Regional and racial/ethnic inequalities in public drinking water fluoride concentrations across the US.

BACKGROUND: Although the US Centers for Disease Control and Prevention (CDC) considers fluoridation of community water systems (CWSs) to be a major public health achievement responsible for reducing dental disease, recent epidemiologic evidence suggests that chronic exposure to population-relevant levels of fluoride may also be associated with adverse child neurodevelopmental outcomes. To our knowledge, a nationally representative database of CWS fluoride concentration estimates that can be readily linked to US epidemiologic cohorts for further study is not publicly available. Our objectives were to evaluate broad regional and sociodemographic inequalities in CWS fluoride concentrations across the US, and to determine if county-level racial/ethnic composition was associated with county-level CWS fluoride. METHODS: We generated CWS-level (N = 32,495) and population weighted county-level (N = 2152) fluoride concentration estimates using over 250,000 routine compliance monitoring records collected from the US Environmental Protection Agency's (EPA) Third Six Year Review (2006-2011). We compared CWS-level fluoride distributions across subgroups including region, population size served, and county sociodemographic characteristics. In county-level spatial error models, we also evaluated geometric mean ratios (GMRs) of CWS fluoride per 10% higher proportion of residents belonging to a given racial/ethnic subgroup. RESULTS: 4.5% of CWSs (serving >2.9 million residents) reported mean 2006-2011 fluoride concentrations ≥1500 µg/L (the World Health Organization's guideline for drinking water quality). Arithmetic mean, 90th, and 95th percentile contaminant concentrations were greatest in CWSs reliant on groundwater, located in the Southwest and Eastern Midwest, and serving Semi-Urban, Hispanic communities. In fully adjusted spatial error models, the GMR (95% CI) of CWS fluoride per a 10% higher proportion of county residents that were Hispanic/Latino was 1.16 (1.10, 1.23). IMPACT STATEMENT: We find that over 2.9 million US residents are served by public water systems with average fluoride concentrations exceeding the World Health Organization's guidance limit. We also find significant inequalities in community water system fluoride concentration estimates (2006-2011) across the US, especially for Hispanic/Latino communities who also experience elevated arsenic and uranium in regulated public drinking water systems. Our fluoride estimates can be leveraged in future epidemiologic studies to assess the potential association between chronic fluoride exposure and related adverse outcomes.

Disparities in chemical exposures among pregnant women and neonates by socioeconomic and demographic characteristics: A nontargeted approach.

BACKGROUND: Exposure to environmental chemicals during pregnancy adversely affects maternal and infant health, and identifying socio-demographic differences in exposures can inform contributions to health inequities. METHODS: We recruited 294 demographically diverse pregnant participants in San Francisco from the Mission Bay/Moffit Long (MB/ML) hospitals, which serve a primarily higher income population, and Zuckerberg San Francisco General Hospital (ZSFGH), which serves a lower income population. We collected maternal and cord sera, which we screened for 2420 unique formulas and their isomers using high-resolution mass spectrometry using LC-QTOF/MS. We assessed differences in chemical abundances across socioeconomic and demographic groups using linear regression adjusting for false discovery rate. RESULTS: Our participants were racially diverse (31% Latinx, 16% Asian/Pacific Islander, 5% Black, 5% other or multi-race, and 43% white). A substantial portion experienced financial strain (28%) and food insecurity (20%) during pregnancy. We observed significant abundance differences in maternal (9 chemicals) and cord sera (39 chemicals) between participants who delivered at the MB/ML hospitals versus ZSFGH. Of the 39 chemical features differentially detected in cord blood, 18 were present in pesticides, one per- or poly-fluoroalkyl substance (PFAS), 21 in plasticizers, 24 in cosmetics, and 17 in pharmaceuticals; 4 chemical features had unknown sources. A chemical feature annotated as 2,4-dichlorophenol had higher abundances among Latinx compared to white participants, those delivering at ZSFGH compared to MB/ML, those with food insecurity, and those with financial strain. Post-hoc QTOF analyses indicated the chemical feature was either 2,4-dichlorophenol or 2,5-dichlorophenol, both of which have potential endocrine-disrupting effects. CONCLUSIONS: Chemical exposures differed between delivery hospitals, likely due to underlying social conditions faced by populations served. Differential exposures to 2,4-dichlorophenol or 2,5-dichlorophenol may contribute to disparities in adverse outcomes.

