Abstract P351: Sick Population and Sick Subpopulations: Racial Disparities in Coronary Heart Disease Risk in the United States
Introduction: Mortality from coronary heart disease (CHD) has declined substantially in the United States but not all racial groups have benefited equally and it is not clear which population-wide and targeted interventions would further reduce CHD mortality as well as its racial disparities. Previous studies have compared the two approaches separately using different data sources and methods, and a few studies that have used consistent data have ignored the associations between CHD risk factors. We recalibrated and validated a novel risk score to estimate the 10-year risk of fatal CHD in a nationally representative sample of the US population. We estimated the effects of different population-wide and targeted interventions on reducing the risk of CHD and its racial disparities.
Methods: We used data on 6,154 individuals aged 50 to 69 years, who were black or white and free of CHD from 7 rounds of the National Health and Nutrition Examination Survey 1999-2012. The model was developed using data from 8 prospective cohorts in the US and included age, sex, systolic blood pressure, serum cholesterol, diabetes and smoking. We recalibrated the model using age-sex-race specific CHD mortality rates from the Vital Registration system. We estimated the 10-year risk of fatal CHD by sex and race under the current risk factor levels as well as under different population-wide and targeted interventions. The targeted interventions identified individuals with a single elevated risk factor or a high predicted risk based on the risk score model. We also estimated the prevalence of fatal CHD risk ≥2.5% (equivalent to 7.5% risk of fatal or nonfatal CHD risk per AHA guidelines) and ≥ 6.67% (20% risk per ATP-III guidelines) in each subgroup and examined the racial disparities.
Results: Most blacks had a predicted fatal CHD risk similar to whites of the same sex and age, but a small group of blacks were at much higher risk than their white counterparts. Specifically, 18% of black men were at high risk (20% or more risk of CHD in 10 years) compared with only 8% of white men. The same estimates for women were 8% for blacks compared with 2% for whites. Similarly, 61% of black men and 29% of black women were at moderate risk (7.5% or more risk of CHD in 10 years) compared with only 44% in white men and 11% in white women. Population-wide and risk-factor-based interventions were not effective in reducing black-white disparities in CHD risk. Only an intervention that targeted individuals with high CHD risk and treated several risk factors simultaneously could effectively reduce black-white disparities.
Conclusions: Racial disparities in CHD risk are mostly due to existence of a sick sub-population. A risk-based intervention that identifies and treats these individuals could substantially reduce both the overall risk of CHD and its racial disparities in the US. Population-wide and risk-factor-based interventions did not reduce racial disparities.
Author Disclosures: Y. Lu: None. K. Hajifathalian: None. P. Ueda: None. M. Ezzati: None. E. Rimm: None. G. Danaei: None.
- © 2015 by American Heart Association, Inc.