Decomposing Black-White Disparities in Heart Disease Mortality in the United States, 1973-2010: An Age-Period-Cohort Analysis.

Against the backdrop of late 20th century declines in heart disease mortality in the United States, race-specific rates diverged because of slower declines among blacks compared with whites. To characterize the temporal dynamics of emerging black-white racial disparities in heart disease mortality, we decomposed race-sex-specific trends in an age-period-cohort (APC) analysis of US mortality data for all diseases of the heart among adults aged ≥35 years from 1973 to 2010. The black-white gap was largest among adults aged 35-59 years (rate ratios ranged from 1.2 to 2.7 for men and from 2.3 to 4.0 for women) and widened with successive birth cohorts, particularly for men. APC model estimates suggested strong independent trends across generations ("cohort effects") but only modest period changes. Among men, cohort-specific black-white racial differences emerged in the 1920-1960 birth cohorts. The apparent strength of the cohort trends raises questions about life-course inequalities in the social and health environments experienced by blacks and whites which could have affected their biomedical and behavioral risk factors for heart disease. The APC results suggest that the genesis of racial disparities is neither static nor restricted to a single time scale such as age or period, and they support the importance of equity in life-course exposures for reducing racial disparities in heart disease.

Metropolitan racial residential segregation and cardiovascular mortality: exploring pathways.

Racial residential segregation has been associated with an increased risk for heart disease and stroke deaths. However, there has been little research into the role that candidate mediating pathways may play in the relationship between segregation and heart disease or stroke deaths. In this study, we examined the relationship between metropolitan statistical area (MSA)-level segregation and heart disease and stroke mortality rates, by age and race, and also estimated the effects of various educational, economic, social, and health-care indicators (which we refer to as pathways) on this relationship. We used Poisson mixed models to assess the relationship between the isolation index in 265 U.S. MSAs and county-level (heart disease, stroke) mortality rates. All models were stratified by race (non-Hispanic black, non-Hispanic white), age group (35-64 years, ≥ 65 years), and cause of death (heart disease, stroke). We included each potential pathway in the model separately to evaluate its effect on the segregation-mortality association. Among blacks, segregation was positively associated with heart disease mortality rates in both age groups but only with stroke mortality rates in the older age group. Among whites, segregation was marginally associated with heart disease mortality rates in the younger age group and was positively associated with heart disease mortality rates in the older age group. Three of the potential pathways we explored attenuated relationships between segregation and mortality rates among both blacks and whites: percentage of female-headed households, percentage of residents living in poverty, and median household income. Because the percentage of female-headed households can be seen as a proxy for the extent of social disorganization, our finding that it has the greatest attenuating effect on the relationship between racial segregation and heart disease and stroke mortality rates suggests that social disorganization may play a strong role in the elevated rates of heart disease and stroke found in racially segregated metropolitan areas.

Spatial clustering of non-transported cardiac decedents: the results of a point pattern analysis and an inquiry into social environmental correlates.

BACKGROUND: People who die from heart disease at home before any attempt at transport has been made may represent missed opportunities for life-saving medical intervention. In this study, we undertook a point-pattern spatial analysis of heart disease deaths occurring before transport in a large metropolitan area to determine whether there was spatial clustering of non-transported decedents and whether there were significant differences between the clusters of non-transported cardiac decedents and the clusters of transported cardiac decedents in terms of average travel distances to nearest hospital and area socioeconomic characteristics. These analyses were adjusted for individual predictors of transport status. METHODS: We obtained transport status from the place of death variable on the death certificate. We geocoded heart disease decedents to residential street addresses using a rigorous, multistep process with 97% success. Our final study population consisted of 11,485 adults aged 25-74 years who resided in a large metropolitan area in west-central Florida and died from heart disease during 1998-2002. We conducted a kernel density analysis to identify clusters of the residential locations of cardiac decedents where there was a statistically significant excess probability of being either transported or not transported prior to death; we controlled for individual-level covariates using logistic regression-derived probability estimates. RESULTS: The majority of heart disease decedents were married (53.4%), male (66.4%), white (85.6%), and aged 65-74 years at the time of death (54.7%), and a slight majority were transported prior to death (57.7%). After adjustment for individual predictors, 21 geographic clusters of non-transported heart disease decedents were observed. Contrary to our hypothesis, clusters of non-transported decedents were slightly closer to hospitals than clusters of transported decedents. The social environmental characteristics of clusters varied in the expected direction, with lower socioeconomic and household resources in the clusters of non-transported heart disease deaths. CONCLUSIONS: These results suggest that in this large metropolitan area unfavorable household and neighborhood resources played a larger role than distance to hospital with regard to transport status of cardiac patients; more research is needed in different geographic areas of the United States and in other industrialized nations.

