A Bayesian Approach to Modeling Variance of Intensive Longitudinal Biomarker Data as a Predictor of Health Outcomes

Intensive longitudinal biomarker data are increasingly common in scientific studies that seek temporally granular understanding of the role of behavioral and physiological factors in relation to outcomes of interest. Intensive longitudinal biomarker data, such as those obtained from wearable devices, are often obtained at a high frequency typically resulting in several hundred to thousand observations per individual measured over minutes, hours, or days. Often in longitudinal studies, the primary focus is on relating the means of biomarker trajectories to an outcome, and the variances are treated as nuisance parameters, although they may also be informative for the outcomes. In this paper, we propose a Bayesian hierarchical model to jointly model a cross-sectional outcome and the intensive longitudinal biomarkers. To model the variability of biomarkers and deal with the high intensity of data, we develop subject-level cubic B-splines and allow the sharing of information across individuals for both the residual variability and the random effects variability. Then different levels of variability are extracted and incorporated into an outcome submodel for inferential and predictive purposes. We demonstrate the utility of the proposed model via an application involving bio-monitoring of hertz-level heart rate information from a study on social stress

Interpersonal discrimination and depressive symptomatology: examination of several personality-related characteristics as potential confounders in a racial/ethnic heterogeneous adult sample

Abstract Background Research suggests that reports of interpersonal discrimination result in poor mental health. Because personality characteristics may either confound or mediate the link between these reports and mental health, there is a need to disentangle its role in order to better understand the nature of discrimination-mental health association. We examined whether hostility, anger repression and expression, pessimism, optimism, and self-esteem served as confounders in the association between perceived interpersonal discrimination and CESD-based depressive symptoms in a race/ethnic heterogeneous probability-based sample of community-dwelling adults. Methods We employed a series of ordinary least squares regression analyses to examine the potential confounding effect of hostility, anger repression and expression, pessimism, optimism, and self-esteem between interpersonal discrimination and depressive symptoms. Results Hostility, anger repression, pessimism and self-esteem were significant as possible confounders of the relationship between interpersonal discrimination and depressive symptoms, together accounting for approximately 38% of the total association (beta: 0.1892, p < 0.001). However, interpersonal discrimination remained a positive predictor of depressive symptoms (beta: 0.1176, p < 0.001). Conclusion As one of the first empirical attempts to examine the potential confounding role of personality characteristics in the association between reports of interpersonal discrimination and mental health, our results suggest that personality-related characteristics may serve as potential confounders. Nevertheless, our results also suggest that, net of these characteristics, reports of interpersonal discrimination are associated with poor mental health.http://deepblue.lib.umich.edu/bitstream/2027.42/112604/1/12889_2013_Article_6001.pd

Interpersonal discrimination and depressive symptomatology: examination of several personality-related characteristics as potential confounders in a racial/ethnic heterogeneous adult sample

Background Research suggests that reports of interpersonal discrimination result in poor mental health. Because personality characteristics may either confound or mediate the link between these reports and mental health, there is a need to disentangle its role in order to better understand the nature of discrimination-mental health association. We examined whether hostility, anger repression and expression, pessimism, optimism, and self-esteem served as confounders in the association between perceived interpersonal discrimination and CESD-based depressive symptoms in a race/ethnic heterogeneous probability-based sample of community-dwelling adults. Methods We employed a series of ordinary least squares regression analyses to examine the potential confounding effect of hostility, anger repression and expression, pessimism, optimism, and self-esteem between interpersonal discrimination and depressive symptoms. Results Hostility, anger repression, pessimism and self-esteem were significant as possible confounders of the relationship between interpersonal discrimination and depressive symptoms, together accounting for approximately 38% of the total association (beta: 0.1892, p \u3c 0.001). However, interpersonal discrimination remained a positive predictor of depressive symptoms (beta: 0.1176, p \u3c 0.001). Conclusion As one of the first empirical attempts to examine the potential confounding role of personality characteristics in the association between reports of interpersonal discrimination and mental health, our results suggest that personality-related characteristics may serve as potential confounders. Nevertheless, our results also suggest that, net of these characteristics, reports of interpersonal discrimination are associated with poor mental health

Racial and Ethnic Differences in the Association Between Obesity and Depression in Women

