Does Segregation Lead to Lower Birth Weight?: An Instrumental Variable Approach

School Segregation During Adolescence is Associated with Higher 30-Year Cardiovascular Risk of Black but not White Young Adults

Although cardiovascular disease (CVD) mortality rates are declining for American adults, a disparity remains between non-Hispanic Black and non-Hispanic White adults. Previous research has shown that residential segregation, a form of structural racism, experienced in childhood is associated with later-life racial and ethnic health disparities, including disparities in CVD and its risk factors. However, little is known about the health consequences of exposure to segregated schools, especially among those living in neighborhoods with high concentrations of minoritized people. This study used data from the In-School, Wave I, and Wave IV surveys of the National Longitudinal Study of Adolescent to Adult Health to examine a novel school measure of school racial segregation (Index of the Concentration of Extremes, ICE) as a predictor of Framingham 30-year CVD risk scores. We used General Estimating Equation models to evaluate the association between ICE, measured at Wave I, and two different 30-year CVD risk scores, measured at Wave IV, and examined whether the relationship varied by race. We observed that higher levels of school segregation were associated with a higher 30-year CVD risk among non-Hispanic Black participants while higher segregation was associated with a lower 30-year CVD risk for non-Hispanic White participants. This research suggests that exposure to segregation in the school setting may contribute to observed disparities in CVD among US adults.

Born on the wrong side of the tracks: Exploring the causal effects of segregation on infant health

Prior research has found that a high level of residential racial segregation, or the degree to which racial/ethnic groups are isolated from one another, is associated with worsened infant health outcomes, particularly among non-Hispanic (NH) Black infant populations. However, because exposure to segregation is non-random, it is unclear whether and to what extent segregation is causally linked to infant health. To overcome this empirical limitation, we leverage exogenous variation in the placement of railroad tracks in the 19th century to predict contemporary segregation, an approach first introduced by Ananat (2011). In alignment with prior literature, we find that residential segregation has statistically significant associations with negative birth outcomes among Black infant populations in the area. Using OLS methods underestimates the negative impacts of segregation on infant health. We fail to detect comparable effects on health outcomes among NH White infant populations. Further, we identify several key mechanisms by which residential segregation could influence health outcomes among Black infant populations, including lower access to prenatal care during the first trimester, higher levels of anti-Black prejudice, greater transportation barriers, and increased food insecurity. Given that poor birth outcomes have adverse effects on adults' health and well-being, the findings suggest that in-utero exposure to residential segregation could have important implications for Black-White inequality over the life course.

Measuring the Effect of Neighborhood Racial Segregation on Fetal Growth

Prior studies of neighborhood racial segregation and intrauterine growth have not accounted for confounding factors in early life. We used the Life-Course Influences on Fetal Environment Study of births to Black women in metropolitan Detroit, 2009-2011, (N = 1,408) to examine whether health and social conditions in childhood and adulthood confound or modify the association of neighborhood segregation (addresses during pregnancy geocoded to census tract racial composition) and gestational age-adjusted birthweight. Before adjusting for covariates, women living in a predominantly (≥75%) Black neighborhood gave birth to 47.3 grams (95% CI: -99.0, 4.4) lighter infants, on average, compared with women living in <75% Black neighborhoods. This association was confounded by adulthood (age at delivery, parity, neighborhood deprivation) and childhood (parental education, neighborhood racial composition) factors and modified by adulthood socioeconomic position. These findings underscore the complex relationship between neighborhood racial segregation and birth outcomes, which would be enhanced through a life course framework.

Whither weathering? The variable significance of age in Black-White low birth weight disparities

This paper uses birth certificate data to provide novel estimates of the age-specific risk of a low birth weight birth (LBW, an infant born weighting <2500 g) for U.S.-born non-Hispanic Black and White mothers, and finds that patterns vary markedly over space and time. Notably, risk of an LBW birth for Black mothers increased much more steeply with age in 1991-94 than in 2014-17. This decline in LBW risks among older Black mothers led to a decline in the Black-White LBW gap of more than half a percentage point. Both patterns and changes were regional; while age gradients on the Black-White LBW gap were lowest in the South in 1991-94, by 2014-17 they had increased in the South and declined in the rest of the country. These descriptive data allow a new examination of hypotheses regarding the causes of age-specific racial LBW gaps. Research has found that racial disparities in a number of health outcomes, including LBW, increase with age, leading some to speculate that this increase is due to the cumulative effects of exposure to disadvantage. The large degree of variability in Black-White LBW disparities suggests that age-specific causes may also play a role. A series of counterfactual trend analyses explore the roles of two specific mechanisms, smoking and hypertension, and compares these to a more fundamental indicator of socioeconomic status: education.