Environmental hazards, social inequality, and fetal loss: Implications of live-birth bias for estimation of disparities in birth outcomes.

Restricting to live births can induce bias in studies of pregnancy and developmental outcomes, but whether this live-birth bias results in underestimating disparities is unknown. Bias may arise from collider stratification due to an unmeasured common cause of fetal loss and the outcome of interest, or depletion of susceptibles, where exposure differentially causes fetal loss among those with underlying susceptibility. METHODS: We conducted a simulation study to examine the magnitude of live-birth bias in a population parameterized to resemble one year of conceptions in California (N = 625,000). We simulated exposure to a non-time-varying environmental hazard, risk of spontaneous abortion, and time to live birth using 1000 Monte Carlo simulations. Our outcome of interest was preterm birth. We included a social vulnerability factor to represent social disadvantage, and estimated overall risk differences for exposure and preterm birth using linear probability models and stratified by the social vulnerability factor. We calculated how often confidence intervals included the true point estimate (CI coverage probabilities) to illustrate whether effect estimates differed qualitatively from the truth. RESULTS: Depletion of susceptibles resulted in a larger magnitude of bias compared with collider stratification, with larger bias among the socially vulnerable group. Coverage probabilities were not adversely affected by bias due to collider stratification. Depletion of susceptibles reduced coverage, especially among the socially vulnerable (coverage among socially vulnerable = 46%, coverage among nonsocially vulnerable = 91% in the most extreme scenario). CONCLUSIONS: In simulations, hazardous environmental exposures induced live-birth bias and the bias was larger for socially vulnerable women.

The Relative Economy and Drug Overdose Deaths.

BACKGROUND: Overdose deaths increased exponentially in the United States to be the leading cause of adult injury deaths, and declining economic opportunity may contribute. To our knowledge, there has been no quantitative research into the impact of relative economic measures on overdose risk. Prior longitudinal studies on impact of socioeconomic conditions used fixed effects approaches that can result in biased estimates in the presence of time-varying confounders. METHODS: We estimated county-level longitudinal associations between drug overdose deaths and unemployment and labor-force nonparticipation rates by gender and racial/ethnic subgroup using longitudinal g-computation and the clustered bootstrap. RESULTS: We find evidence for associations between both overall and relative aspects of unemployment and labor-force nonparticipation and drug overdose mortality; patterns of associations differed, sometime qualitatively, across subgroups. For males across racial-ethnic groups, greater overall and relative unemployment rates were generally associated with greater overdose mortality in both the short and long terms [e.g., for white males, increasing the overall percentage of unemployed adults by 5% points in 2000, 2009, and 2015 is associated with an increase of 3.2 overdose deaths (95% confidence interval [CI] = -2.8, 14) in 2015, and increasing the ratio by 0.5 in 2000, 2009, and 2015 is associated with an increase of 9.1 overdose deaths (95% CI = 1.6, 24)]. CONCLUSIONS: These findings point to important complexity in how the economic and contextual landscape differentially shapes overdose risks, underscoring a need for increased understanding of the mechanisms operating for women and minority groups.

Village community mobilization is associated with reduced HIV incidence in young South African women participating in the HPTN 068 study cohort.

