Redistribution of heart failure as the cause of death: the Atherosclerosis Risk in Communities Study

Abstract

Background: Heart failure is sometimes incorrectly listed as the underlying cause of death (UCD) on death certificates, thus compromising the accuracy and comparability of mortality statistics. Statistical redistribution of the UCD has been used to examine the effect of misclassification of the UCD attributed to heart failure, but sex- and race-specific redistribution of deaths on coronary heart disease (CHD) mortality in the United States has not been examined.

Methods: We used coarsened exact matching to infer the UCD of vital records with heart failure as the UCD from 1999 to 2010 for decedents 55 years old and older from states encompassing regions under surveillance by the Atherosclerosis Risk in Communities (ARIC) Study (Maryland, Minnesota, Mississippi, and North Carolina). Records with heart failure as the UCD were matched on decedent characteristics (five-year age groups, sex, race, education, year of death, and state) to records with heart failure listed among the multiple causes of death. Each heart failure death was then redistributed to plausible UCDs proportional to the frequency among matched records.

Results: After redistribution the proportion of deaths increased for CHD, chronic obstructive pulmonary disease, diabetes, hypertensive heart disease, and cardiomyopathy, P < 0.001. The percent increase in CHD mortality after redistribution was the highest in Mississippi (12%) and lowest in Maryland (1.6%), with variations by year, race, and sex. Redistribution proportions for CHD were similar to CHD death classification by a panel of expert reviewers in the ARIC study.

Conclusions: Redistribution of ill-defined UCD would improve the accuracy and comparability of mortality statistics used to allocate public health resources and monitor mortality trends.

Figure 1

Flow diagram of exclusions.

Figure 2

Percent increase in age-adjusted mortality rate for coronary heart disease after redistribution of heart failure deaths by state. Age-adjusted mortality rate is per 100,000 population among US adults ≥55 years, age-standardized to the 2000 US standard population. MD, Maryland; MN, Minnesota; MS, Mississippi; NC, North Carolina.

Figure 3

Percent increase in age-adjusted mortality rate for coronary heart disease after redistribution of heart failure deaths by sex and state. Age-adjusted mortality rate is per 100,000 population among US (a) male and (b) female adults ≥55 years, age-standardized to the 2000 US standard population. MD, Maryland; MN, Minnesota; MS, Mississippi; NC, North Carolina.

Figure 4

Percent increase in age-adjusted mortality rate for coronary heart disease after redistribution of heart failure deaths by race and state. Age-adjusted mortality rate is per 100,000 population among US (a) Caucasian and (b) African American adults ≥55 years, age-standardized to the 2000 US standard population. Data for African Americans in Minnesota were suppressed because of small numbers. MD, Maryland; MN, Minnesota; MS, Mississippi; NC, North Carolina.