was the main driver, whereas MS disease duration actually had no or only a small effect.

Now, what needs to be added is that other studies have found that, compared to the general population, MS actually increases the burden of comorbidities. So here, we only looked at the population of person who already have MS. But within this group, we didn’t find an effect of MS duration.