INTRODUCTION: Adolescent girls and young women (AGYW) in South Africa bear a disproportionate burden of HIV. Community mobilization (CM), defined as community members taking collective action to achieve a common goal related to health, equity and rights, has been associated with increased HIV testing and condom use and has been called a 'critical enabler' for addressing the HIV epidemic. However, limited research has examined whether CM is associated with HIV incidence among AGYW. METHODS: We examine the association of CM with incident HIV among AGYW (ages 13 to 21) enrolled in the HPTN 068 cohort in the Agincourt Health and socio-Demographic Surveillance System, South Africa. This analysis includes 2292 participants residing in 26 villages where cross-sectional, population-based surveys were conducted to measure CM among 18- to 35-year-old residents in 2012 and 2014. HPTN 068 participants completed up to five annual visits that included an HIV test (2011 to 2016). Household-level data were collected from AGYW parents/guardians and census data is updated annually. Mean village-level CM scores were created using a validated community mobilization measure with seven components (social cohesion, social control, critical consciousness, shared concerns, organizations and networks, leadership and collective action). We used pooled generalized estimating equation regression with a Poisson distribution to estimate risk ratios (RR) for the association of village-level CM score and CM components with incident HIV infection, accounting for village-level clustering and adjusting for key covariates. RESULTS: There were 194 incident infections over the follow-up period. For every additional standard deviation of village-level CM there was 12% lower HIV incidence (RR: 0.88, 95% CI: 0.79, 0.98) after adjusting for individual, household and community characteristics. CM components associated with lower HIV incidence included critical consciousness (RR: 0.88; CI: 0.79, 0.97) and leadership (RR: 0.87; CI: 0.79, 0.95); while not statistically significant, social cohesion (RR: 0.91; CI: 0.81, 1.01), shared concerns (RR: 0.90; CI: 0.81, 1.00), and organizations and networks (RR: 0.91; CI: 0.79, 1.03) may also play a protective role. CONCLUSIONS: These results suggest that having strong community social resources will reduce AGYW's risk of HIV acquisition. Work to mobilize communities, focusing on building social cohesion, shared concerns, critical consciousness, and effective and accountable leadership, can fortify prevention programming for AGYW.

Medicaid Expansions from 1997 to 2009 Increased Coverage and Improved Access and Mental Health Outcomes for Low-Income Parents.

OBJECTIVE: To assess the effects of past Medicaid eligibility expansions to parents on coverage, access to care, out-of-pocket (OOP) spending, and mental health outcomes, and consider implications for the Affordable Care Act (ACA) Medicaid expansion. DATA SOURCES: Person-level data from the National Health Interview Survey (1998-2010) is used to measure insurance coverage and related outcomes for low-income parents. Using state identifiers available at the National Center for Health Statistics Research Data Center, we attach state Medicaid eligibility thresholds for parents collected from a variety of sources to NHIS observations. STUDY DESIGN: We use changes in the Medicaid eligibility threshold for parents within states over time to identify the effects of changes in eligibility on low-income parents. PRINCIPAL FINDINGS: We find that expanding Medicaid eligibility increases insurance coverage, reduces unmet needs due to cost and OOP spending, and improves mental health status among low-income parents. Moreover, our findings suggest that uninsured populations in states not currently participating in the ACA Medicaid expansion would experience even larger improvements in coverage and related outcomes than those in participating states if they chose to expand eligibility. CONCLUSIONS: The ACA Medicaid expansion has the potential to improve a wide variety of coverage, access, financial, and health outcomes for uninsured parents in states that choose to expand coverage.

The health reform monitoring survey: addressing data gaps to provide timely insights into the affordable care act.

The Health Reform Monitoring Survey (HRMS) was launched in 2013 as a mechanism to obtain timely information on the Affordable Care Act (ACA) during the period before federal government survey data for 2013 and 2014 will be available. Based on a nationally representative, probability-based Internet panel, the HRMS provides quarterly data for approximately 7,400 nonelderly adults and 2,400 children on insurance coverage, access to health care, and health care affordability, along with special topics of relevance to current policy and program issues in each quarter. For example, HRMS data from summer 2013 show that more than 60 percent of those targeted by the health insurance exchanges struggle with understanding key health insurance concepts. This raises concerns about some people's ability to evaluate trade-offs when choosing health insurance plans. Assisting people as they attempt to enroll in health coverage will require targeted education efforts and staff to support those with low health insurance literacy.

A decade of health care access declines for adults holds implications for changes in the Affordable Care Act.

The pending Supreme Court decision on the Affordable Care Act and the fall presidential election raise concerns about what would happen if the insurance expansion promised by the landmark health reform law were to be curtailed. This paper's analysis of national survey estimates found that access to health care and use of health services for adults ages 19-64--the primary targets of the Affordable Care Act--deteriorated between 2000 and 2010, particularly among those who were uninsured. More than half of uninsured US adults did not see a doctor in 2010, and only slightly more than a quarter of these adults were seen by a dentist. We also found that children--many of whom qualify for public coverage through Medicaid and the Children's Health Insurance Program--generally maintained or improved their access to care during the same period. This provides a reason for optimism about the ability of the coverage expansion in the Affordable Care Act to improve access for adults, but it suggests that eliminating the law or curtailing the coverage expansion could result in continued erosion of adults' access to care.