Heart Disease Death Rates Among Blacks and Whites Aged ≥35 Years - United States, 1968-2015

Abstract

Problem/condition: Heart disease is the leading cause of death in the United States. In 2015, heart disease accounted for approximately 630,000 deaths, representing one in four deaths in the United States. Although heart disease death rates decreased 68% for the total population from 1968 to 2015, marked disparities in decreases exist by race and state.

Period covered: 1968-2015.

Description of system: The National Vital Statistics System (NVSS) data on deaths in the United States were abstracted for heart disease using diagnosis codes from the eighth, ninth, and tenth revisions of the International Classification of Diseases (ICD-8, ICD-9, and ICD-10) for 1968-2015. Population estimates were obtained from NVSS files. National and state-specific heart disease death rates for the total population and by race for adults aged ≥35 years were calculated for 1968-2015. National and state-specific black-white heart disease mortality ratios also were calculated. Death rates were age standardized to the 2000 U.S. standard population. Joinpoint regression was used to perform time trend analyses.

Results: From 1968 to 2015, heart disease death rates decreased for the total U.S. population among adults aged ≥35 years, from 1,034.5 to 327.2 per 100,000 population, respectively, with variations in the magnitude of decreases by race and state. Rates decreased for the total population an average of 2.4% per year, with greater average decreases among whites (2.4% per year) than blacks (2.2% per year). At the national level, heart disease death rates for blacks and whites were similar at the start of the study period (1968) but began to diverge in the late 1970s, when rates for blacks plateaued while rates for whites continued to decrease. Heart disease death rates among blacks remained higher than among whites for the remainder of the study period. Nationwide, the black-white ratio of heart disease death rates increased from 1.04 in 1968 to 1.21 in 2015, with large increases occurring during the 1970s and 1980s followed by small but steady increases until approximately 2005. Since 2005, modest decreases have occurred in the black-white ratio of heart disease death rates at the national level. The majority of states had increases in black-white mortality ratios from 1968 to 2015. The number of states with black-white mortality ratios >1 increased from 16 (40%) to 27 (67.5%).

Interpretation: Although heart disease death rates decreased both for blacks and whites from 1968 to 2015, substantial differences in decreases were found by race and state. At the national level and in most states, blacks experienced smaller decreases in heart disease death rates than whites for the majority of the period. Overall, the black-white disparity in heart disease death rates increased from 1968 to 2005, with a modest decrease from 2005 to 2015.

Public health action: Since 1968, substantial increases have occurred in black-white disparities of heart disease death rates in the United States at the national level and in many states. These increases appear to be due to faster decreases in heart disease death rates for whites than blacks, particularly from the late 1970s until the mid-2000s. Despite modest decreases in black-white disparities at the national level since 2005, in 2015, heart disease death rates were 21% higher among blacks than among whites. This study demonstrates the use of NVSS data to conduct surveillance of heart disease death rates by race and of black-white disparities in heart disease death rates. Continued surveillance of temporal trends in heart disease death rates by race can provide valuable information to policy makers and public health practitioners working to reduce heart disease death rates both for blacks and whites and disparities between blacks and whites.

FIGURE 1

Heart disease death rates* and annual percentage changes among adults aged ≥35 years, by race — United States, 1968–2015 * Per 100,000 population, age standardized to the 2000 U.S. standard population. ^† Vertical lines indicate the year that the slope changed according to joinpoint trend analysis. ^§ All annual percentage changes were significant (p<0.05), except -1.0 during 2010–2015 for whites and -0.6 during 2011–2015 for the total population.

FIGURE 2

Black-white heart disease mortality ratios and annual percentage changes among adults aged ≥35 years — United States, 1968–2015 * Vertical lines indicate the year that the slope changed according to joinpoint trend analysis. ^† All annual percentage changes were significant (p<0.05), except 0.

FIGURE 3

Heart disease death rates* among black and white adults aged ≥35 years — United States, 1968 and 2015 Abbreviation: Q = quartile. * Per 100,000 population, age standardized to the 2000 U.S. standard population. State-level heart disease death rates were not calculated when <20 deaths occurred in the state within a group (blacks or whites) because the rates are considered statistically unreliable. For each year, quartiles are based on the distribution of rates for blacks and whites combined. The use of consistent quartile cutpoints within each year allows for the comparison of the distribution of high and low rates for blacks vs. whites within 1968 and 2015, respectively.

FIGURE 4

Black-white heart disease mortality ratios* among adults aged ≥35 years — United States, 1968 and 2015 * State-level heart disease death rates were not calculated when <20 deaths occurred in the state within a group (blacks or whites) because the rates are considered statistically unreliable. Ratio categories are based on statistical testing using 95% confidence intervals (CIs). Black-white mortality rate ratios with CIs that include 1 represent approximately equal rates of heart disease deaths among blacks and whites. Ratios with upper CIs <1 indicate lower heart disease death rates among blacks compared with whites, and ratios with lower CIs >1 indicate higher heart disease death rates among blacks compared with whites.