Infections and complications from severe disability are the greatest contributors to mortality among multiple sclerosis (MS) patients, according to a population-based study in British Columbia, Canada, which also found that that MS is a more common underlying cause of death among younger patients.
The study, “Causes that contribute to deaths due to multiple sclerosis: analyses of population-based multiple-cause-death data,” was presented Thursday at the 34th congress of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS), taking place through Friday in Berlin.
The data was presented by Keith Harding from the Institute for Psychological Medicine and Clinical Neuroscience, Cardiff University in the United Kingdom and Djavad Mowafaghian Centre for Brain Health, University of British Columbia in Canada.
The use of multiple-cause-of-death data — including the underlying and all contributing causes of death — has led to successful assessments of mortality causes in chronic diseases.
With the recent development of additional disease-modifying treatments for MS, better understanding of causes of death in these patients has become even more important.
To address this, the scientists explored the link between MS and all other causes listed on death certificates of adults in British Columbia between 1986 and 2013.
The International Classification of Diseases codes were classified into “underlying” (meaning the disease or injury that initiated the chain of events leading directly to death) or “any mention” (contributing) causes. Age, sex, and calendar year of death were accounted for in the analysis.
Results showed a total of 771,288 deaths over the period analyzed. The mean age at death was 74.5 years, with 47.5% being women.
MS was mentioned as a cause of death in 2,153 cases (0.28%), and was more commonly classified as the underlying cause in younger patients than in older ones, accounting for 78% in individuals younger than 40 and 49% in individuals older than 80.
When MS was mentioned in the certificates, the data revealed that urinary tract infection was the condition more likely to contribute to death, followed by aspiration pneumonia — which may occur when bacteria-containing pieces of food and drink enter the lungs — skin disease, respiratory infection, non-infectious respiratory disease, and other infections or sepsis (a potentially life-threatening complication of an infection).
Harding concluded in his presentation that “of death certificates that mentioned MS, MS was the underlying cause in 59 percent,” and that the disease “is more likely to be the underlying cause in those who are younger at death.”
“Deaths that were due to MS were commonly caused by infections and conditions that are complications of severe disability,” the team also concluded in the study.
They suggest that “interventions aimed at reducing the frequency and severity of these complications would be expected to improve survival in MS.”