A multilevel analysis of absence of transport to a hospital before premature cardiac death.

INTRODUCTION: Prompt transportation to a hospital and aggressive medical treatment can often prevent acute cardiac events from becoming fatal. Consequently, lack of transport before death may represent lost opportunities for life-saving interventions. We investigated the effect of individual characteristics (age, sex, race/ethnicity, education, and marital status) and small-area factors (population density and social cohesion) on the probability of premature cardiac decedents dying without transport to a hospital. METHODS: We analyzed death data for adults aged 25 to 69 years who resided in the Tampa, Florida, metropolitan statistical area and died from an acute cardiac event from 1998 through 2002 (N = 2,570). Geocoding of decedent addresses allowed the use of multilevel (hierarchical) logistic regression models for analysis. RESULTS: The strongest predictor of dying without transport was being unmarried (odds ratio, 2.13; 95% confidence interval, 1.79-2.52, P < .001). There was no effect of education; however, white race was modestly predictive of dying without transport. Younger decedent age was a strong predictor. Multilevel statistical modeling revealed that less than 1% of the variance in our data was found at the small-area level. CONCLUSION: Results contradicted our hypothesis that small-area characteristics would increase the probability of cardiac patients receiving transport before death. Instead we found that being unmarried, a proxy of living alone and perhaps low social support, was the most important predictor of people who died from a cardiac event dying without transport to a hospital.

Small-area racial disparity in stroke mortality: an application of bayesian spatial hierarchical modeling.

BACKGROUND: In the United States, excess burden of stroke mortality has persisted among African Americans compared with whites despite declines in stroke mortality for both groups. New insights may be gleaned by examining local, small-area patterns in racial disparities in stroke. METHODS: The study population includes all non-Hispanic African Americans and non-Hispanic whites aged 35 to 64 in the southeastern United States during 1999 to 2002. We assessed county-level numbers of stroke deaths and population estimates in a Bayesian spatial hierarchical modeling framework allowing for inclusion of potential covariates (poverty and rurality), and generating county-specific model-based estimates of both absolute and relative racial disparity. The resulting estimates of race-specific stroke death rates, relative racial disparity, and absolute racial disparity were expressed in maps. RESULTS: After adjustment for age, poverty, and rurality, county-level estimates of relative racial disparity ranged from 2.3 to 3.3 and estimates of absolute racial disparity ranged from 19 to 45 excess deaths per 100,000. For both racial groups, stroke death rates were higher in rural areas and with increasing poverty. High relative racial disparity was concentrated primarily in the eastern portion of the region and large absolute racial disparity was concentrated primarily in the western portion. CONCLUSIONS: The results highlight the pervasiveness and magnitude of substantial local racial disparities in stroke mortality in the southeast.

Social and demographic predictors of no transport prior to premature cardiac death: United States 1999-2000.

