Complications related to disability affect MS-related mortality

Files containing medical records on a shelf in a medical clinic.

A study that analyzed information from death certificates issued in British Columbia over a nearly 30-year period has identified consistencies in records where multiple sclerosis (MS) was listed as a cause of death, offering clinically relevant insight into the reasons why people with MS have a shorter life expectancy on average than people who do not have MS.

"MS on its own is rarely fatal," said the study’s senior author Dr. Elaine Kingwell, epidemiologist and research associate in the division of neurology at UBC. "We wanted to understand what other factors might contribute to deaths due to MS by comparing the causes of these deaths to causes of other deaths that are not attributed to MS."

The study, published today in the journal Neurology, found that many of the contributing causes of death where MS was a factor could be related to frailty and inability to recover from illness such as pneumonia. However, death could also be due to complications of advanced disability and immobility including problems such as pressure ulcers and bladder infections. Overall, complications such as infections or respiratory illness contributed more frequently to deaths caused by MS than they did to deaths at a similar age that were not MS related.

"Many of the contributing conditions that were identified in this study could potentially be modifiable or preventable with interventions that slowed disability progression or reduced the severity of complications of disability," said Dr. Katharine Harding, the study’s first author and a neurologist at Royal Gwent Hospital, Wales.

The researchers accessed almost 800,000 death records with details of all adult deaths between 1986 and 2013 in British Columbia. Among these, they compared the 2,153 deaths where MS was mentioned as a cause with all remaining deaths.

British Columbia is one of the few places in the world where detailed population-based multiple-cause death data can be accessed. This allowed the team to investigate the underlying cause of death and up to 19 additional contributing causes for every death in the province, including all deaths attributed to MS, over the 28-year period.

"While there is evidence that survival has improved over time, life expectancy for people who have MS can still be six to ten years shorter than for people who don’t have MS," said Dr. Kingwell. "These study findings emphasize the importance of monitoring comorbidities in MS, and in managing disability progression to support greater mobility in later life."

Dr. Katharine Harding was a Postdoctoral Research Fellow in the Department of Neurology at UBC when the study was conducted and was supported by an MS of Society Canada Fellowship award. The study was coauthored by Dr. Helen Tremlett (Professor, Division of Neurology, UBC) together with colleagues at UBC. Funding for this study was provided by Canadian Institutes of Health Research and the US National MS Society.