Background: It is generally accepted that obesity and depression are positively related in women. Very little prior research, however, has examined potential variation in this relationship across different racial/ethnic groups. This paper examines the association between obesity and depression in non-Hispanic White, non-Hispanic Black, and Mexican American women. Methods: The sample included women aged 20 years and older in the 2005?2008 National Health and Nutrition Examination Surveys (n=3666). Logistic regression was used to assess the relationship between obesity and depression syndrome (assessed using the Patient Health Questionnaire-9), after adjusting for covariates. We then investigated whether this association varied by race/ethnicity. Results: Overall, obese women showed a 73% greater odds of depression (odds ratio [OR]=1.73; 95% confidence interval [CI]=1.19, 2.53) compared with normal weight women. This association varied significantly, however, by race/ethnicity. The obesity-depression associations for both Black and Mexican American women were different from the positive association found for White women (ORBlack*obese=0.24; 95% CI=0.10,0.54; ORMexican American*obese=0.42; 95% CI=1.04). Among White women, obesity was associated with significantly greater likelihood of depression (OR=2.37; 95% CI=1.41, 4.00) compared to normal weight. Among Black women, although not statistically significant, results are suggestive that obesity was inversely associated with depression (OR=0.56; 95% CI=0.28, 1.12) relative to normal weight. Among Mexican American women, obesity was not associated with depression (OR=1.01; 95% CI=0.59, 1.72). Conclusions: The results reveal that the association between obesity and depression varies by racial/ethnic categorization. White, but not Black or Mexican American women showed a positive association. Next research steps could include examination of factors that vary by race/ethnicity that may link obesity to depression.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140124/1/jwh.2012.4111.pd

Original Contribution Do Psychosocial Stress and Social Disadvantage Modify the Association Between Air Pollution and Blood Pressure? The Multi-Ethnic Study of Atherosclerosis

Researchers have theorized that social and psychosocial factors increase vulnerability to the deleterious health effects of environmental hazards. We used baseline examination data (2000)(2001)(2002) from the Multi-Ethnic Study of Atherosclerosis. Participants were 45-84 years of age and free of clinical cardiovascular disease at enrollment (n = 6814). The modifying role of social and psychosocial factors on the association between exposure to air pollution comprising particulate matter less than 2.5 µm in aerodynamic diameter (PM 2.5 ) and blood pressure measures were examined using linear regression models. There was no evidence of synergistic effects of higher PM 2.5 and adverse social/psychosocial factors on blood pressure. In contrast, there was weak evidence of stronger associations of PM 2.5 with blood pressure in higher socioeconomic status groups. For example, those in the 10th percentile of the income distribution (i.e., low income) showed no association between PM 2.5 and diastolic blood pressure (b = −0.41 mmHg; 95% confidence interval: −1.40, 0.61), whereas those in the 90th percentile of the income distribution (i.e., high income) showed a 1.52-mmHg increase in diastolic blood pressure for each 10-µg/m 3 increase in PM 2.5 (95% confidence interval: 0.22, 2.83). Our results are not consistent with the hypothesis that there are stronger associations between PM 2.5 exposures and blood pressure in persons of lower socioeconomic status or those with greater psychosocial adversity. air pollution; blood pressure; population groups; social environment; social medicine; social psychology Abbreviations: CVD, cardiovascular disease; DBP, diastolic blood pressure; ETS, exposure to second-hand smoke; MAP, mean arterial pressure; MESA, Multi-Ethnic Study of Atherosclerosis; PM 2.5 , particulate matter less than 2.5 µm in aerodynamic diameter; PP, pulse pressure; SBP, systolic blood pressure; SES, socioeconomic status

Association of Changes in Neighborhood-Level Racial Residential Segregation With Changes in Blood Pressure Among Black Adults: The CARDIA Study

Importance: Despite cross-sectional evidence linking racial residential segregation to hypertension prevalence among non-Hispanic blacks, it remains unclear how changes in exposure to neighborhood segregation may be associated with changes in blood pressure. Objective: To examine the association of changes in neighborhood-level racial residential segregation with changes in systolic and diastolic blood pressure over a 25-year period. Design, Setting, and Participants: This observational study examined longitudinal data of 2280 black participants of the Coronary Artery Risk Development in Young Adults (CARDIA) study, a prospective investigation of adults aged 18 to 30 years who underwent baseline examinations in field centers in 4 US locations from March 25, 1985, to June 7, 1986, and then were re-examined for the next 25 years. Racial residential segregation was assessed using the Getis-Ord Gi* statistic, a measure of SD between the neighborhood\u27s racial composition (ie, percentage of black residents) and the surrounding area\u27s racial composition. Segregation was categorized as high (Gi* \u3e 1.96), medium (Gi* 0-1.96), and low (Gi* \u3c 0). Fixed-effects linear regression modeling was used to estimate the associations of within-person change in exposure to segregation and within-person change in blood pressure while tightly controlling for time-invariant confounders. Data analyses were performed between August 4, 2016, and February 9, 2017. Main Outcomes and Measures: Within-person changes in systolic and diastolic blood pressure across 6 examinations over 25 years. Results: Of the 2280 participants at baseline, 974 (42.7%) were men and 1306 (57.3%) were women. Of these, 1861 (81.6%) were living in a high-segregation neighborhood; 278 (12.2%), a medium-segregation neighborhood; and 141 (6.2%), a low-segregation neighborhood. Systolic blood pressure increased by a mean of 0.16 (95% CI, 0.06-0.26) mm Hg with each 1-SD increase in segregation score after adjusting for interactions of time with age, sex, and field center. Of the 1861 participants (81.6%) who lived in high-segregation neighborhoods at baseline, reductions in exposure to segregation were associated with reductions in systolic blood pressure. Mean differences in systolic blood pressure were -1.33 (95% CI, -2.26 to -0.40) mm Hg when comparing high-segregation with medium-segregation neighborhoods and -1.19 (95% CI, -2.08 to -0.31) mm Hg when comparing high-segregation with low-segregation neighborhoods after adjustment for time and interactions of time with baseline age, sex, and field center. Changes in segregation were not associated with changes in diastolic blood pressure. Conclusions and Relevance: Decreases in exposure to racial residential segregation are associated with reductions in systolic blood pressure. This study adds to the small but growing body of evidence that policies that reduce segregation may have meaningful health benefits

