Abstract
Objective: We aimed to compare survival in the multiple sclerosis (MS) population with a matched cohort from the general population, and to evaluate the association of comorbidity with survival in both populations.
Methods: Using population-based administrative data, we identified 5,797 persons with MS and 28,807 controls matched on sex, year of birth, and region. We estimated annual mortality rates. Using Cox proportional hazards regression, we evaluated the association between comorbidity status and mortality, stratifying by birth cohort, and adjusting for sex, socioeconomic status, and region. We compared causes of death between populations.
Results: Median survival from birth in the MS population was 75.9 years vs 83.4 years in the matched population. MS was associated with a 2-fold increased risk of death (adjusted hazard ratio 2.40; 95% confidence interval: 2.24–2.58). Several comorbidities were associated with increased hazard of death in both populations, including diabetes, ischemic heart disease, depression, anxiety, and chronic lung disease. The magnitude of the associations of mortality with chronic lung disease, diabetes, hypertension, and ischemic heart disease was lower in the MS population than the matched population. The most common causes of death in the MS population were diseases of the nervous system and diseases of the circulatory system. Mortality rates due to infectious diseases and diseases of the respiratory system were higher in the MS population.
Conclusion: In the MS population, survival remained shorter than expected. Within the MS population, comorbidity was associated with increased mortality risk. However, comorbidity did not preferentially increase mortality risk in the MS population as compared with controls.
GLOSSARY
- CI=
- confidence interval;
- HR=
- hazard ratio;
- ICD-9=
- International Classification of Diseases, Ninth Revision;
- ICD-9-CM=
- International Classification of Diseases, Ninth Revision, Clinical Modification;
- ICD-10-CA=
- International Classification of Diseases, Tenth Revision, Canada;
- IHD=
- ischemic heart disease;
- MS=
- multiple sclerosis;
- RR=
- relative risk
Footnotes
Go to Neurology.org for full disclosures. Funding information and disclosures deemed relevant by the authors, if any, are provided at the end of the article. The Article Processing Charge was paid by an operating grant from the MS Society of Canada.
Supplemental data at Neurology.org
- Received November 7, 2014.
- Accepted in final form March 19, 2015.
- © 2015 American Academy of Neurology
This is an open access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives License 4.0 (CC BY-NC-ND), which permits downloading and sharing the work provided it is properly cited. The work cannot be changed in any way or used commercially.
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