County-Level Associations Between Pregnancy-Related Mortality Ratios and Contextual Sociospatial Indicators

Abstract

Objective: To characterize county-level differences in pregnancy-related mortality as a function of sociospatial indicators.

Methods: We conducted a cross-sectional multilevel analysis of all pregnancy-related deaths and all live births with available ZIP code or county data in the Pregnancy Mortality Surveillance System during 2011-2016 for non-Hispanic Black, Hispanic (all races), and non-Hispanic White women aged 15-44 years. The exposures included 31 conceptually-grounded, county-specific sociospatial indicators that were collected from publicly available data sources and categorized into domains of demographic; general, reproductive, and behavioral health; social capital and support; and socioeconomic contexts. We calculated the absolute difference of county-level pregnancy-related mortality ratios (deaths per 100,000 live births) per 1-unit increase in the median absolute difference between women living in counties with higher compared with lower levels of each sociospatial indicator overall and stratified by race and ethnicity.

Results: Pregnancy-related mortality varied across counties and by race and ethnicity. Many sociospatial indicators were associated with county-specific pregnancy-related mortality ratios independent of maternal age, population size, and Census region. Across domains, the most harmful indicators were percentage of low-birth-weight births (absolute ratio difference [RD] 6.44; 95% CI 5.36-7.51), percentage of unemployed adults (RD 4.98; 95% CI 3.91-6.05), and food insecurity (RD 4.92; 95% CI 4.14-5.70). The most protective indicators were higher median household income (RD -2.76; 95% CI -3.28 to -2.24), percentage of college-educated adults (RD -2.28; 95% CI -2.81 to -1.75), and percentage of owner-occupied households (RD -1.66; 95% CI -2.29 to -1.03). The magnitude of these associations varied by race and ethnicity.

Conclusion: This analysis identified sociospatial indicators of pregnancy-related mortality and showed an association between pregnancy-related deaths and place of residence overall and stratified by race and ethnicity. Understanding county-level context associated with pregnancy-related mortality may be an important step towards building public health evidence to inform action to reduce pregnancy-related mortality at local levels.

Fig. 1.. Heterogeneity in measures of association between sociospatial indicators and pregnancy-related mortality ratios for non-Hispanic Black women and non-Hispanic White women. The pregnancy-related mortality ratio is the number of pregnancy-related deaths per 100,000 live births. Each point represents the ratio difference in the pregnancy-related mortality ratio. The ratio difference estimates the difference in the pregnancy-related mortality ratio between women living in counties that differ by 1 standardized unit (eg, the median absolute difference). *P<.05, ^†P<.01. P-values refer to the statistical significance of the test for heterogeneous effects of each sociospatial indicator by race and ethnicity (eg, for non-Hispanic Black women and non-Hispanic White women). Domains: demographic (A); general, reproductive, and behavioral health (B); social capital and support (C); socioeconomic (D). GED, general education development test; GP, general practitioner.