摘要：Objectives. We explored differences between Black and White men for cardiovascular disease (CVD) mortality across major risk factor levels. Methods. Major CVD risk factors were measured among 300 647 White and 20 223 Black men aged 35 to 57 years who were screened for the Multiple Risk Factor Intervention Trial (MRFIT). Hazard ratios for CVD deaths for Black and White men over 25 years of follow-up were calculated for subgroups stratified according to risk factor levels. Results. CVD was responsible for 2518 deaths among Black men and 30772 deaths among White men. The age-adjusted Black-to-White CVD hazard ratio was 1.35 (95% confidence interval [CI]=1.29, 1.40); the risk- and income-adjusted ratio was 1.05 (95% CI=1.01, 1.10). CVD mortality rates were dramatically lower in cases of favorable risk profiles. However, fully adjusted Black-to-White CVD hazard ratios within groups at low, intermediate, high, and very high levels of overall risk were 1.76, 1.20, 1.10, and 0.94, respectively. Similar gradients were evident for individual risk factors. Conclusions. Higher CVD mortality rates among Black men were largely mediated by risk factors and income. These data underscore the need for sustained primordial risk factor prevention among Black men. During the latter half of the 20th century, life expectancies among Black men and women in the United States were consistently lower than those among White men and women. In 2000, the life expectancy for Black men and women was 71.7 vs 77.4 years for White men and women, a difference of 5.7 years (vs 8.3 in 1950). 1 For men, the difference was 6.8 years (vs 7.4 years in 1950). In 2000, age-adjusted US mortality rates from diseases of the circulatory system (codes I00–I99 in the International Statistical Classification of Diseases, 10th Revision 2 [ ICD-10 ]) were 50.7 per 10000 among Black men and 39.6 per 10000 among White men. 3 Continuing to reduce disparities between mortality rates for Black and White men has been a priority of US federal policymakers since 1985, when the Office of Minority Health was created by the Department of Health and Human Services. 4 Eliminating health disparities is one of the 2 overarching goals of the Healthy People 2010 initiative, launched in 2000, 5 , 6 and is a goal of the National Institutes of Health’s strategic research plan for reducing health disparities during fiscal years 2002 through 2006. 7 Central to this goal is an enhanced understanding of the nature and causes of mortality differences between Black men and White men. Between 1973 and 1975, 361662 men (including 317910 White men and 22 792 Black men) aged 35 to 57 years were screened for the Multiple Risk Factor Intervention Trial (MRFIT). Data were collected on cardiovascular disease (CVD) risk factors, race/ethnicity, and zip code of residence. A previous article reported that, after 16 years of follow-up, the age-adjusted Black-to-White hazard ratio for death because of CVD among men screened for the trial was 1.36; further adjustment for estimated household income on the basis of zip code area reduced this ratio to 1.09. 8 Similar reductions after adjusting for income were also evident for non-CVD causes of death. No studies, to our knowledge, have reported differences in CVD mortality rates between Black men and White men according to major risk factor subgroups. Such differences may indicate underlying variations in medical treatment, health behaviors, or genetic characteristics (all of which have been indicated in previous literature) and may also motivate targeted intervention efforts. In our study, we used 25 years of mortality follow-up data from the men screened for MRFIT to compare CVD mortality hazard ratios for Black and White men across several variables: age, blood pressure, serum cholesterol, tobacco use, use of medication for diabetes, previous hospitalization for a myocardial infarction, overall risk, and income. Analyses were conducted with and without adjustment for income to clarify the interplay among race/ethnicity, major risk factors, and income. The null hypotheses tested were that differences in CVD mortality for Black and White men were largely mediated through risk factors and income and that, after adjustment for risk factors and income, they would be constant across risk factor levels.
