A 60-year follow-up study of nearly 1,400 Norwegian patients with multiple sclerosis (MS) analyzed their survival and risk of dying starting with the onset of the disease through its progression.

The study, “A 60- year follow-up on survival and cause of death in multiple sclerosis in Western Norway,” was recently presented at the Americas Committee for Treatment and Research in Multiple Sclerosis (ACTRIMS) 2017 Forum, Feb. 23-25 in Orlando, Florida.

Researchers investigated the survival and causes of death in MS patients from Hordaland County in Western Norway who were followed from 1953 to 2013.

The analysis included data from 1,388 MS patients registered at Haukeland University Hospital in Bergen, Norway. Survival was adjusted for patients’ sex, age and disease course. Mortality and causes of death in the group were analyzed and compared to that of the general population.

Of the patients analyzed, 291 died — 56.4% of them due to MS. In the general population, the median time from disease onset to death was 55 years, while in the MS group the median age from disease onset to death was 41 years.

“Median life expectancy from onset in women with MS was 43 years compared to 56 years in the general female population, [and] 36 years in men with MS compared to 50 years in the general male population,” researchers wrote.

In patients with relapsing-remitting MS (RRMS) and those with primary progressive MS (PPMS), the median life expectancy from onset was 51 years and 26 years, respectively. Researchers observed that the risk of dying was higher in PPMS patients (3.9 value), while in patients with RRMS the value was 2.4. In the total MS population, the risk of dying was 2.7.

The risk of dying was also higher in women when compared to men, 2.9 vs. 2.5, respectively.

Patients also developing earlier symptoms (onset at age 20 years or younger) showed a higher risk of dying (7.3), a value that progressively decreased with disease onset later in life (4.0 for patients ages 21 to 30 years old; 2.6 for ages 31 to 40; and 1.3 for patients age 60 or older ).

Overall, “The 60-year follow-up on survival in MS showed a 14-year reduction in median life expectancy from onset. Mortality was almost threefold higher in MS patients; sevenfold higher among the youngest patients,” the researchers concluded. “Although female and young patients had longer median time to death compared to other patients, they had higher risk of dying compared to the general population.”

The decrease in mortality observed over the 60-year study period possibly suggests a significant impact in changes in environmental factors, including lifestyle and treatments.