Racism as a determinant of health: a systematic review and meta-analysis

Despite a growing body of epidemiological evidence in recent years documenting the health impacts of racism, the cumulative evidence base has yet to be synthesized in a comprehensive meta-analysis focused specifically on racism as a determinant of health. This meta-analysis reviewed the literature focusing on the relationship between reported racism and mental and physical health outcomes. Data from 293 studies reported in 333 articles published between 1983 and 2013, and conducted predominately in the U.S., were analysed using random effects models and mean weighted effect sizes. Racism was associated with poorer mental health (negative mental health: r = -.23, 95% CI [-.24,-.21], k = 227; positive mental health: r = -.13, 95% CI [-.16,-.10], k = 113), including depression, anxiety, psychological stress and various other outcomes. Racism was also associated with poorer general health (r = -.13 (95% CI [-.18,-.09], k = 30), and poorer physical health (r = -.09, 95% CI [-.12,-.06], k = 50). Moderation effects were found for some outcomes with regard to study and exposure characteristics. Effect sizes of racism on mental health were stronger in cross-sectional compared with longitudinal data and in non-representative samples compared with representative samples. Age, sex, birthplace and education level did not moderate the effects of racism on health. Ethnicity significantly moderated the effect of racism on negative mental health and physical health: the association between racism and negative mental health was significantly stronger for Asian American and Latino(a) American participants compared with African American participants, and the association between racism and physical health was significantly stronger for Latino(a) American participants compared with African American participants.<br /

Interaction of Social Factors and Environmental Pollutants in Black-White Health Disparities: The Case of Lead and Hypertension.

The black-white disparities in hypertension have been well-documented for decades. Disparities in the social and physical environments are thought to be fundamental determinants of the disparities in hypertension. In addition to their independent effects, the social and physical environments may interact to result in hypertension. Social stress, in particular, has been shown to amplify the harmful effects of environmental pollutants. To date, no one has examined the notion that social stress and environmental pollutants interact to produce and maintain black-white hypertension disparities. To test this interaction, I focus on the documented finding from previous studies that there is a positive association between blood lead and blood pressure in black but not white adults. In this dissertation, I hypothesize that black-white disparities in social stress amplify the harmful effects of lead to result in an effect of blood lead on blood pressure for black but not white adults. Using data from the National Health and Nutrition Examination Survey (NHANES) 2001-2006, I examine the role of depressive symptoms, as a proxy of psychosocial stress, and educational attainment and poverty status, as proxies of socioeconomic constraints and resources, in the lead-blood pressure association. Black women who report high levels of depressive symptoms show a 7.2mmHg increase in systolic blood pressure for each doubling of blood lead (p<0.05) while black women who report low levels of depressive symptoms show a 1.2mmHg increase (p=NS). Black men show a similar pattern. Black men without a high school education experience a 4.9mmHg increase (p<0.001) in systolic blood pressure for each doubling of blood lead, while black men with at least a high school education experience a 2.0mmHg increase (p<0.05). Black women do not show this pattern. Both poor and nonpoor black men and women show similar increases in systolic blood pressure due to lead. Overall, these results suggest that social factors can amplify the harmful effects of lead.Ph.D.Health Behavior & Health EducationUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/77758/1/mhicken_1.pd

Measurement and modeling of race and health in Brazil: continuing the discussion

Recent reviews have discussed the conceptualization of race in health studies in Brazil. This review further documents and discusses specific measurement and modeling issues with regard to race and how this can impact result interpretation. Three scientific databases were used to search the literature on race and three health outcomes. The search yielded 38 empirical studies on birth outcomes, self-rated health, and weight. Results suggest that, while there are racial patterns in the overall literature, conceptual and methodological challenges can be addressed to clarify the ways in which racial group membership is linked to health