BACKGROUND: In the United States, over one-third of premature cardiac deaths occur outside of a hospital, without any transport prior to death. Transport prior to death is a strong, valid indicator of help-seeking behavior. We used national vital statistics data to examine social and demographic predictors of risk of no transport prior to cardiac death. We hypothesized that persons of lower social class, immigrants, non-metropolitan residents, racial/ethnic minorities, men, and younger decedents would be more likely to die prior to transport. METHODS: Our study population consisted of adult residents of the United States, aged 25 to 64 years, who died from heart disease during 1999-2000 (n = 242,406). We obtained transport status from the place of death variable on the death certificate. The independent effects of social and demographic predictor variables on the risk of a cardiac victim dying prior to transport vs. the risk of dying during or after transport to hospital were modeled using logistic regression. RESULTS: Results contradicted most of our a priori hypotheses. Persons of lower social class, immigrants, most non-metropolitan residents, and racial/ethnic minorities were all at lower risk of dying prior to transport. The greatest protective effect was found for racial/ethnic minority decedents compared with whites. The strongest adverse effect was found for marital status: the risk of dying with no transport was more than twice as high for those who were single (OR 2.35; 95% CI 2.29-2.40) or divorced (OR 2.29; 95% CI 2.24-2.34), compared with married decedents. Geographically, residents of the Western United States were at a 47% increased risk of dying prior to transport compared with residents of the metropolitan South. CONCLUSION: Our results suggest that marital status, a broad marker of household structure, social networks, and social support, is more important than social class or race/ethnicity as a predictor of access to emergency medical services for persons who suffer an acute cardiac event. Future research should focus on ascertaining "event histories" for all acute cardiac events that occur in a community, with the goal of identifying the residents most susceptible to cardiac fatalities prior to medical intervention and transport.

Trends in self-reported multiple cardiovascular disease risk factors among adults in the United States, 1991-1999.

BACKGROUND: There are few national- and state-level data on multiple cardiovascular disease (CVD) risk factor status and trends over time. We examined the prevalence of self-reported multiple CVD risk factors from 1991 through 1999. METHODS: The Behavioral Risk Factor Surveillance System is a state-based telephone survey of adults 18 years or older. Surveys in 1991, 1993, 1995, 1997, and 1999 ascertained reported high blood pressure, high blood cholesterol level, diabetes, obesity, and current smoking status. Trends in the prevalence of persons with each risk factor and of having 2 or more risk factors were calculated. Data were age standardized to the 2000 US population. RESULTS: From 1991 to 1999, the prevalence of reported high blood pressure increased from 23.8% to 25.4%, high cholesterol levels increased from 24.9% to 27.7%, diabetes increased from 5.5% to 7.1%, obesity increased from 13.5% to 20.3%, and smoking remained at approximately 21%. The prevalence of adults with 2 or more risk factors increased from 23.6% in 1991 to 27.9% in 1999 and significantly increased for both men and women and for all race or ethnic, age, and education groups. Among states, the prevalence of multiple risk factors ranged from 15.0% to 29.9% in 1991 and from 18.7% to 37.1% in 1999. From 1991 to 1999, the prevalence of multiple risk factors increased by 10% or more in 36 states. CONCLUSIONS: The substantial proportion of persons with known multiple risk factors (25% of the population) suggests that increased CVD prevention and risk factor reduction efforts should focus on comprehensive risk reduction strategies.

Correlates of hypertension among Chippewa and Menominee Indians, the Inter-Tribal Heart Project.

