[show abstract][hide abstract] ABSTRACT: We compared race disparities in health services use in a national sample of adults from the 2002 Medical Expenditure Panel Survey and data from the Exploring Health Disparities in Integrated Communities Project, a 2003 survey of adult residents from a low-income integrated urban community in Maryland. In the Medical Expenditure Panel Survey data, African Americans were less likely to have a health care visit compared with Whites. However, in the Exploring Health Disparities in Integrated Communities Project, the integrated community, African Americans were more likely to have a health care visit than Whites. The race disparities in the incidence rate of health care use among persons who had at least one visit were similar in both samples. Our findings suggest that disparities in health care utilization may differ across communities and that residential segregation may be a confounding factor.
Medical Care Research and Review 06/2009; 66(5):578-89. · 3.01 Impact Factor
[show abstract][hide abstract] ABSTRACT: Disparities in hypertension between African Americans and non-Hispanic whites have been well-documented, yet an explanation for this persistent disparity remains elusive. Since African Americans and non-Hispanic white Americans tend to live in very different social environments, it is not known whether race disparities in hypertension would persist if non-Hispanic whites and African Americans were exposed to similar social environments. We compared data from the Exploring Health Disparities in Integrated Communities-SWB (EHDIC-SWB) Study with the National Health and Nutrition Examination Survey (NHANES) 1999-2004 to determine if race disparities in hypertension in the USA were attenuated in EHDIC-SWB, which is based in a racially integrated community without race differences in income. Hypertension was defined as systolic blood pressure (BP)Â >=Â 140Â mmHg (millimeters of mercury) and/or diastolic BPÂ >=Â 90Â mmHg or respondent's report of taking antihypertensive medications. Of the 1408 study participants, 835 (59.3%) were African American, 628 (44.6%) were men, and the mean age was 40.6 years. After adjustment for potential confounders, various analytic models from EHDIC-SWB and NHANES 1999-2004 data, we found the race odds ratio was between 29.0% and 34% smaller in the EHDIC-SWB sample. We conclude that social and environmental exposures explained a substantial proportion of the race difference in hypertension.
Social Science & Medicine. 01/2008; 67(10):1604-1611.
[show abstract][hide abstract] ABSTRACT: To decompose sources of individual differences in coping as measured by John Henryism among African Americans.
Analyses described in this study are based on the pairwise responses from 180 pairs of same-sex, African-American twin pairs who participated in the Carolina African-American Twins Study of Aging (CAATSA). The sample consisted of 85 monozygotic (MZ) and 95 dizygotic (DZ) twin pairs.
Environmental factors account for most of the variance (65%) in John Henryism scores, with the remaining variance attributable to additive genetic factors (35%). The test of the genetic component suggested that the 35% represented a statistically significant proportion of variance.
The vast majority of recent studies on African Americans and health outcomes have focused on the impact of psychosocial factors on diseases such as hypertension and diabetes, with relatively little attention to possible genetic contributors. Previous research on psychosocial indices and their relationship to cardiovascular health among African Americans has focused on assessment and epidemiological explorations rather than understanding the etiology of variability in such measures.
Journal of the National Medical Association 05/2006; 98(4):641-7. · 0.91 Impact Factor
[show abstract][hide abstract] ABSTRACT: To examine race differences in knowledge of the Tuskegee study and the relationship between knowledge of the Tuskegee study and medical system mistrust.
We conducted a telephone survey of 277 African-American and 101 white adults 18-93 years of age in Baltimore, MD. Participants responded to questions regarding mistrust of medical care, including a series of questions regarding the Tuskegee Study of Untreated Syphilis in the Negro Male (Tuskegee study).
Findings show no differences by race in knowledge of or about the Tuskegee study and that knowledge of the study was not a predictor of trust of medical care. However, we find significant race differences in medical care mistrust.
Our results cast doubt on the proposition that the widely documented race difference in mistrust of medical care results from the Tuskegee study. Rather, race differences in mistrust likely stem from broader historical and personal experiences.