Unequal care: Racial/ethnic disparities in neonatal intensive care delivery

Advances in neonatal intensive care have improved outcomes for preterm newborns, but significant racial/ethnic disparities persist. Neonatal disparities have their origin in a complex set of factors that include systemic racism and structural disadvantages endured by minority families, but differential quality of care in the neonatal intensive care unit (NICU) remains an important and modifiable source of disparity. NICU care has been shown to be segregated and unequal: Black and Hispanic infants are more likely to be cared for in lower quality NICUs and may receive worse care within a NICU. To eliminate disparities in care and outcomes, it is important to identify and address the mechanisms that lead to lower quality care for minority preterm infants. In this review, we identify improvements in both technical (clinical) and relational (engaging and supporting families) processes of care as critical to better outcomes for minority infants and families.

Multilevel social factors and NICU quality of care in California

OBJECTIVE

Our objective was to incorporate social and built environment factors into a compendium of multilevel factors among a cohort of very low birth weight infants to understand their contributions to inequities in NICU quality of care and support providers and NICUs in addressing these inequities via development of a health equity dashboard.

STUDY DESIGN

We examined bivariate associations between NICU patient pool and NICU catchment area characteristics and NICU quality of care with data from a cohort of 15,901 infants from 119 NICUs in California, born 2008-2011.

RESULT

NICUs with higher proportion of minority racial/ethnic patients and lower SES patients had lower quality scores. NICUs with catchment areas of lower SES, higher composition of minority residents, and more household crowding had lower quality scores.

CONCLUSION

Multilevel social factors impact quality of care in the NICU. Their incorporation into a health equity dashboard can inform providers of their patients' potential resource needs.

Assessing differential impacts of COVID-19 on black communities

Purpose

Given incomplete data reporting by race, we used data on COVID-19 cases and deaths in U.S. counties to describe racial disparities in COVID-19 disease and death and associated determinants.

Methods

Using publicly available data (accessed April 13, 2020), predictors of COVID-19 cases and deaths were compared between disproportionately (≥13%) black and all other (<13% black) counties. Rate ratios were calculated, and population attributable fractions were estimated using COVID-19 cases and deaths via zero-inflated negative binomial regression model. National maps with county-level data and an interactive scatterplot of COVID-19 cases were generated.

Results

Nearly 90% of disproportionately black counties (656/677) reported a case and 49% (330/677) reported a death versus 81% (1987/2465) and 28% (684/2465), respectively, for all other counties. Counties with higher proportions of black people have higher prevalence of comorbidities and greater air pollution. Counties with higher proportions of black residents had more COVID-19 diagnoses (Rate Ratio (RR): 1.24, 95% confidence interval: 1.17-1.33) and deaths (RR: 1.18, 95% confidence interval: 1.00-1.40), after adjusting for county-level characteristics such as age, poverty, comorbidities, and epidemic duration. COVID-19 deaths were higher in disproportionally black rural and small metro counties. The population attributable fraction of COVID-19 diagnosis due to lack of health insurance was 3.3% for counties with less than 13% black residents and 4.2% for counties with greater than or equal to 13% black residents.

Conclusions

Nearly 20% of U.S. counties are disproportionately black, and they accounted for 52% of COVID-19 diagnoses and 58% of COVID-19 deaths nationally. County-level comparisons can both inform COVID-19 responses and identify epidemic hot spots. Social conditions, structural racism, and other factors elevate risk for COVID-19 diagnoses and deaths in black communities.

Racial and ethnic disparities in adverse birth outcomes: Differences by racial residential segregation

Racial and ethnic disparities in adverse birth outcomes have persistently been wide and may be explained by individual and area-level factors. Our primary objective was to determine if county-level black-white segregation modified the association between maternal race/ethnicity and adverse birth outcomes using birth records from the National Center for Health Statistics (2012). Based on maternal residence at birth, county-level black-white racial residential segregation was calculated along five dimensions of segregation: evenness, exposure, concentration, centralization, and clustering. We conducted a two-stage analysis: (1) county-specific logistic regression to determine whether maternal race and ethnicity were associated with preterm birth and term low birth weight; and (2) Bayesian meta-analyses to determine if segregation moderated these associations. We found greater black-white and Hispanic-white disparities in preterm birth in racially isolated counties (exposure) relative to non-isolated counties. We found reduced Hispanic-white disparities in term low birth weight in racially concentrated and centralized counties relative to non-segregated counties. Area-level poverty explained most of the moderating effect of segregation on disparities in adverse birth outcomes, suggesting that area-level poverty is a mediator of these associations. Segregation appears to modify racial/ethnic disparities in adverse birth outcomes. Therefore, policy interventions that reduce black-white racial isolation, or buffer the poor social and economic correlates of segregation, may help to reduce disparities in preterm birth and term low birth weight.

Use of real-world evidence from healthcare utilization data to evaluate drug safety during pregnancy

PURPOSE

Because preapproval clinical trials typically exclude pregnant women, the evidence on drug safety during pregnancy required to inform drug labeling must come from postapproval controlled observational studies. Common designs have included pregnancy registries and case-control studies. Recently, pregnancy cohorts nested within healthcare utilization databases are increasingly being used. Despite clear advantages, these databases share some important limitations that may threaten the validity of studies emerging from them.

METHODS

This paper describes the distinctive methodological aspects of conducting drug safety studies in healthcare utilization databases with special emphasis on design and analytic approaches to minimize biases.

