Underlying cause of death in Danish patients with multiple sclerosis: results from the Danish Multiple Sclerosis Registry
- aThe Danish Multiple Sclerosis Registry, Rigshospitalet 7013, Tagensvej 20, DK-2200 Copenhagen N, Denmark, bDepartment of Neurology, Aalborg Hospital North, DK-9100 Aalborg, Denmark, cThe Danish Institute for Clinical Epidemiology, Svanemøllevej 25, DK-2100 Copenhagen Ø, Denmark, dDepartment of Neurology, Esbjerg Hospital, DK-6700 Esbjerg, Denmark
- Correspondance to: Dr Nils Koch-Henriksen, Department of Neurology, Aalborg Hospital North, DK-9100 Aalborg, Denmark. Fax: 0045 99 32 19 58; email: niko{at}post3.tele.dk
- Received 20 October 1997
- Revised 5 January 1998
- Accepted 13 January 1998
Abstract
OBJECTIVES To determine the underlying causes of death in a large population based register series of patients with multiple sclerosis.
METHODS The Danish Multiple Sclerosis Registry, which contains virtually all diagnosed cases of multiple sclerosis in Denmark who were alive in 1949 plus cases with onset of multiple sclerosis in the period 1949–93, who have been diagnosed and notified by 1 January 1994, was linked with the Danish Registry of Causes of Death, in which ICD codes for causes of death from the death certificate are stored for all Danish citizens.
RESULTS 6068 register cases of multiple sclerosis, who had died in the period 1951–93, were included. Multiple sclerosis was noted on the death certificate as the underlying cause of death in 55.4%; cardiac or vascular diseases in 17.6%; cancers in 8.6%; respiratory or infectious diseases in 5.1%; other natural causes in 9.5%; accident or suicide in 3.8%. The distribution varied with age at death. Standardised mortality ratios (SMRs) were computed on the basis of the 8142 incident cases, who had onset of multiple sclerosis within the period 1951–93; the SMRs for causes of death other than multiple sclerosis were highest for infectious or pulmonary diseases: 2.46 (95% confidence interval (95% CI) 2.04–2.94); suicide: 1.62 (95% CI 1.29–2.01); cardiac or vascular diseases: 1.34 (95% CI 1.22–1.48); accidents 1.34 (95% CI 1.02–1.71); and significantly lower than unity for cancers: 0.79 (95% CI 0.70–0.90), lower for men than for women.
CONCLUSIONS More than half of the patients with multiple sclerosis die from multiple sclerosis or complications of the disease. Among other causes, patients with multiple sclerosis have an increased risk of dying from heart or vascular diseases but a reduced risk of dying from cancer. An increased risk of death from suicide and accidents can be indirectly attributed to multiple sclerosis. The diminished risk of dying from cancer may be a result of incomplete ascertainment of cancers in disabled patients with multiple sclerosis.
- multiple sclerosis complications
- multiple sclerosis mortality
- cause of death
- death certificates
- registries statistics and numerical data