Journal of the National Medical Association 08/2005; 97(7):951-6. · 0.91 Impact Factor
[show abstract][hide abstract] ABSTRACT: Previous research found measures of pulmonary functioning to be strong predictors of cognitive functioning and mortality; however, there is considerable individual variability in performance on these measures. In the present analyses, the relative contribution of genetic and environmental influences to variability in average peak expiratory flow rate (APEFR) are examined in a sample of adult African-American twins.
Birth records from North Carolina Register of Deeds offices were used to identify participants for the Carolina African-American Twin Study of Aging (CAATSA). Participants completed an in-person interview, which included measures of health status, cognition, and psychosocial measures.
Data for the analysis come from 200 pairs of same sex twins (97 identical pairs, and 113 fraternal), with a mean age = 46.9 years (SD = 13.9), and with 39% of the sample being men.
Phenotypic correlations between APEFR, age, gender, height, and cigarette consumption (measured in pack years), were all significant, ranging from -.63 to .43. After the affects of age, gender, height, and pack years were partialled out of APEFR, quantitative genetic analyses were conducted on the residuals. Model fitting demonstrated that variance in APEFR was accounted for by shared environmental effects (30%), genetic effects (14%), and non-shared environmental effects (56%).
These results are discussed in relation to previous research conducted in other countries, and the importance of a complex systems approach to explanations of the impact of genes on central indices of health, such as APEFR.
[show abstract][hide abstract] ABSTRACT: The John Henryism (JH) hypothesis argues that prolonged high-effort coping with chronic psychosocial stressors may be associated with elevated risk for negative health outcomes among those without sufficient socioeconomic resources. Early JH studies found a significant association between high JH, low socioeconomic status, and hypertension among African-Americans. More recently, these findings have been extended to a wide array of health status outcomes, including cardiovascular reactivity, neurohormonal secretion, and negative health behaviors. The present review provides a comprehensive overview of JHs conceptual bases and empirical support. Limitations of the construct are discussed and recommendations are made to guide future theoretical and research efforts in the area.
Psychology & Health - PSYCHOL HEALTH. 01/2004; 19(3):369-383.
[show abstract][hide abstract] ABSTRACT: The development and testing of explanatory hypotheses about the underlying mechanisms that create health disparities among ethnic minorities will be crucial in identifying solutions for reducing the current differentials. This paper addresses the potential for using genetic information as a useful and necessary addition to approaches to measures of the "environment" in the study of the origins of health disparities. Approaches and theoretical perspectives on the integration of social science and genetic findings are discussed.
Journal of the National Medical Association 08/2003; 95(7):539-43. · 0.91 Impact Factor
[show abstract][hide abstract] ABSTRACT: The purpose of the present study was to identify sources of variability for systolic blood pressure (SBP), diastolic blood pressure (DBP), and pulse pressure (PP) in a sample of adult African-American twins.
The classic twin design was employed to examine genetic and environmental sources of variance in the outcome measures of interest.
Participants were 143 (71 MZ and 72 DZ) same-sex, intact twin pairs (mean age = 49.87 years; SD 13.62), who took part in the Carolina African-American Twin Study of Aging (CAATSA).
Outcome measures of interest included SBP and DBP, and PP.
For older twins, heritabilities were .52 for SBP, .36 for DBP, and .14 for PP. However, for younger twins, heritabilities were .44 for SBP, .27 for DBP, but no genetic influence on PP was observed.
The results indicate that genetic factors are a significant source of variance in hemodynamic indices, and also suggest that, with advancing age, genetic factors play an increasing role in determining blood pressure and PP in this population.