RESULTS

We describe considerations for study design, cohort definition, and follow-up. We then address issues related to exposure ascertainment based on prescription fills, including the importance of the etiologically relevant window and of properly accounting for preterm births. This is followed by a discussion of advantages and challenges when ascertaining maternal and infant outcomes based on secondary data. We then explore useful approaches to address confounding within the context of pregnancy research and of the potential for selection bias when restricting the cohort to live births. Finally, we consider issues related to external validity and statistical significance. The examples are mainly drawn from a pregnancy cohort nested in the Medicaid Analytic Extract.

CONCLUSIONS

The approaches presented provide guidance regarding the important methodological considerations that need to be attended to in order to generate valid, minimally biased risk when using large healthcare utilization databases for drug safety surveillance in pregnancy.

Racial residential segregation and racial disparities in stillbirth in the United States

We examined whether current and/or persistent racial residential segregation is associated with black-white stillbirth disparities among 49,969 black and 71,785 white births from the Consortium on Safe Labor (2002-2008). Black-white segregation was measured using the dissimilarity index and the isolation index, categorized into population-based tertiles. Using hierarchical logistic models, we found low and decreasing levels of segregation were associated with decreased odds of stillbirth, with blacks benefitting more than whites. Decreasing segregation may prevent approximately 900 stillbirths annually among U.S. blacks. Reducing structural racism, segregation in particular, could help reduce black-white stillbirth disparities.

Racial residential segregation and adverse birth outcomes: A systematic review and meta-analysis

RATIONALE

Persistent racial disparities in adverse birth outcomes are not fully explained by individual-level risk factors. Racial residential segregation-degree to which two or more groups live apart from one another-may contribute to the etiology of these birth outcome disparities. Our aim was to assess associations between segregation and adverse birth outcomes by race. This review focused on formal measures of segregation, using Massey and Denton's framework (1998) that identifies five distinct operationalizations of segregation, in addition to proxy measures of segregation such as racial composition, in order to gain a deeper understanding of the operationalizations of segregation most salient for birth outcomes.

METHOD

Review and meta-analyses were conducted using PubMed, PsycINFO and Web of Science and included articles from inception through April 30, 2017.

RESULTS

Forty-two articles examined associations between segregation and adverse birth outcomes among Black and White mothers separately. Meta-analyses showed that among Black mothers, exposure was associated with increased risk of preterm birth (OR = 1.17, 95% CI = 1.10, 1.26), and low birth weight (OR = 1.13, 95% CI=1.06, 1.21), and Black racial composition was associated with increased risk of preterm birth (OR = 1.20, 95% CI=1.05, 1.37), among those living in most- compared to least-segregated neighborhoods. Few studies were conducted among White mothers and only exposure was associated with increased risk of preterm birth and low birth weight. Qualitative analyses indicated that among Black mothers, exposure and hypersegregation were associated with multiple adverse birth outcomes; findings were mixed for evenness and clustering.

CONCLUSIONS AND FUTURE DIRECTIONS

Associations between segregation and adverse birth outcomes differ by race. Methodological heterogeneity between studies may obscure true associations. Research can be advanced through use of multilevel frameworks and by examining mechanistic pathways between segregation and adverse birth outcomes. Elucidation of pathways may provide opportunities to intervene to reduce seemingly intractable racial disparities in adverse birth outcomes.

Black-white metropolitan segregation and self-rated health: Investigating the role of neighborhood poverty

While black-white segregation has been consistently linked to detrimental health outcomes for blacks, whether segregation is necessarily a zero-sum arrangement in which some groups accrue health advantages at the expense of other groups and whether metropolitan segregation impacts the health of racial groups uniformly within the metropolitan area, remains unclear. Using nationally representative data from the 2008-2013 National Health Interview Survey linked to Census data, we investigate whether the association between metropolitan segregation and health is invariant within the metropolitan area or whether it is modified by neighborhood poverty for black and white Americans. In doing so, we assess the extent to which segregation involves direct health tradeoffs between blacks and whites. We conduct race-stratified multinomial and logistic regression models to assess the relationship between 1) segregation and level of neighborhood poverty and 2) segregation, neighborhood poverty, and poor health, respectively. We find that, for blacks, segregation was associated with a higher likelihood of residing in high poverty neighborhoods, net of individual-level socioeconomic characteristics. Segregation was positively associated with poor health for blacks in high poverty neighborhoods, but not for those in lower poverty neighborhoods. Hence, the self-rated health of blacks clearly suffers as a result of black-white segregation - both directly, and indirectly through exposure to high poverty neighborhoods. We do not find consistent evidence for a direct relationship between segregation and poor health for whites. However, we find some suggestive evidence that segregation may indirectly benefit whites through decreasing their exposure to high poverty environments. These findings underscore the critical role of concentrated disadvantage in the complex interconnection between metropolitan segregation and health. Weakening the link between racial segregation and concentrated poverty via local policy and planning has the potential for broad population-based health improvements and significant reductions in black-white health disparities.