Survival and Cause of Death in the British Columbian Multiple Sclerosis Population

Multiple sclerosis (MS) is a relatively common neurological disease. Because of its chronic nature and because it typically first appears in people in their mid 20s to 30s, people with MS are usually expected to live for many years following disease onset. Little is known about survival expectations, predictors of long-term survival, how survival is influenced by MS drug therapies, and causes of death in this population. Ever since immunomodulatory therapies first became available to Canadian MS patients in the mid 1990s, there has been a rapid uptake of these drugs. These medications appear to be at least partially effective in modifying some aspects of the disease, such as relapses, but they are associated with significant side effects, require frequent injections, and are expensive. The long-term impact of treatment is unknown and opportunities to study treatment-naïve patients have diminished over the years, as there are fewer patients with MS who have not taken these therapies. In British Columbia, we have a valuable data resource that includes both unexposed (untreated) and treated MS patients.

Dr. Elaine Kingwell is combining several large, powerful, clinical and administrative longitudinal datasets, including the population-based BC MS clinical database (containing data from approximately 7,000 MS patients over a 30-year period), BC Ministry of Health medical services plan registration data, BC Vital Statistics death data and BC Cancer Agency data. She will use this data set to determine the long-term health impacts of MS and how they are influenced by immunomodulatory drugs. She will specifically compare the causes of death (including cancer, suicide, heart disease and infection) between people with MS and the general population.

Dr. Kingwell will also investigate cancer survival of MS patients in comparison to the general population, which is an area of some controversy. She will determine how frequently MS is listed as an underlying or contributing cause of death, which will help to facilitate planning and interpretation of population-based studies of MS mortality trends. Findings from this study will further our understanding of the role that MS plays in long-term health outcomes, such as cancer survival, and will broaden our existing knowledge of factors associated with longevity in MS. These results will also provide a vital estimate of the impact of immunomodulatory therapy on survival and specific causes of death for MS. The findings from this research will have a profound impact on the care, monitoring and treatment of the disease.