Purpose

To learn the size, composition, and scholarly output of biostatistics, epidemiology, and research design (BERD) units in U.S. academic health centers (AHCs).

Method

Each year for four years, the authors surveyed all BERD units in U.S. AHCs that were members of the Clinical and Translational Science Award (CTSA) Consortium. In 2010, 46 BERD units were surveyed; in 2011, 55; in 2012, 60; and in 2013, 61.

Results

Response rates to the 2010, 2011, 2012, and 2013 surveys were 93.5%, 98.2%, 98.3%, and 86.9%, respectively. Overall, the size of BERD units ranged from 3 to 86 individuals. The median FTE in BERD units remained similar and ranged from 3.0 to 3.5 FTEs over the years. BERD units reported more availability of doctoral-level biostatisticians than doctoral-level epidemiologists. In 2011, 2012, and 2013, more than a third of BERD units provided consulting support on 101 to 200 projects. A majority of BERD units reported that between 25% and 75% (in 2011) and 31% to 70% (in 2012) of their consulting was to junior investigators. More than two-thirds of BERD units reported their contributions to the submission of 20 or more non-BERD grant or contract applications annually. Nearly half of BERD units reported 1 to 10 manuscripts submitted annually with a BERD practitioner as the first or corresponding author.

Conclusions

The findings regarding BERD units provide a benchmark against which to compare BERD resources and may be particularly useful for institutions planning to develop new units to support programs such as the CTSA.

Background

Literature suggests that maternal exposure to persistent organic pollutants (POPs) may influence child neurodevelopment. Evidence linking prenatal POPs and autism spectrum disorder has been inconclusive and few studies have examined the mixture effect of the POPs on autism-related traits.

Objective

To evaluate the associations between prenatal exposure to a mixture of POPs and autism-related traits in children from the Early Autism Risk Longitudinal Investigation study.

Methods

Maternal serum concentrations of 17 POPs (11 polychlorinated biphenyls [PCBs], 4 polybrominated diphenyls [PBDEs], and 2 persistent pesticides) in 154 samples collected during pregnancy were included in this analysis. We examined the independent associations of the natural log-transformed POPs with social, cognitive, and behavioral traits at 36 months of age, including Social Responsiveness Scale (SRS), Mullen Scales of Early Learning-Early Learning Composite (MSEL-ELC), and Vineland Adaptive Behavior Scales (VABS) scores, using linear regression models. We applied Bayesian kernel machine regression and quantile g-computation to examine the joint effect and interactions of the POPs.

Results

Higher ln-PBDE47 was associated with greater deficits in social reciprocity (higher SRS score) (β = 6.39, 95% CI: 1.12, 11.65) whereas higher ln-p,p'-DDE was associated with lower social deficits (β = -8.34, 95% CI: -15.32, -1.37). Positive associations were observed between PCB180 and PCB187 and cognitive (MSEL-ELC) scores (β = 5.68, 95% CI: 0.18, 11.17; β = 4.65, 95% CI: 0.14, 9.17, respectively). Adaptive functioning (VABS) scores were positively associated with PCB170, PCB180, PCB187, PCB196/203, and p,p'-DDE. In the mixture analyses, we did not observe an overall mixture effect of POPs on the quantitative traits. Potential interactions between PBDE99 and other PBDEs were identified in association with MSEL-ELC scores.

Conclusions

We observed independent effects of PCB180, PCB187, PBDE47, and p,p' DDE with ASD-related quantitative traits and potential interactions between PBDEs. Our findings highlight the importance of assessing the effect of POPs as a mixture.

Background

Drinking water is a common source of exposure to inorganic arsenic. In the US, the Safe Drinking Water Act (SDWA) was enacted to protect consumers from exposure to contaminants, including arsenic, in public water systems (PWS). The reproductive effects of preconception and prenatal arsenic exposure in regions with low to moderate arsenic concentrations are not well understood.

Objectives

This study examined associations between preconception and prenatal exposure to arsenic violations in water, measured via residence in a county with an arsenic violation in a regulated PWS during pregnancy, and five birth outcomes: birth weight, gestational age at birth, preterm birth, small for gestational age (SGA), and large for gestational age (LGA).

Methods

Data for arsenic violations in PWS, defined as concentrations exceeding 10 parts per billion, were obtained from the Safe Drinking Water Information System. Participants of the Environmental influences on Child Health Outcomes Cohort Study were matched to arsenic violations by time and location based on residential history data. Multivariable, mixed effects regression models were used to assess the relationship between preconception and prenatal exposure to arsenic violations in drinking water and birth outcomes.

Results

Compared to unexposed infants, continuous exposure to arsenic from three months prior to conception through birth was associated with 88.8 g higher mean birth weight (95% CI: 8.2, 169.5), after adjusting for individual-level confounders. No statistically significant associations were observed between any preconception or prenatal violations exposure and gestational age at birth, preterm birth, SGA, or LGA.

Conclusions

Our study did not identify associations between preconception and prenatal arsenic exposure, defined by drinking water exceedances, and adverse birth outcomes. Exposure to arsenic violations in drinking water was associated with higher birth weight. Future studies would benefit from more precise geodata of water system service areas, direct household drinking water measurements, and exposure biomarkers.