Higher Heart Failure Mortality, Lower Socioeconomic Status Linked in New Study

Differences in heart failure mortality over the previous 2 decades can partially be explained by social determinants of health (SDOH) prevalent in the counties in which patients live, particularly the level of socioeconomic deprivation, notes a recent research letter published in Journal of Cardiac Failure.

It is important that this is understood and known, the authors add, because medication regimens for heart failure typically are expensive, so higher poverty levels could equate to lack of access to health care.

"Analysis of trends in heart failure mortality shows that these disparities have persisted throughout the last two decades," Graham Bevan, MD, a resident physician at University Hospitals in Cleveland, Ohio, and the study’s first author, said in a statement.

Using the 2015 Area Deprivation Index (ADI) and the 2015 Social Deprivation Index (SDI)—both ranging from 0 to 100, so that the higher the total, the worse the socioeconomic deprivation—the authors analyzed the following data:

• County-level mortality data from the US National Center for Health Statistics, age-adjusting the rates by deaths per 100,000 individuals
• International Classification of Diseases, Tenth Edition diagnoses for death from heart failure that used code 150
• Urbanization from the 2013 National Center for Health Statistics urban-rural classification
• Heart failure mortality change in 2 periods: 1999 to 2002 and 2015 to 2018

Of the 1,254,991 heart failure–related deaths from 3048 counties, most (58.2%; 729,990) were among women and in rural counties (22.9%; 287,258). By race, the highest totals were seen among African Americans (9.5%) and Hispanics (3.3%). There were an average 25.5 heart failure deaths/100,000 across all counties, with the median ADI being 61.6 (first quartile, 49.2; third quartile, 71.5) and the median SDI, 43.0 (22.0 and 64.0, respectively).

Analyses revealed that age-adjusted mortality increased across all quartiles of the ADI and SDI and for several indicators of level of socioeconomic deprivation:

• ADI: quartile 1, 20.0 (95% CI, 19.4-20.5); quartile 2, 23.3 (95% CI, 22.6-24.0); quartile 3, 26.4 (95% CI, 25.5-27.3); quartile 4: 33.1 (95% CI, 31.8-34.4)
• SDI: quartile 1, 22.1 (95% CI, 21.4-22.7); quartile 2, 23.8 (95% CI, 23.1-24.4); quartile 3, 27.1 (95% CI, 25.9-28.2); quartile 4, 30.2 (95% CI, 29.0-31.4)
• Nonmetropolitan areas: ADI quartiles 1-4: 20.5, 23.3, 26.3, 32.9; SDI quartiles 1-4: 22.4, 25.1, 29.0, 32.8
• Metropolitan areas: ADI quartiles 1-4: 19.7, 23.3, 26.8, 35.1; SDI quartiles 1-4: 21.7, 22.0, 23.9, 32.8
• Caucasian: ADI quartiles 1-4: 20.1, 23.5, 26.7, 33.3; SDI quartiles 1-4: 22.3, 24.1, 27.4, 25.6
• African American: ADI quartiles 1-4: 22.0, 28.6, 34.1, 43.7; SDI quartiles 1-4: 23.7, 26.1, 32.0, 34.6
• Male: ADI quartiles 1-4: 22.0, 26.1, 30.1, 38.2; SDI quartiles 1-4: 25.2, 26.1, 29.9, 33.6
• Female: ADI quartiles 1-4: 18.8, 21.9, 25.2, 31.9; SDI quartiles 1-4: 21.2, 22.4, 25.7, 28.0

Overall, even when accounting for race/ethnicity, sex, and urbanization level, higher socioeconomic deprivation in a county still pointed to higher totals of heart failure mortality. Proposed reasons for this persistent relationship include low health literacy, poor social support, and substandard care, noted the authors.

“Regardless of the contributing factors, the association between communities with high socioeconomic deprivation and [heart failure] mortality is strong, and it suggests that targeting social deprivation may be impactful in reducing [heart failure] mortality,” they concluded. “Additionally, the yield of intensive [heart failure] preventive strategies may be higher in areas with high social deprivation.”

Limitations to generalizing these study results are 2-fold: the use of death certificate data and converting ADI data from a census tract level to a county level.

Reference

Bevan GH, Josephson R, Al-Kindi SG. Socioeconomic deprivation and heart failure mortality in the United States. J Card Fail. Published online August 2, 2020. doi:10.1016/j.cardfail.2020.07.014