OBJECTIVE: The objective of this study was to document the prevalence and control of hypertension among Chippewa and Menominee Indians who participated in the Inter-Tribal Heart Project (ITHP), and to identify the covariates of controlled hypertension in this population. DESIGN: Participants responded to an interviewer-administered questionnaire and underwent a physical examination and laboratory screening. SETTING/PARTICIPANTS: A random sample of 1376 individuals aged > or = 25 years who were active users of the Indian Health Service clinics on the Chippewa and Menominee Reservations and participated in the ITHP. RESULTS: The prevalence of hypertension (systolic blood pressure [SBP] > or = 140 mm Hg and/ or diastolic blood pressure [DBP] > or = 90 mm Hg and/or currently taking anti-hypertension medications) was 31%. Approximately 25% of individuals with hypertension were unaware of their hypertensive status. Among hypertensives, 58% reported currently using anti-hypertension medications, and only 28% had blood pressures below the recommended levels (SBP < 140 mm Hg or DBP < 90 mm Hg). CONCLUSIONS: The high prevalence of hypertension coupled with the low prevalence of controlled hypertension suggests the need to enhance and strengthen programs that target hypertension prevention and control. These programs should include pharmacologic and non-pharmacologic approaches, as well as culturally appropriate programs that incorporate beliefs held by American Indians about hypertension causation, manifestations and treatment, in an attempt to reduce this group's burden of hypertension.

Transfer of residents to hospital prior to cardiac death: the influence of nursing home quality and ownership type.

OBJECTIVES: We hypothesised that among nursing home decedents, nursing home for-profit status and poor quality-of-care ratings, as well as patient characteristics, would lower the likelihood of transfer to hospital prior to heart disease death. METHODS: Using death certificates from a large metropolitan area (Tampa Florida Metropolitan Statistical Area) for 1998-2002, we geocoded residential street addresses of heart disease decedents to identify 2172 persons who resided in nursing homes (n=131) at the time of death. We analysed decedent place of death as an indicator of transfer prior to death. Multilevel logistic regression modelling was used for analysis. Cause of death and decedent characteristics were obtained from death certificates. Nursing home characteristics, including state inspector ratings for multiple time points, were obtained from Florida's Agency for Healthcare Administration. RESULTS: Nursing home for-profit status, level of nursing care and quality-of-care ratings were not associated with the likelihood of transfer to hospital prior to heart disease death. Nursing homes >5 miles from a hospital were more likely to transfer decedents, compared with facilities located close to a hospital. Significant predictors of no transfer for nursing home residents were being white, female, older, less educated and widowed/unmarried. CONCLUSIONS: In this study population, contrary to our hypotheses, sociodemographic characteristics of nursing home decedents were more important predictors of no transfer prior to cardiac death than quality rankings or for-profit status of nursing homes.

Association of the insulin resistance syndrome and microalbuminuria among nondiabetic native Americans. The Inter-Tribal Heart Project.

This study investigated the association between microalbuminuria and the insulin resistance syndrome (IRS) among nondiabetic Native Americans. In a cross-sectional survey, age-stratified random samples were drawn from the Indian Health Service clinic lists for one Menominee and two Chippewa reservations. Information was collected from physical examinations, personal interviews, and blood and urine samples. The urinary albumin:creatinine ratio (ACR) was measured using a random spot urine sample. The IRS was defined by the number of composite traits: hypertension, impaired fasting glucose (IFG), high fasting insulin, low HDL cholesterol, and hypertriglyceridemia. Among the 934 eligible nondiabetic participants, 15.2% exhibited microalbuminuria. The prevalence of one, two, and three or more traits was 27.0, 16.6, and 7.4%, respectively. After controlling for age, sex, smoking, body mass index, education, and family histories of diabetes and kidney disease, the odds ratio (OR) for microalbuminuria was 1.8 (95% confidence interval [CI], 1.1 to 2.8) for one IRS trait, 1.8 (95% CI, 1.0 to 3.2) for two traits, and 2.3 (95% CI, 1.1 to 4.9) for three or more traits (versus no traits). The pattern of association appeared weaker among women compared with men. Of the individual IRS traits, only hypertension and IFG were associated with microalbuminuria. Among these nondiabetic Native Americans, the IRS was associated with a twofold increased prevalence of microalbuminuria. Health promotion efforts should focus on lowering the prevalence of hypertension, as well as glucose intolerance and obesity, in this population at high risk for renal and cardiovascular disease.