Figure 1.
A hypothetical death certificate for a deceased patients with multiple sclerosis (MS) based on the standard death certificate format. [8] For this patient, the immediate cause of death (COD) would be cardiopulmonary arrest and the underlying COD would be MS. However, sepsis would be considered the principal COD.
Figure 2.
Algorithm for determining principal cause of death (COD) and primary disease/injury categories.
The algorithm used to determine the principal COD based on ICD-10 codes. These codes were then sorted into 10 major disease/injury categories. aIncludes all ICD-10 codes not assigned to one of the other categories; examples include diabetes mellitus, all gastrointestinal diseases, hematologic diseases, etc.
Table 1.
Distribution of patients with MS and non-MS comparators.
Table 2.
Number of deaths and mortality rate/100,000 person-years (95% confidence interval) by major disease/injury category according to principal, underlying, and immediate cause of death (COD).
Figure 3.
Difference in mortality rate (95% CI) between patients with MS relative to non-MS comparators by underlying, immediate, and principal COD.
The difference in mortality rate between the MS and non-MS comparator cohorts using all 3 methods of determining COD. Positive values indicate disease/injury categories in which the MS cohort had a higher mortality rate. aComparator was a non-MS population matched for age, sex, and residence region. One subject in the comparator group developed MS post-entry into the study. bOther includes suicide, accidental death, cancer, and those with an unknown COD.
Figure 4.
Contribution of subcategories of principal COD to differences in mortality rate (95% CI) between in patients with MS relative to non-MS comparators.
Contribution of subcategories of principal COD to difference in mortality rate. Subcategories were only derived from the following main categories: infection, pulmonary disease, cardiovascular disease, and other. Cancer is shown only as a main category. aOther principal COD subcategories evaluated but for which excess deaths in the MS cohort were <4/100,000 person-years included: accidental falls, asthma, chronic obstructive pulmonary disease, decubitus ulcers, dementia, diabetes, hepatic disease, paralytic disease, and renal disease.