[show abstract][hide abstract] ABSTRACT: In twin research, typically both members of a pair must participate. Survivorship of members of intact pairs compared to surviving members of nonintact twin pairs may reflect differences in psychosocial and health factors, and represent a potential selection bias relative to the general population. The purpose of the present study is to examine health, cognition, and well-being among members of African American intact twin pairs compared to individuals from nonintact twin pairs. Data from the Carolina African American Twin Study of Aging (CAATSA) were used for analyses. Subjects ranged in age from 25 to 89 years of age (mean = 59.78 years, SD = 12.84 years). CAATSA implements a 3-h protocol to collect data on demographics, health, cognition, and well-being. Data from one randomly selected member of each twin pair (N = 78) was compared to data from surviving members of nonintact twin pairs (N = 52). The results indicated significant differences on 11 of the 39 measures (i.e., age, education, forced expiratory volume, mean standing and sitting systolic and diastolic blood pressures, cognitive impairment score, alpha span, digit symbol, and logical memory). In each case, members of intact twin pairs performed better than surviving members of nonintact twin pairs. After controlling demographic variables, only blood pressures differed between the groups. It appears that using only pairs in research on older African American twins may represent a selection bias in estimating origins of individual variability in cognitive functioning and health but not psychological well-being.
Experimental Aging Research 01/2003; 29(4):407-23. · 1.11 Impact Factor
[show abstract][hide abstract] ABSTRACT: To investigate the genetic and environmental influences on body-fat measures including waist circumference (WC), waist-to-hip ratio (WHR), and body mass index (BMI) among African-American men and women.
Measurements were taken as part of the Carolina African American Twin Study of Aging. This sample currently comprises 146 same-sex African-American twins with an average age of 50 years (range, 22 to 88 years). This analysis included 26 monozygotic and 29 dizygotic men and 45 monozygotic and 46 dizygotic women. Maximum likelihood quantitative genetic analysis was used.
In men, additive genetic effects accounted for 77% of the variance in WC, 59% in WHR, and 89% in BMI. In women, additive genetic effects accounted for 76% of the variance in WC, 56% in WHR, and 73% in BMI. The remaining variance in both men and women was attributed to unique environmental effects (WC, 21%; WHR, 36%; BMI, 11% in men and WC, 22%; WHR, 38%; BMI, 27% in women) and age (WC, 2%; WHR, 5% in men and WC, 2%; WHR, 6% in women). When BMI was controlled in the analysis of WC and WHR, it accounted for a portion of the genetic and environmental variance in WHR and over one-half of the genetic and environmental variance in WC.
There are both genetic and environmental influences on WC, WHR, and BMI, and independent of BMI, there are genetic and environmental effects on WC and WHR among both genders. The results from this African-American twin sample are similar to findings among white twin samples.
Obesity research 09/2002; 10(8):733-9. · 4.95 Impact Factor
[show abstract][hide abstract] ABSTRACT: As the aging population continues to become more diverse, there is growing interest in understanding the similar and unique aspects of aging within and across people of different ethnic groups. The impact of culture on the sources of variation identified in quantitative genetic approaches has not been well discussed in the literature. The purpose of this paper is to review previous research pertinent to the cultural aspects of quantitative genetic approaches and methodologies, and provide conceptual and statistical approaches for advancing the science. To meet this objective, results from previously published studies as well as preliminary data analyses from the Carolina African American Twin Study of Aging will be presented. There are three themes to draw from the issues discussed in this paper: (1) avoiding genetic reductionism, (2) interpreting differential heritabilities, and (3) modeling cultural influences.
Experimental Aging Research 01/2002; 28(4):391-405. · 1.11 Impact Factor
[show abstract][hide abstract] ABSTRACT: Participants: Data for the analysis come from 200 pairs of same sex twins (97 identical pairs, and 113 fraternal), with a mean age546.9 years (SD513.9), and with 39% of the sample being men. Results: Phenotypic correlations between APEFR, age, gender, height, and cigarette con- sumption (measured in pack years), were all significant, ranging from 2.63 to .43. After the affects of age, gender, height, and pack years were partialled out of APEFR, quantitative ge- netic analyses were conducted on the residu- als. Model fitting demonstrated that variance in APEFR was accounted for by shared envi- ronmental effects (30%), genetic effects (14%), and non-shared environmental effects (56%). Conclusion: These results are discussed in re- lation to previous research conducted in other countries, and the importance of a complex systems approach to explanations of the im- pact of genes on central indices of health, such as APEFR. (Ethn Dis. 2004;14:206-211.)