Geospatial Analysis of Access to Emergency Cesarean Delivery for Military and Civilian Populations in the US

The Comparative Effectiveness and Provider-induced Demand Collaboration Project: A Pioneering Military-Civilian Academic Partnership to Build Health Services Research Capacity for the Military Health System

INTRODUCTION

Like civilian health systems, the United States Military Health System (MHS) confronts challenges in achieving the aims of reducing cost, and improving quality, access, and safety, but historically has lacked coordinated health services research (HSR) capabilities that enabled knowledge translation and iterative learning from its wealth of data. A military-civilian academic partnership called the Comparative Effectiveness and Provider-Induced Demand Collaboration (EPIC), formed in 2011, demonstrated early proof-of-concept in using the MHS claims database for research focused on drivers of variation in health care. This existing partnership was reorganized in 2015 and its topics expanded to meet the need for HSR in support of emerging priorities and to develop current and HSR capacity within the MHS.

MATERIALS AND METHODS

A Donabedian framework of structure, process, and outcomes was applied to support the project, through a core of principal investigators, researchers, analysts, and administrators. Within this framework, new researchers and student trainees learn foundations of HSR while performing secondary analysis of claims data from the MHS Data Repository (MDR) focusing on Health and Readiness, Pediatrics, Policy, Surgery, Trauma, and Women's Health.

RESULTS

Since 2015, the project has trained 25 faculty, staff, and providers; 51 students and residents; 21 research fellows across multiple disciplines; and as of 2022, produced 107 peer-reviewed publications and 130 conference presentations, across all five themes and six cores. Research results have been incorporated into Federal and professional policy guidelines. Major research areas include opioid usage and prescribing, value-based care, and racial disparities. EPIC researchers provide direct support to MHS leaders and enabling expertise to clinical providers.

CONCLUSIONS

EPIC, through its Donabedian framework and utilization of the MHS Data Repository as a research tool, generates actionable findings and builds capacity for continued HSR across the MHS. Eight years after its reorganization in 2015, EPIC continues to provide a platform for capacity building and knowledge translation.

Environmental Justice Index and adverse pregnancy outcomes

BACKGROUND

The Environmental Justice Index is a tool released by the Centers for Disease Control and Prevention that quantifies and ranks the environmental burden and social vulnerability of each census tract. Racial and ethnic disparities in adverse pregnancy outcomes are well established. The relative contributions of individual (person-level) and environmental (neighborhood-level) risk factors to disease prevalence remain poorly understood.

OBJECTIVE

This study aimed to determine whether the Environmental Justice Index is associated with adverse pregnancy outcomes after adjustment for individual clinical and sociodemographic risk factors.

STUDY DESIGN

This was a retrospective cross-sectional study of all patients who delivered a singleton newborn at ≥23 weeks of gestation between January 2019 and February 2022 at 7 hospitals within a large academic health system in New York. Patients were excluded if their home address was not available, if the address could not be geocoded to a census tract, or if the census tract did not have corresponding Environmental Justice Index data. Patients were also excluded if they had preexisting diabetes or hypertension. For patients who had multiple pregnancies during the study period, only the first pregnancy was included for analysis. Clinical and demographic data were obtained from the electronic medical record. Environmental Justice Index score, the primary independent variable, ranges from 0 to 1. Higher Environmental Justice Index scores indicate communities with increased cumulative environmental burden and increased social vulnerability. The primary outcome was adverse pregnancy outcome, defined as the presence of ≥1 of any of the following conditions: hypertensive disorders of pregnancy, gestational diabetes, preterm birth, fetal growth restriction, low birthweight, small for gestational age newborn, placental abruption, and stillbirth. Multivariable logistic regression was performed to investigate the relationship between Environmental Justice Index score and adverse pregnancy outcome, adjusting for potential confounding variables, including body mass index group, race and ethnicity group, advanced maternal age, nulliparity, public health insurance, and English as the preferred language.

RESULTS

A total of 65,273 pregnancies were included for analysis. Overall, adverse pregnancy outcomes occurred in 37.6% of pregnancies (n=24,545); hypertensive disorders of pregnancy (13.4%) and gestational diabetes (12.2%) were the most common adverse pregnancy outcome conditions. On unadjusted analysis, the strongest associations between Environmental Justice Index score and individual adverse pregnancy outcome conditions were observed for stillbirth (odds ratio, 1.079; 95% confidence interval, 1.025-1.135) and hypertensive disorders of pregnancy (odds ratio, 1.052; 95% confidence interval, 1.042-1.061). On multivariable logistic regression, every 0.1 increase in Environmental Justice Index score was associated with 1.4% higher odds of adverse pregnancy outcome (adjusted odds ratio, 1.014; 95% confidence interval, 1.007-1.021). The strongest associations with adverse pregnancy outcomes were observed with well-established clinical and social risk factors, including class 3 obesity (adjusted odds ratio, 1.710; 95% confidence interval, 1.580-1.849; reference: body mass index <25 kg/m2) and certain race and ethnicity groups (reference: non-Hispanic White), particularly Asian and Pacific Islander (adjusted odds ratio, 1.817; 95% confidence interval, 1.729-1.910), and non-Hispanic Black (adjusted odds ratio, 1.668; 95% confidence interval, 1.581-1.760) people.

CONCLUSION

Environmental Justice Index score is positively associated with adverse pregnancy outcomes, and most strongly associated with stillbirth and hypertensive disorders of pregnancy. Geospatial analysis with Environmental Justice Index may help to improve our understanding of health inequities by identifying neighborhood characteristics that increase the risk of pregnancy complications.

Geospatial distribution of relative cesarean section rates within the USA

Objective

To evaluate the existence of statistically significant clusters of Cesarean section rates at the county level and assess the relationship of such clusters with previously implicated socioeconomic factors.

Results

County-level obstetrics data was extracted from March of Dimes, originally sourced from National Center for Health Statistics. County-level demographic data were extracted from the US Census Bureau. Access to obstetricians was extracted from National Provider Identifier records. Rural counties were identified using Rural Urban Commuting Area codes developed by the department of agriculture. The dataset was geospatially analyzed using Moran’s I statistic, a metric of local spatial autocorrelation, to identify clusters of increased or decreased Cesarean section rates. The American South, especially the Deep South, is a major cluster of increased Cesarean section rates. As a general but not absolute pattern, the American West and Midwest had lower Cesarean section rates than the Northeast. Focal areas of increased Cesarean section rates included the Kansas-Nebraska border, Michigan’s upper peninsula, and the New York City metropolitan area. The gross geospatial differences were not explained by rurality, obstetric access, or ethnic and racial factors alone.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13104-022-06141-w.