Doctoral Defense - Courtney Walker

Nov 16, 2021 to Nov 16, 2021

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An Assessment of Early-Onset Hypertensive Disorders of Pregnancy, Environmental Metal Exposures, and Geocoding Precision of Kentucky Birth Records, 2008-2017



Using live and stillbirth records from Kentucky (2008-2017), this dissertation assessed the county-level prevalence and geospatial patterns of early-onset hypertensive disorders of pregnancy (eHDP); examined the geocoding precision of addresses recorded on birth records, and evaluated the association between individual risk factors and environmental metal exposures on eHDP prevalence. After adjusting for maternal demographic factors and pre-existing health conditions, we observed that eHDP prevalence was 38% higher (aPR=1.38, 95%CI:1.16, 1.64) in counties with the highest prevalence of married women (>53.8%) compared to lower prevalence areas (<43%). We also found that counties with the highest prevalence of maternal obesity (>31.6%) had a 20% higher prevalence of eHDP (aPR=1.20, 95%CI:1.00, 1.44) compared to counties with lower obesity prevalence (<22.6%) after adjustment. We also identified two county-level clusters of eHDP in Appalachia.


In the assessment of geocoding precision, we found that while address geocoding precision has improved over time, addresses of rural Black women were more likely to imprecisely geocode (aOR=1.41, 95%CI:1.22, 1.62) than rural White women.


Adjusting for geocoding imprecision, we further assessed demographic and environmental factors associated with eHDP prevalence by augmenting records with census micro-block group toxicity concentration estimates of arsenic, cadmium, chromium, lead, and mercury from the Risk Screening Environmental Indicators (RSEI) model. Using a latent class analysis, we identified four classes of metal exposures. After adjusting for geocoding, imprecision, maternal demographics, and pre-existing health conditions, we found that women with a higher probability of lead and chromium exposure had a 22% higher prevalence of eHDP (aPR=1.22, 95%CI:1.04, 1.44) compared to women with a low probability of exposure to other considered metals. This study indicates an association between lead, chromium, and eHDP, even after adjusting for important covariates. Further research refining the use of RSEI scores and other exposures in association with eHDP is needed.