According to the results of an observational analysis published in the Annals of Internal Medicine, heart disease appears more prevalent in low-income counties compared with high-income counties across the United States. Investigators also found that, in low-income counties, mortality related to heart disease and cancer does not appear to be decreasing in a similar pattern to that observed in high-income counties.
Records obtained from the National Center for Health Statistics Multiple Cause of Death mortality files between 2003 and 2015 were used to identify decedents age 25 years or older in all 50 US states. The main measurements of interest included the incidence of all-cause mortality, heart disease mortality, and cancer mortality. Analyses of the primary measures were stratified by county median household income. Data from a total of 32,510,810 people from 3143 US counties were included.
In 2003 and 2015, the leading cause of death in 79% and 59% of counties, respectively, was heart disease. Mortality attributed to cancer was reported in 21% and 41% of counties in 2003 and 2015, respectively. Highest-income counties experienced the greatest shift in cancer-related mortality between 2003 and 2015. Mortality rates for heart disease decreased by approximately 28% between 2003 and 2015, according to the adjusted analysis.
The decrease in heart disease-related mortality was greater in high-income counties vs low-income counties (30% vs 22%, respectively). The reduction in cancer-related mortality was also greater in high- vs low-income counties between 2003 and 2015 (18% vs 11%, respectively). Heart disease remained the leading cause of mortality in low-income counties between 2003 and 2015 among all racial and ethnic groups.
Limitations of the analysis include its retrospective and observational nature as well as the reliance on county median household income as a determining factor for socioeconomic status.
“Failure to account for differences in mortality by socioeconomic status and race/ethnicity in national reports may further marginalize populations already at increased risk for certain diseases or death,” the researchers concluded. “Our findings may help inform improved policies, research, and clinical agendas as the United States moves through the epidemiologic transition in chronic disease-related mortality — from heart disease to cancer — in the coming decades.”
Hastings KG, Boothroyd DB, Kapphahn K, et al. Socioeconomic differences in the epidemiologic transition from heart disease to cancer as the leading cause of death in the United States, 2003 to 2015: an observational study [published online November 13, 2018]. Ann Intern Med. doi: 10.7326/M17-0796