Data: MS cases up worldwide, but disease-related deaths are down
Analysis finds 'important shifts in the global landscape' over 30 years
Over the past three decades, the number of adults worldwide being diagnosed with multiple sclerosis (MS) has increased, but globally, rates of death related to complications of MS have declined, a new study shows.
“The period from 1990 to 2021 has witnessed important shifts in the global landscape of multiple sclerosis,” the researchers wrote. “The overall picture is one of a growing burden, but also meaningful progress: Patients are being diagnosed earlier, living longer, and — in many cases — achieving better control of disease activity than in the past.”
The researchers attributed the drop in MS-related deaths worldwide to advances in medical care, most notably the development of new treatments for the neurodegenerative disease.
They noted, however, that “the gender disparity” in MS — the disease predominantly affects females versus males — has increased over the last 30 years.
“Globally, women now outnumber men roughly 3 to 1 among MS patients,” the team noted.
The study, “Emerging epidemiological trends of multiple sclerosis among adults aged 20-54 years, 1990-2021, with projections to 2035: a systematic analysis for the global burden of disease study 2021,” was published in the journal Frontiers in Neurology. The work was done by scientists from the 920th Hospital of the Joint Logistics Support Force of the People’s Liberation Army in China.
MS is a chronic disorder in which the immune system attacks healthy tissue in the brain and spinal cord. MS itself is generally not fatal, but it causes disability and increases the risk of life-threatening complications like pneumonia.
Over the last three decades, MS care has evolved radically: The 1990s saw approvals of the first disease-modifying therapies (DMTs) proven to slow the progression of MS, and more recent years have seen the advent of DMTs with more potency as well as other advances in MS treatment.
Analyzing global trends in MS diagnoses, deaths from 1990 to 2021
To learn more about how epidemiological and mortality data have shifted over the decades, and to assess the disease’s impact worldwide, the research team analyzed global MS trends between 1990 and 2021.
In 2021, the researchers noted, there were nearly 52,000 people diagnosed with MS around the world, and more than 4,700 deaths related to MS complications, according to the data. Over the decades prior, the incidence of MS — that is, the number of people newly diagnosed with the disease — has tended to increase.
The researchers highlighted several potential explanations for the increase in MS incidence, including changes in demographic and lifestyle habits. They also noted that part of this increase may reflect improved access to diagnosis, especially in less wealthy parts of the world.
“Part of the observed global rise in MS (especially in places like India or Latin America) may reflect closing the diagnostic gap,” the researchers wrote.
MS rates are highest in Europe and North America, but rates have also increased in other parts of the world where MS has historically been considered rare, the researchers noted.
“The disease’s reach has extended into regions previously thought to be largely unaffected, underscoring that MS is a global health concern and not merely a Western problem,” they wrote.
Researchers cite improvements in MS diagnosis, treatment
Among patients, the researchers noted that more women continue to be diagnosed with MS than men.
Indeed, “this gap has widened in recent decades,” the team wrote, noting that “the increasing incidence of MS over the late 20th century was largely driven by rising cases in women.”
One of the most positive trends in MS epidemiology [study of the disease among a population] is the declining mortality [number of deaths] and slowing disability progression, attributable to advances in medical care.
But even though worldwide incidence rates of MS have increased, the researchers found that rates of death from complications of MS were markedly lower in the early 2020s compared with the 1990s.
Further, the data also indicate that patients in the 2020s generally have less severe disability than did people with MS in the 1990s. These changes likely reflect improvements in medical care for MS, the researchers said.
“One of the most positive trends in MS epidemiology is the declining mortality and slowing disability progression, attributable to advances in medical care,” the researchers wrote.
The scientists noted that although rates of death and disability have declined worldwide, there have still been increases in some parts of the world, particularly in less-wealthy regions.
Overall, these data “highlight a complex global landscape of MS, characterized by fluctuating incidence and improving mortality and [disability] trends, albeit with notable regional disparities,” the team concluded.
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